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GEEntellisys

Entellisys 4.0Low-Voltage Switchgear

Application Guide


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Contents

Section Page1 Introduction 12 General Description 33 System Architecture 54 Minimizing Potential Exposure to Arc Flash Energy 115 EntelliGuard Breaker 196 EntelliGuard Messenger 25

7 Protection 278 Metering 419 Events and Diagnostics 47

10 Discrete I/O 5311 Control 5512 EntelliGuard Preventative Maintenance 5913 User Interface - HMI 6114 Remote Communication 6715 Design Considerations 6916 Layout and Sizing 7317 Appendices 97

A. Guide Form Specification 97B. Type Tests 105C. Standard and Optional Features 107D. Time Current Curves 109


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Entellisys Low-Voltage Switchgear

Section 1. Introduction

Since electricity was first harnessed, protecting circuits against faults andoverloads has been a persistent challenge. Circuit protection technology hasadvanced over the years, with todays modern fuses, bimetallic trips, magnetic

trips, and powerful electronic trips providing a wide range of choices. However,from the simplest fuse to the most complex digital trip, all of these devices havea common limit; all are only able to consider the current in the conductors theydirectly protect. Because of this limitation, these mechanisms are oblivious tothe larger systems and changing environments within which they operate. Allmodern trip systems can only react to what they knowthe current magnitudeand time.

Entellisys Low-Voltage Switchgear is the first circuit-protection technologythat overcomes this limitation. The Entellisys Single-Processor Concept basescontrol of every circuit breaker in the switchgear upon what is best for theentire system under the exact conditions in the system at that moment. Eachtrip function is no longer limited to the current information available at itsparticular circuit. With Entellisys, each circuit breaker is controlled with fullinformation about every current, voltage, and circuit breaker in the switchgear

Entellisys is the first system to provide the power of knowledge about the

entire switchgear lineup. This power can be used by the engineer to improveprotection, by the installing contractor to shorten installation time, by themaintenance manager to save maintenance costs, and by the owner to adaptthe equipment to the dynamic needs of the facility. Entellisys helps to reducecosts, shorten schedules, and increase reliability throughout the processof designing, installing, maintaining, and owning your low-voltage powerdistribution switchgear.

This application guide will introduce you to the power of Entellisys and how itcan help you to deliver electrical power within your facility more reliably thanever possible before.

Welcome to the world of Entellisys.


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Entellisys Low-Voltage SwitchgearSection 2. General Description

Entellisys low-voltage switchgear providesprotection, control, and monitoring in a flexiblepackage that will change the way you think aboutswitchgear. All of this capability is integrated intoindustrial-duty equipment built to ANSI standardsand uses 100% rated EntelliGuard low-voltage

power circuit breakers. Entellisys low-voltageswitchgear is built upon the same design as therugged AKD architecture, with almost 60 years ofproven reliability. The Entellisys equipment designis based on the AKD-10 structure. EntelliGuardlow-voltage power circuit breakers are an extensionof the robust WavePro design, with years ofexperience in all types of switchgear environments.

Entellisys low-voltage switchgear is available withthe following maximum nominal ratings:

600 volts ac 5000 amps ac 50/60 Hz 200 kA symmetrical short circuit interrupting

Entellisys switchgear is designed to have more marginwithin its ratings to provide maximum continuityof service for those applications subject to severeduty, such as process industries, data centers,healthcare facilities, and power systems requiringcontinuous operation. It is designed to be operatedin an ambient temperature between -30C and 40C

and is available in indoor construction. The bussizing is based on temperature rise rather than oncurrent density (as with switchboard construction).

EntelliGuard low-voltage power circuit breakers areavailable for Entellisys switchgear in six frame sizes:800A, 1600A, 2000A, 3200A, 4000A and 5000A.

All circuit breakers can be equipped with currentlimiting fuses. The 800A and 1600A frames areprovided with integrally mounted fuses, while aseparate fuse carriage is required for 2000A through

5000A type breakers.

Entellisys switchgear houses low-voltage powercircuit breakers and the Entellisys system compo-nents in single or multiple source configurations.Entellisys switchgear can be applied either as apower distribution unit or as part of a unit substation.

Entellisys switchgear is manufactured in GEs ISO9001 certified facility in Burlington, Iowa. It complies

with ANSI standards C37.20.1 and NEMA SG-5, anis UL Listed to standard 1558, file no. E76012. Theswitchgear has been conformance tested accordingto ANSI C37.51. Entellisys switchgear also meetsthe requirements for the CSA label. Entellisysequipment has been tested and meets the IBC-

2003 requirements.

ANSI standards require that switchgear operatesat the ratings of devices installed. Switchgearshort circuit ratings are based on two 30-cyclewithstand tests with a 15-second interval betweetests, performed at 15% power factor and 635vAC maximum.

GEs Entellisys low-voltage switchgear can help youmeet todays challenges for greater productivity,increased operator safety, and improved equipmenreliability and maintainability.

Entellisys low-voltage switchgear offers:

Safety Human interface located away fromthe equipment for monitoring, control, andremote racking. Advanced zone protectionprovides fast fault identification while providingselectivity. Reduced Energy Let Through modelowers the potential arc flash energy whensomeone is going to be near the equipment.

Reliability Redundant systems, selective pro-

tection, and predictive maintenance data aids inmaximizing uptime and minimizing downtime.

Flexibility Add or change system functionalitywith no hardware changes, making it easy to keepthe equipment up to date to meet changing needs

The Entellisys architecture enables the system toprovide these unique advantages.


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Entellisys Low-Voltage SwitchgearSection 3. System Architecture

Figure 3.1

Historically, advances in power distributionprotection, control, and monitoring have translatedinto many separate components: circuit breakerswith trip units controlling them, meters, PLCs used forcontrol, and any other relays or devices necessary.These solutions force multiple, independent devices

to execute multiple, independent actions, not tomention the many wiring terminations required. Theoutcome is complex systems that result in circuitprotection still dependent upon individual deviceslooking at mere subsets of the available informationwithin a lineup. Thus, protection and selectivity aresub-optimized. Add to that the challenge of linkingthese many multiple devices to remote locationsvia communication networks and you have acomplex system that is not designed to providemaximum protection, monitoring, and control.

There is a better way.

Entellisys is an integrated switchgear systemthat uses a single central processing unit (CPU) toperform all of the protection, monitoring, control,communication, and diagnostic functions that couldbe required for a low-voltage switchgear lineup.Entellisys replaces discrete devices and associatedpoint-to-point wiring that are used to perform thesefunctions in traditionally designed switchgear. Thebasic system uses a structured hardware design

consisting of the CPU, a digital communicationnetwork, current sensors, device electronics for thecircuit breaker, control power, voltage transformers,and an HMI (human-machine interface). RedundantCPUs, communication networks, and critical devicesare standard, improving the layers of backup when

compared to traditional switchgear. Figure 3.1depicts the Entellisys system architecture.

All Entellisys components are designed to belocated within the low-voltage switchgear line-upFollowing is a description of the major Entellisys

system components.

EntelliGuard Circuit BreakerThe EntelliGuard circuit breaker is built upon thesame proven design as the WavePro metal-framelow-voltage power circuit breaker, except that ithas no internal trip unit or internal current sensors.The circuit breaker is a non-automatic device andthe current sensors and electronics are attachedto the breaker cubicle. This allows all breakers of agiven frame size to be interchangeable regardlessof the circuits requirements for trip rating andovercurrent trip characteristics.

The EntelliGuard circuit breaker is an ANSI-rated,UL 1066-listed draw-out circuit breaker. The circuibreaker is supplied in two forms, manually or electrically operated. Electrically operated breakers canbe closed, opened, and tripped by way of EntellisysManually operated breakers are only tripped byEntellisys. The EntelliGuard circuit breaker is availablin 800, 1600, 2000, 3200, 4000, and 5000 ampereframe sizes with short-circuit interrupting ratings

from 30kA to 200kA. Accessories for theEntelliGuard circuit breaker include a bell alarm withmechanical lockout (local lockout) and a networkinterlock (for electrically operated breakers only).Details of the EntelliGuard circuit breaker, operationand accessories are covered in Section 5.


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Section 3. System Architecture

EntelliGuard MessengerThe EntelliGuard Messenger is the electronic interfacebetween the Entellisys systems central processingunits and the EntelliGuard circuit breaker. Theprimary duties of the Messenger are to function asan analog-to-digital converter of voltage and current

signals at the circuit breaker, communicate the rawelectrical data to the systems central processingunits, receive operating instructions from the centralprocessing units, and execute those instructionson the EntelliGuard circuit breaker. The Messengeralso provides backup instantaneous and overloadprotection in the rare case communication is lostwith both CPUs. Under these conditions theMessenger is powered by the current sensors,similar to trip units in traditional low-voltageswitchgear. Details of the specific functions of theEntelliGuard Messenger are covered in Section 6.

Current SensorsEach breaker cubicle is furnished with a set ofthree-phase current sensors. The current sensorshave primary ratings of 150, 400, 800, 1600, 2000,3200, 4000, and 5000 amps. The secondary ratingof all current sensors is 600 milli-amps. The analogoutput of the current sensor is connected to theEntelliGuard Messenger via a plug-in connector. Allcurrent sensors are provided with built-in open circuitprotection so separate open circuit protection and

shorting devices are not required. Current sensorsrated 150 amps through 2000 amps are designedas a three-phase unit. Current sensors rated 3200amps through 5000 amps are designed as single-phase units. 150 and 400 amp current sensorsare also provided with a clamp circuit to limitvoltage on the Messenger electronics during highmagnitude faults.

Current sensors can be located on the upper orlower primary disconnects in the circuit breakercubicle. Location of the current sensor for the

standard overcurrent protective functions is notcritical but for the more advanced protection func-tions, such as bus differential, placement of thecurrent sensor becomes more critical. For purposesof standardization, the current sensors for sourcebreakers (transformer secondary breakers, generatorbreakers, etc.) are located on the source side of thecircuit breaker cubicle. This will typically be on theupper primary disconnects but can be on the lowerprimary disconnects for reverse-fed breakers.Current sensors for feeder breakers will be located

on the load side of the breaker cubicle. Typically,this will be the lower primary disconnects in thecubicle unless the feeder cubicle is reverse-fed.

Potential (Voltage) TransformersPotential or voltage transformers are used to convert

power system level voltages to voltages that canbe used by Entellisys. Voltage transformers aresupplied in two forms two units connected in opendelta on the primary and secondary or three unitsconnected wye on the primary and secondary.The transformers are rated for either line-to-linevoltages (open delta) or line-to-neutral voltages(wye). The secondary voltage of each transformeris 18 volts.

The output of the voltage transformers is connectedto at least one EntelliGuard Messenger in the line-up.All other Messengers can reference this voltagefor their metering and protective relay functions.This allows the voltage to be sampled at onelocation but applied to as many breakers in theswitchgear line-up as necessary. For a single-source switchgear line-up, the voltage transformerscan be connected to the Messenger for the maincircuit breaker and all feeder breaker Messengerscan be referenced to the voltage at the main circuitbreaker Messenger. There is no need to connectthe voltage signal to all of the feeder Messengers

for individual metering at the feeders.

Likewise for multi-source switchgear line-ups, thevoltage for the feeders can be referenced fromeither main circuit breaker Messenger. In the caseof a double-ended switchgear line-up, the feederson a bus can be referenced to their respectivemain circuit breaker voltage signals under normaloperating conditions. When a main breaker isopened and the tie breaker closed, programmingin the Entellisys system can be set to switch thevoltage reference to the opposite main breaker.

This eliminates the need for bus-connected voltagetransformers or complex transfers on the secondaryof the voltage transformers to maintain accuratefeeder metering.

CPUThe intelligence behind the Entellisys system is thecentral processing unit (CPU). The CPU processesdata from up to 30 circuit breakers within theswitchgear line-up and, based on the systemprogramming, will perform the required metering,


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Figure 3.2

protective, and control functions. Inputs to the CPUare the electrical current data from each circuit,voltage data from each power source, status fromeach circuit breaker (open, closed, tripped, locked-out,closing spring state, breaker primary and secondarydisconnect position), and the status of optional

Digital I/O (up to 128 points). This information is usedby the CPU to determine the low-voltage distributionsystem configuration and issue any control orprotective function instructions to the appropriatecircuit breakers via the Messengers.

Internal CommunicationsEntellisys uses a deterministic communicationsystem to provide the necessary fast, reliable, andpredictable transfer of data between the CPU andMessengers. The communication system inEntellisys is structured to yield fixed latency andsub-cycle transmission times between the CPUand all other devices connected to the internalcommunication system. The overcurrent protectivefunctions in the CPU run at the highest priority andthe system is sampling data from each circuitbreaker and issuing commands to the breakersevery 8.33 milliseconds or every half cycle.

The internal communications network uses com-mercial, off-the-shelf, Ethernet network switches toconnect the Messengers to the CPUs. The network

switch has a port for every Messenger so that eachcircuit breaker cubicle has two dedicated homeruns back to the CPU. The internal communications

network is a closed system, providing maximumsecurity for the critical protective, control, andmetering functions at each circuit breaker.

System RedundancyEntellisys has redundancy at every key system

component to insure operation under the mostadverse system and environmental conditions.Starting at the breaker cubicle level, the EntelliGuardMessenger is provided with dual power supplyinputs and redundant communication ports. Eachcommunication port is connected to a redundantcommunication cable that terminates at redundannetwork communication switches. Each communication switch is connected to a redundant,synchronized central processing unit. MessengersCPUs, and communication switches are all poweredfrom redundant UPSs fed from dual control powersources through redundant control power transferelays. Figure 3.2 depicts the multiple levels ofredundancy that are standard in Entellisys.

An additional level of redundancy is the backupprotection provided by the Messengers in theevent both CPUs are not communicating with theMessenger. In this rare case, the Messenger ispowered from the current sensors and providesoverload and short circuit protection. In otherwords, in a worse case scenario, the system

provides overcurrent protection that is similar tothe only protection offered in many traditionalswitchgear lineups today.


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SynchronizationSynchronization between the two central processors(CPUs) is maintained through a hardware SyncClock on CPU-A and a connection to CPU-B. Thiskeeps both CPUs running in a synchronized mannerso that if monitoring or control is switched from

one CPU to the other, the execution is seamless. Ifdesired, the CPUs and HMI can be synchronized usinga Simple Network Time Protocol (SNTP) time server.This enables each Entellisys system to be synchronizedboth with another Entellisys system as well as withother devices or systems in the facility-wide system.

Control Power System, Including UPSSwitchgear-connected, single-phase control powertransformers with 120v AC secondaries supplycontrol power for all of the Entellisys components.Ideally, there should be two control power trans-formers connected to different power sources,to provide redundant control power. This isstraightforward for multiple-source switchgearline-ups where each source (utility or generator) willhave a control power transformer. For single-endedline-ups, the redundant control power source can becustomer-supplied or another switchgear single-phase control power transformer connected todifferent phases.

Each 120v AC control power source is connected

to a control power transfer relay and the output ofeach transfer relay is connected to a UPS. Each UPSis a true VFI (voltage and frequency independent)on-line double conversion high performance device.All Entellisys components are powered from theoutput of the two UPSs except the spring chargingmotors for the electrically operated circuit breakers.The spring charging motors are connected aheadof the UPS on the output of the control powertransfer relay.

HMI (Human-Machine Interface)

The HMI is the system interface providing touch-screen access to screens for viewing the status ofthe Entellisys system itself (system and componenthealth), the distribution system status (meteringdata for each circuit breaker, breaker status),protective settings for each circuit breaker (over-current protection, protective relays), alarm settingsand status (for each circuit breaker and for thesystem), sequence-of-events log, and capturedwaveforms. An HMI is often located within theswitchgear line-up, in an auxiliary cubicle, and is

referred to as a local HMI. A redundant HMI can alsobe installed. This is common in substations that consistof one Entellisys system split into two lineups andin which each lineup has an HMI. Once the systemis programmed, the HMI is not a critical componentto allow Entellisys to provide its protective functions.

Entellisys uses password protection to providevarious levels of access to system information.The owner can set up different levels of accessranging from a Guest level, where only meteringand status information can be viewed, to anAdministrator level, which allows access to breakerprotection settings and control of the circuitbreakers. Customized user groups can also bedefined that will give each group specific permissionsto view and/or access items such as breaker control,viewing the sequence of events log, viewing settings,changing settings, etc.

Near-Gear HMIEntellisys offers the convenient solution of providingmonitoring and control outside the hazardous arcflash zone by using a Near-Gear HMI. The near-gearHMI has the same user capabilities as the localHMI and can be positioned up to 300 feet (wiringdistance) from the switchgear and CPU. Availablein a stand-alone stack or a wall-mounted box, theNear-Gear HMI can either be in addition to the

local HMI or replace it in the lineup.

Near-Gear Entellisys Control StackIf your application calls for keeping control, moni-toring and Entellisys system maintenance outsidethe arc flash zone, the Near-Gear Entellisys controlstack meets these needs. The HMI and all of thekey redundant Entellisys components, the CPUs,UPSs and Discrete I/O are located in a single stackthat can be placed up to 300 feet (cable length)from the switchgear lineup. This enables monitor-ing and control via the HMI and the performance

of routine Entellisys component maintenance,such as upgrading software options or replacingUPS batteries, outside the arc flash zone.

Remote HMI and External CommunicationsAdditional monitoring and control stations canbe added to the system by adding remote HMIsoftware to a personal computer that is or can beinstalled on the owners local area network. Up toeight local and remote HMIs can communicatewith Entellisys at any given time.


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All remote communications takes place at the HMIlevel and has no impact on the performance of theclosed internal communications level between theEntelliGuard Messengers and the central processingunits. No external communications are permittedto take place with the CPUs, thereby insuring the

security of the operating system.

The physical connection for remote communicationis at the system interface Ethernet switch betweenthe CPUs and the HMI. Additional ports on this 8-port switch allow up to five external connectionsusing CAT5 cable. An optional 9-port hub is availableto allow external communication via fiber opticcable. Up to four local HMIs can be connected tothe system interface Ethernet switch, and a LANconnection can support multiple remote HMIs. Alocal HMI can block out other HMIs (local orremote) from controlling the circuit breakers in theswitchgear. This provides secure control for thebreakers during any maintenance operations.

Connections to remote HMIs on a LAN can bethrough a VPN (virtual private network) firewalldevice. The VPN only allows pre-defined remote IPaddresses to have access to the system, furtherenhancing the security of Entellisys.

Entellisys can also be interfaced with external

monitoring and control systems via remote com-munications. Entellisys communicates with externalsystems via Modbus TCP protocol, providing an open,common language for interfacing with SCADA,building automation, and process systems.

Discrete I/OEntellisys can interface with external monitoringand control systems in several ways. The mostconventional means is by way of Discrete inputsand outputs. Up to 128 I/O points can be definedfor use in monitoring and control systems. Discrete

I/O can be provided in non-redundant or redundantconfigurations. Discrete I/O is designed to acceptand provide dry contact operations. A more detaileddiscussion of Discrete I/O occurs in Section 10.

Expansion CapabilitiesEntellisys switchgear is designed to be easilymodified or expanded to handle change in orincreased loading.

Metering functions, system-wide waveform captureand most protection can be easily changed withsoftware upgrades to the CPUs, requiring noadditional hardware. Consequently it is possible toadd features to one CPU while the other one isoperating, and then update the second CPU

when the upgraded CPU is returned to operatingmode. This capability is useful for the life of theequipment, from the design, through manufactur-ing, to start-up and operation. Entellisys makes iteasy to keep the equipment up to date with ever-changing needs.

It is very common to specify fully equipped futurebreaker cubicles when ordering a substation orline-up. The fully equipped future breaker cubiclecontains line and load side primary disconnects,drawout rails, and a cutout in the cubicle door.Current sensors are located in the compartmentand a Messenger is placed above the breakercompartment. Adding a new feeder can then beas simple as removing a cover from the cubicledoor and installing the breaker as well as inputtingthe circuit breaker protection settings and datainto the CPUs via the HMI.

Standard bus configurations used in Entellisyshave provisions for future bus extension built in.Should the switchgear have no future breaker

compartments, additional vertical sections can bemechanically and electrically connected to theEntellisys line-up without modifications or the useof transition sections.

ConclusionThese are the building blocks of an Entellisys low-voltage switchgear lineup. The Entellisys architectureenables new, powerful protection, monitoring, andcontrol capability in a flexible system that can beupdated over the lifetime of the equipment. Thesecapabilities and application improvements are

discussed in more detail in the following sections.


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Entellisys Low-Voltage SwitchgearSection 4. Minimizing Potential Exposure to Arc Flash Energy

This section addresses the ownership and operationof Entellisys low-voltage switchgear for maximumreliability and minimal arc flash risk.

Low-voltage switchgear can be expected to havea long life within the facilitys electrical power

distribution system. It can reasonably be expectedthat, during that time, the equipment will need tobe operated and maintained, even modified andexpanded. Entellisys provides significant advantagesover more traditional technology for owning, operat-ing, and maintaining the equipment. This sectiondescribes some of Entellisyss inherent capabilitiesand how to use them to improve the ownershipexperience. The specific capabilities include:

Complete control, monitoring, setting capability andperforming routine Entellisys system maintenance

from a remote location, reducing the need tohave personnel near live electrical equipment. Remote racking device to allow racking in or out

of circuit breakers by operators well outside theflash protection boundary1. Operator safety isincreased by eliminating the need to stand nearthe gear while racking circuit breakers into orout from a live bus.

Fully selective fast protection to lower arc-flashenergy in case of an arcing fault within theequipment. The protection is fast enough to lowerPPE requirements and decrease the arc flash

protection boundary while maintaining completesystem selectivity.

Reduced Energy Let Through (RELT) mode enablesan operator to easily change the circuit breakersettings to more sensitive levels, potentiallyreducing the hazard risk category, prior to workingnear the equipment.

A family of fused circuit breakers provide current-limiting fuse performance across all circuit breakerframe sizes. Full current-limiting performance forall circuit breaker sizes provides optimum protectionat high-fault values.

Fully insulated and isolated bus to minimizepotential bus faults. Minimizing live conductivesurfaces reduces the probability of internalequipment faults due to contamination ormechanical damage.

Fully compartmentalized circuit breakers to min-imize arc fault transmission within the equipment.Grounded separation panels between circuitbreakers and barriers between the front breaker

cubicles and the rear bus and cable compartmentminimizes the probability of transmission of anarcing fault from one equipment area to another.

Circuit breakers use monitoring to drive need/use-based maintenance scheduling versus perioditime-based maintenance.

Self diagnostic features provide notification thata device needs to be evaluated or changed.

Flexible system design easily accommodatesadded or changed functionality. Entellisys makesit easy to modify installed equipment as the loarequirements change.

Below are general descriptions of how Entellisyslow-voltage switchgear provides more efficient andsafer operation and maintenance of your electricalequipment. The specifics of some of the capabilitieare covered in other sections of this publication.

Remote Control, Monitoring, and MeteringThe Entellisys system architecture makes remotemonitoring and control easy. The user interface tothe system is typically via a touchscreen HumanMachine Interface (HMI).

The Entellisys touchscreen (HMI) may be mounteddirectly on the switchgear lineup and/or as a NeaGear HMI either in a freestanding equipment stack owall mounted box. Another option is the Entellisys Nea

Gear Control stack where the HMI, CPUs and UPSsare located. The Near Gear modules may be located up to 300 cable feet away from the equipment

The HMI software can also be loaded on a remotecomputer connected to a local- or wide-area net-work, providing additional remote access to theequipment for monitoring or control.

All control and protection settings (other thanlong-time pickup) are made via the HMI software.All metering, status monitoring, event monitoring,

and even waveform data can be viewed throughthe HMI. Furthermore, to confirm that the circuitbreaker being viewed in the HMI screen is the sameone being checked in the physical equipment , theEntellisys Messenger includes a blue LED light thacan be switched on from the HMI software to verifycircuit breaker location. Keep in mind that the protection, metering and control is provided by theredundant CPUs and is independent of the HMI.

1 Flash protection boundary as defined in Article 130 of NFPA 70E, Standard for Electrical Safety in the Workplace. The distance at which the

incident energy equals 5 J/cm2 (1.2cal. cm2) for situations where clearing time is longer that 0.1 seconds or 6.24 J/cm2 (1.5cal/ cm2) where fault

clearing time is 0.1 seconds or faster.


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Section 4. Minimizing Potential Exposure to Arc Flash Energy

There are several benefits from this method ofinterfacing with the equipment versus the tradi-tional method of looking at individual meters, cir-cuit breaker trip units, and operating switches onthe front of the gear or buttons on the front of thecircuit breakers.

The use of a large screen allows the operator tosee multiple items simultaneously and to shift fromone circuit to another or viewing systemwideinformation simultaneously.

Perhaps more important, a remote HMI screen,whether on a computer or the Entellisys flat-paneldisplay, allows operators to be far enough awayfrom the gear that they need not expose them-selves to the risks associated with operating liveelectrical equipment. Specifically, the operatorcan be located outside the flash-protection zonedefined in NFPA 70E and need not wear cumber-some PPE to perform such duties as circuit breakerswitching, throwover control, or other routineoperational activities.

The Near Gear Control stack allows operators theadditional benefit of adding system functionalityor changing UPS batteries away from 480Vequipment, again making these proceduresavailable outside the flash-protection zone definedby NFPA 70E. The Near Gear Control stack includesthe HMI as well as the key redundant Entellisysdevices; the two CPUs, two UPSs and any

Discrete I/O.

For further details on how the HMI software functionssee Section 13.

Remote RackingThe electrically operated racking device allowsmaintenance personnel the ability to be up to 30feet away from a draw-out circuit breaker duringthe racking operation, as shown in Figure 4.1. Theelectric motor is operated using convenient 115v

AC power with a plug-in power cord. The gearbox iseasily attached to the front of the breaker with asliding latch connection. Allowing the user to bephysically removed from the circuit breaker rackingmechanics during operation provides peace of mindnot normally available in a low-voltage application.Furthermore, a circuit breaker may be opened via aremote HMI, so an operator can open a circuitbreaker before approaching it to attach the remoteracking mechanism.

Fully Selective Fast ProtectionSection 7 describes how Entellisys protective functionsprovide fast and selective protection. In addition tolowering equipment and conductor damage due tofaults within your power distribution system, Entellisyssfast-protection capability also reduces the potentialmagnitude of incident arc-flash energy, based on thecalculation methods in IEEE 1584 and NFPA 70E.

The potential incident energy resulting from anarcing fault is a function of the available short-circuitcurrent at the point where the fault occurs and the

time that the arcing fault current persists. The arcingcurrent is also a function of voltage and systemimpedance. The Entellisys protection algorithmsexcel in their ability to identify a fault current andtrip the right circuit breaker quickly; first, because

Figure 4.1Remote Racking Operation

Figure 4.2Calculated Incident Arc Flash Energy

110100

908070605040302010

0IBF 15 20 25 30 35 40 45 50 55 60 65

J/cm2

13.5 cycle clearing 5.5 cycle clearing 3 cycle clearing

HRC 1

HRC 2

HRC 3

480 volt system, high resistance grounded, 18 working clearance, fault located within anIEEE 1584 defined 20 inch square enclosure. Lines drawn under following assumptions: 480V, HRG, 18 working distance, enclosed fault 3 cycle = instantaneous, 5.5 = 1st time band and 13.5 cycle = 2nd time band clearing time


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of the short time delays and, second, because of thezone-based protection implemented in Entellisys.

The effect of clearing time on potential incidentenergy may be calculated with IEEE 1584 formulas.Figure 4.2 demonstrates the relationship between

clearing times and prospective bolted fault currenton potential incident energy for a 480v, high-resistance grounded system. Incident energy valuesfor a 480/277v solidly grounded system would beslightly lower. The values were calculated per IEEE1584-2002. The equations represent an 18-inch work-ing distance, 32-millimeter gap (typical of low-voltageswitchgear), and a 20-inch enclosure around the faultevent to represent a typical circuit breaker cubicle.

Note that a total clearing time of 3 cycles keeps theHRC at level 2 or below for systems with prospectiveshort-circuit currents of 65kA IC or less. Three cyclesrepresent the maximum clearing time for theinstantaneous function of any GE ANSI circuit breaker.The minimum time-delay band of an EntelliGuardcircuit breaker clears in 5.5 cycles. Figure 4.2demonstrates that this clearing time is able to keepthe circuits HRC at level 2 for prospective boltedfault values up to 40kA and at HRC 3 for bolted faultvalues of 65kA IC and above. Entellisyss secondtime-delay band clears in a maximum of 13.5 cycles.In 65kA systems, this clearing time will keep the

HRC in the level 3 range.

Specific settings may affect the HRC level for thefeeders zone of protection. An 800A or 1600A feederwithout instantaneous protection should achieve

a maximum HRC of 3 while maintaining completeselectivity. Judicious use of the instantaneouspickup should maintain the HRC at a maximum oflevel 2, with very good selectivity with downstreammolded-case feeder breakers.

The Entellisys system is able to employ time delaysas short as 0.025 seconds (25 milliseconds), theequivalent of 1.5 cycles pickup at 60 Hz. This fasttime band is sufficient to clear the instantaneousband of any current-limiting or fast molded-casecircuit breaker used below an EntelliGuard feederwith an instantaneous clearing time of 1.5 cycles oless. Any EntelliGuard circuit breaker set at minimumtime delay will clear at 0.092 seconds (5.5 cycles) oless for fault currents above the circuit breakersframe size, while maintaining complete selectivitywith at least one layer of fast molded-case circuitbreakers below. Figure 4.3 shows the time-currentplots for a 225A Spectra circuit breaker that isselective with the 800A ANSI EntelliGuard circuitbreaker above it.

To achieve better protection, it may be desirable tohave an instantaneous setting on the switchgearANSI circuit breaker that slightly limits the selectivitySince the molded-case circuit breaker is probablylocated in remote equipment, the possible faultcurrent at the circuit breaker may be significantly

lower. Furthermore, the most probable location ofa fault is at or near the load for that feeder circuitbreaker, further increasing the impedance to thefault location and thus lowering the fault current.If the fault is arcing, the actual fault current may

Figure 4.3800A Feeder Selectivity

Figure 4.41600A Feeder Select

An Entellisys minimum time delay band will be selective with the instantaneous band ofany Spectra circuit breaker shown with a clearing time band of 25 milliseconds or less.


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14

be still lower, allowing the molded-case circuitbreaker to function within its instantaneous range,while being completely selective with the 800Afeeder in the switchgear. A combination of minimumtime-delay band and instantaneous settings forboth 800A feeder circuit breakers allows the HRC

level within their zone of protection to stay at level2 or below for potential bolted faults up to 65kA.This scenario is similar with a 1600A EntelliGuardfeeder. The time-current plot shown in Figure 4.4demonstrates the potential curve relationshipbetween a 1600A ANSI feeder and a 600A molded-case Spectra circuit breaker.

Main bus protection on a traditional system isalways a challenge and forces the system designengineer to make some compromises. Traditionalselectivity can only be achieved by sacrificingprotection, since the main and tie circuit breakersmust be set with enough time delay to clear thedelay of the feeder circuit breakers fed from thebus. Often this requires the main to be set severaltime delays above its potential minimum. Fastertime delays allow some improvement in protection.Compare this to Entellisys. For Entellisys time delaysin a typical double-ended substation feeder, thetie and a main may be selective with the feederset at a minimum time delay of 0.025s, the tie at0.100s, and the main at 0.217s. The incident arc

flash energy that may be let through by devicesat these settings is shown in Figure 4.5 The maincircuit breaker is able to keep the bus at an HRClevel 4 for about 60kA IBF or less.

However, the Entellisys system can provide betterprotection with its zone-based protection function.As described in Section 7, Entellisys employs abus-differential algorithm with zone interlocking toprovide zone-based overcurrent protection for a widerange of fault values. This overcurrent protection

can be set from below the buss full current ratingup to the full short-circuit capability of the individualcircuit breakers. When set in this manner, the tie andmain circuit breakers can be operated at minimumtime delay for a wide range of fault values, whileproviding complete selectivity with the feeder circuitbreakers. The IEEE 1584-calculated arc flash incidentenergy for a 480v high-resistance grounded systemwithin a low-voltage switchgear cubicle operatingat the minimum time delay of 25 ms is able to remainat HRC 3 or below with up to 100kA IC available at480 volts. Delay-based coordination found in tra-ditional switchgear requires that the main circuitbreaker be set at one of the longer delays, while theEntellisys zone-based protection for the same buscan be set at minimum delay for all fault magnitudes,100% selectivity. With a longer delay (traditionalsystems), the calculated arc flash energy for a 65kAsystem is above HRC 4, while it is only slightly overHRC level 2 with the minimum time delay (Entellisys).

Because the bus-differential algorithm may be setas low as 20% of the largest CT on the bus, 4000A

bus-differential protection may be set as low as800A. The zone-interlocking algorithm functionsas high as the full short-circuit rating of the circuitbreaker. This allows the circuit breaker to operate

Figure 4.5Arc Flash Energy, Main Bus and Feeder with Selective Delays

180

160

140

120

100

80

60

40

20

0

IBF 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

J/cm2

Tie Main 1600A Feeder

HRC 4

HRC 3

HRC 2

Figure 4.6Arc Flash Energy, Main Bus, Feeder and Branch

200

180

160

140

120

100

80

60

40

20

0

IBF 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

J/cm2

1600A CB 1600A Fuse

HRC 4

HRC 3

4000A Bus 2000A Fuse


17/115

at the same speed regardless of fault magnitude,while remaining completely selective.

Potential incident arc-flash energy can be furtherreduced by employing the instantaneous trip of themain and tie circuit breakers or fuses at the feeder

level. EntelliGuard circuit breakers are available withseries current-limiting fuses. Class L fuses rated at2000A and below are useful for limiting arc flashenergy in 480v systems. Class L fuses in feedercircuit breakers, rated above the circuit breakerslong-time trip setting but no larger than 2000A, canprovide significant reduction in incident energy for thehighest potential short-circuit current, while providingfair selectivity with smaller circuit breakers below.

The incident arc-flash energy plot in Figure 4.6shows a bus with a 4000A main and tie both oper-ated by a zone-based protection algorithm set topick up at 4000A with minimum time delay, a1600A feeder set at minimum time delay, a 2000Afuse and a 400A molded-case circuit breaker. Theincident-energy plot provides an indication of thecalculated incident arc-flash energy for the mainbus and feeder circuit. The incident-energy plotalso shows a 1600A fuse that could be used withan 800A switchgear feeder. The incident energyplot for a GE current-limiting Spectra circuit breakeris similar for all circuit breakers rated 600A and

below for prospective short-circuit currents of20kA and above.

In summary, Entellisys can provide fast protectionfor the main bus, limiting maximum HRC to level 3for systems rated up to 100kA IC at 480v. Feedercircuits can also be kept at HRC 3 or better withcomplete selectivity with downstream molded-casecircuit breakers at fault currents up to 65kA. Incombination with an instantaneous trip or fuses,it may be possible to achieve reasonably goodselectivity with downstream branch protectors while

keeping feeder circuit HRC to level 2 or lower forsystems rated up to 100kA IC at 480v.

Reduced Energy Let-Through (RELT) ModeWhen an operator is going to work near theequipment, it may be desirable to enable moresensitive protection settings to speed the detectiontime of a potential arcing fault. The operator canenable the RELT mode via the HMI which, whenlocated in Near Gear, can keep the operator out ofthe arc flash boundary.

When an Entellisys system has bus differential(87B) protection, the RELT mode provides a groupof settings that can differ from normal operatingsettings. Consequently, the zone-based protectioncan be set with a minimum time delay of 25ms. InRELT mode, it is also possible to have back-up

breakers designated to clear a fault, providinganother level of protection when someone isworking near live equipment.

When this mode is enabled, the RELT button onthe HMI is illuminated yellow, providing visual indication. An alarm may also be linked to this func-tion, providing additional visual indication as wellas email notification of this state. There are twoways to enable the RELT mode. The RELT settings can be turned on and off by a

simple touch on the screen by the operator. RELT can be controlled by a Virtual Output in

FlexLogic and thus initiated by the logic statesavailable in the system. When used in conjunc-tion with Discrete I/O, such scenarios as a prox-imity sensor, door status sensor, etc., can beused to enable and disable RELT.

The RELT state is also a protection element inFlexLogic and consequently can be turned on andoff via various logic states. It can also be linkedwith Discrete I/O to provide hardwired status to

other devices.

RELT changes of state are logged in the sequenceof events. When operators attempt to turn RELT oor off, the User ID is noted and action recorded. Italso is recorded when FlexLogic is issuing thecommands.

Multiple users can enable RELT at various timesover the same general time span. RELT will not becompletely disabled until the all of the users havedisabled their session.

When an operator is going to work on downstreamequipment, such as a low-voltage motor controlcenter, it may be advantageous to increase thesensitivity of the low-voltage switchgear feedercircuit breaker providing power to the MCC. Againby using the HMI settings screen for the particulacircuit breaker, the operator can shorten the delayof the feeder such as enabling instantaneousovercurrent protection providing increasedprotection during the maintenance time period.



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16

Circuit Breaker and Compartment Considerations

Closed-door OperationCircuit breaker compartment doors have no venti-lation openings, thus protecting operators fromhot ionized gases vented by the breaker duringcircuit interruption.

Wheels and GuidebarAll EntelliGuard circuit breakers are equipped withwheels and a guidebar to provide easy and accuratedrawout operation. When installing the breakers,they are lowered onto the extended drawout rails.Wheels on the side of the breaker allow the breakerto be easily rolled into the cubicle until the breakerengages the racking pins in the cubicle. The breakeris equipped with a rugged guidebar that ensuresprecise alignment of the primary and secondary

disconnects during insertion and withdrawal.

Closed-door DrawoutTrue closed-door drawout construction is standardwith all Entellisys equipment. The breaker compart-ment doors remain stationary and closed while thebreaker is racked out from the CONNECT position,through TEST, to the DISCONNECT position. Doorsare secured with rugged 1/4-turn latches.

Racking ToolIf a remote racking device is not used, a racking

tool may be used. This is a special drive wrenchwith a square 12 socket that engages the rackingmechanism on the breaker. One racking tool isused for all EntelliGuard circuit breakers.

Low-Voltage Power Circuit Breaker LockingAs a standard feature, the EntelliGuard low-voltagepower circuit breaker can be padlocked in theopen position with up to three 1/4 - 3/8 shankpadlocks to prevent unauthorized closing.

Breaker Insertion and Withdrawal Interlocks

Interlocks prevent racking the breaker in or outwhen the breaker contacts are closed. Circuitbreakers are trip free when not in the CONNECTor TEST position.

Defeatable Door InterlockThis option prevents inadvertent opening of thecompartment door unless the breaker is in theTEST or DISCONNECT position. A provision is madefor authorized defeat of the interlock.

Padlockable Door LatchThis optional feature enables padlocking of thedoor latch in order to prevent unauthorized entryinto the breaker compartment.

Drawout Padlock Provision

EntelliGuard and Entellisys offer an array of standard,safety locking features that provide extra measuresof security when breaker, equipment, or loadmaintenance is performed. In addition to the pad-locking feature on the breaker that keeps it open andtrip-free, EntelliGuard breakers are also equippedwith provisions to padlock them in either the TESTor DISCONNECT position. Furthermore, breakercubicles are furnished with padlocking provisionson the drawout rails to prevent unauthorizedinstallation of a breaker that has been removedfrom the cubicle for equipment or load maintenance.

This array of locking features should accommodateany type of lockout - tagout procedure a usermay have implemented at their facility. All of thepadlock provisions on EntelliGuard breakers andEntellisys equipment will accept any combination ofup to three padlocks with 14 to 38 diameter shank.

Key InterlocksThis option allows locking of the circuit breaker inthe open, trip-free position when fully connected.

Applicable schemes would be mechanical interlockingof two breakers so only one can be closed at atime or, in load center unit substations, interlockingof the primary switch and secondary main breakersuch that the secondary main must be open beforethe primary switch can be operated. Single anddouble key locks are available. Key locking doesnot prevent operation when the breaker is in theTEST or DISCONNECT position.

Network InterlockThe network interlock is a mechanical lockout

device optionally mounted on electrically operatedcircuit breakers. This is a logic driven interlock andis described in more detail in Section 5.

Breaker Position SwitchA breaker position switch is optionally available foruse in breaker control schemes. When supplied,the position switch will provide indication of thebreaker drawout position on the HMI breaker statusscreen. Descriptions of interlocking in automatic



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throwover schemes is discussed in more detail inSection 11.

Isolated Breaker CompartmentEach circuit breaker is located in a completelyenclosed ventilated compartment with grounded

steel barriers to minimize the possibility of faultcommunication between compartments.

Circuit Breaker Rejection FeatureA rejection system is provided as standard in eachbreaker compartment to prevent the insertion of abreaker with inadequate short circuit and/orincorrect continuous current ratings. EntelliGuardcircuit breakers of a larger frame rating may beplaced in a smaller frame rated compartment,provided they have similar dimensions. For example,a 2000A frame may be placed in an 800A framecompartment and a 4000A circuit breaker may beplaced in a 3200A compartment. Consequently itis possible to reduce the number of spare circuitbreakers required to have on hand.

Safety ShuttersSafety shutters protect operators from accidentalcontact with live conductors when the breakeris withdrawn. They are provided as a standardfeature on main and tie breakers in multi-sourcesubstations and are optionally available in all

other breaker compartments.

Equipment Considerations

Fully Tin-Plated Copper BusA fully tin-plated copper main and riser bus is astandard feature on Entellisys equipment. Tin platingprovides superior corrosion protection, especiallyfor application in the pulp and paper and wastetreatment industries where corrosive agentsroutinely exist. GEs bus bars are tin-plated afterforming and punching to ensure completely platedbolt holes and bar edges. Sliding contact surfaces,

such as breaker stab tips, are fully silver-plated.Fully silver-plated bus is available as an option.

Bus SystemBare bus is provided as standard on Entellisysswitchgear. In this configuration, there are no coversto remove, so all bus connections are easilyaccessible for maintenance. Note that a horizontal

isolation barrier is provided between the verticalbuses at every main and tie breaker for addedsafety in the event of a fault. An insulated/isolatedbus system that fully insulates the horizontal mainbus with a fluidized epoxy coating and isolateseach phase of the vertical riser bus is optionally

available. Accessibility to main bus joints is providedby replaceable covers, and no live connections arreachable from the rear except the breaker load sideterminals. Bus compartmentation is also available asan optional feature on Entellisys switchgear. Verticaand horizontal buses are isolated from the cablecompartment by glass reinforced polyester barriers

Infrared Scanning WindowsTwo types of infrared (IR) scanning windows areoptionally available in Entellisys for ease of thermascanning the power cables and terminations. Inbare bus construction it is also possible to scanbus joints. One type of window is an aluminummesh in an anodized aluminum housing with analuminum security cover. Also available is an IRcrystal that is transparent in the visible spectrumand it, too, has an aluminum security cover.


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18

Notes


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Entellisys Low-Voltage SwitchgearSection 5. EntelliGuard Breaker

The EntelliGuard circuit breaker is similar in construc-tion to the GE WavePro metal frame low-voltagepower circuit breaker, except the EntelliGuard breakerhas no trip unit or current sensors. EntelliGuardbreakers are ANSI-tested, UL Listed, and designed

to withstand short circuit stresses equal to theirshort time interrupting ratings. This allows maximumselectivity with downstream devices when shorttime tripping characteristics are used. They includea closed-door drawout mechanism that is used tomove the breaker from the DISCONNECT to theCONNECT position. The drawout mechanism canbe operated manually at the front of the cubicle,or a remote racking device can be attached to thebreaker for electrically racking the breaker throughits drawout positions. Remote racking can be operat-ed from up to 30 feet from the front of the switchgear

line-up, providing an extra measure of safetybetween the operator and the energized equipment.

EntelliGuard breakers can be supplied in one of twoforms manually operated or electrically operated.Manually operated breakers are provided with aflush-mounted manual spring charging handle andmechanical CLOSE and OPEN buttons on the frontof the breaker escutcheon. Electrically operatedbreakers are supplied with the same manual chargingmechanism and mechanical CLOSE / OPEN buttons,but are also equipped with a 120v AC spring charging

motor, close coil with anti-pump circuit, and shunttrip coil. The manual charging handle and theOPEN / CLOSE push buttons are double insulatedfrom live components to provide additional operator

safety. Entellisys can close, open, and trip anelectrically operated breaker. Manually operatedbreakers can only be tripped by Entellisys.

All EntelliGuard breakers have front-mounted indica

tors for breaker drawout position (CONNECT / TEST /DISCONNECT) and closing spring status (CHARGED DISCHARGED). Standard padlock provisions, for upto 3 padlocks, are supplied on all breakers as ameans to prevent unauthorized or accidentalbreaker closing during maintenance operations.

AccessoriesAccessories for the EntelliGuard breaker are limitedto a bell alarm with lockout and network interlockAll other functions for breaker control and monitorinare part of Entellisys and are enabled via software

The bell alarm with lockout operates whenever anovercurrent protective function trips the circuitbreaker. This device will mechanically lock out thecircuit breaker and is reset manually via a resetbutton on the front of the breaker escutcheon. Thbell alarm can also be programmed to operateand lockout the circuit breaker for any or all of theprotective relay options provided by Entellisys.

The network interlock is also a mechanical lockoudevice mounted on the circuit breaker. It is a logic

driven interlock and has two states SET (LOCKOUTand RESET. Setting the Network Interlock to LOCKOUTwhen the breaker is closed will cause the breakerto trip. In the LOCKOUT position, the Network

Figure 5.1EntelliGuard Breaker

Padlock Provisions

Open/Close Pushbuttons

Catalog #/Rating Nameplate

Manual Charging Handle

Indicators For Drawout Position Spring Charge Contact Position

Remote Close/One

Shot Electronic Close

Spring Charge

Indicator Switch

Network Interlock

Shunt Trip

Secondary Disconnect

Auxiliary Switch

Spring Charging Motor

Bell Alarm With

Target/Reset Button


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20

Interlock holds the breaker mechanically trip freeand also inhibits electrical closing. The control logicin Entellisys must provide a command to reset theNetwork Interlock before the breaker can be closedmanually or by control logic. Loss of control powerwill not cause the Network Interlock to reset.

Discussions of other components associated withthe EntelliGuard breaker and cubicle follow.

Auxiliary SwitchThe auxiliary switch contacts are used for indicationof the breaker main contact position. An auxiliaryswitch is provided on all manually and electricallyoperated breakers. Auxiliary contacts are connectedto the Messenger and provide breaker status inputto the CPUs and to the Breaker Status screen on theHMI. The same auxiliary contacts also control the redand green LEDs on the front panel of the Messenger.

Fans and Fan ControllerThe EG-50 (5000 amp) breaker is provided withintegrally mounted cooling fans. Fan operation iscontrolled by the Messenger, which turns the fanson and off when the load current exceeds or dropsbelow 4200 amperes. The switchgear controlpower transformer provides 120v AC control powerfor the fans. Power requirement for each fan is0.2amps @ 120v AC (two fans installed).

Fuse Roll-out or Fuse CarriageA fuse roll-out is used in conjunction with EntelliGuardbreakers that are not integrally fused and areapplied in high available short circuit current systems.The fuse roll-out is equipped with wiring and asecondary disconnect for blown fuse sensing. Thesensing wiring is connected to the breaker-mountedOpen Fuse Lockout (OFLO). The OFLO trips the circuitbreaker whenever a fuse in the roll-out opens dueto short circuit current interruption. EntelliGuardbreakers type EGF-20, 32, 40 and 50 are supplied

with the open fuse lockout. Key interlocking isrequired for both the circuit breaker and fuse roll-outto prevent removal or insertion of the fuse roll-outunless the circuit breaker is open.

Hidden Close ButtonThe Hidden Close button is provided on electricallyoperated EntelliGuard breakers when equippedwith a Network Interlock. The Hidden Close buttonreplaces the standard manual close button in thebreaker escutcheon but provides limited access to

the mechanical close mechanism for emergency orsupervised operation. A 0.100 diameter rod can beinserted through a hole in the Hidden Close buttonto manually close the breaker provided the NetworkInterlock is in the RESET position. The Hidden Closefeature provides double insulation between the

operator and any live parts in the breaker. Thecombination Hidden Close Button and NetworkInterlock is used on circuit breakers that traditionallywould be electrically interlocked with other circuitbreakers, such as in automatic transfer schemes.

Key InterlocksOptional provisions for a key interlock are locatedon the left side of the breaker cubicle. Key interlocksare used to supervise the closing of a circuit breakeror the operation of upstream or downstreamdevices. Typical applications include interlockingmain and tie circuit breakers to prevent parallelingand interlocking secondary main breakers withprimary air switches. Breakers can be locked in theopen position only. Normally, the key is removablewhen the lock bolt is extended, holding the breakerin a trip-free condition. Certain key interlockapplications require the key to be removablewhen the breaker can be closed or when the lockbolt is withdrawn. Up to two key positions can beaccommodated in each breaker cubicle.

Open Fuse Lockout (OFLO)The open fuse lockout device is provided with anyfused (EGF) EntelliGuard circuit breaker. The OFLOconsists of an individual trip solenoid and targetindicator for each circuit breaker pole, connecteddirectly across the fuse in that phase. When anyfuse blows, the solenoid is energized and trips thecircuit breaker to prevent single-phasing. TheEntelliGuard breaker is mechanically locked outand cannot be reclosed until the fuse is replacedand the target indicator on the OFLO is reset.

When the current limiting fuses are mounted in aseparate fuse roll-out, as with EGF-20, EGF-32,EGF-40, and EGF-50 circuit breakers, the openfuse lockout is wired to the fuses throughsecondary disconnects on the fuse roll-out andon the circuit breaker.

Position Switch (By-Pass Switch or TOC Truck-Operated-Contact)This optional accessory is mounted in theEntelliGuard breaker cubicle and is supplied with one

Section 5. EntelliGuard Breaker


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normally open and one normally closed contact.The position switch is used to indicate the drawoutposition of the breaker, and the switch contactschange state when the breaker is moved betweenthe CONNECT and the TEST positions. The twocontacts on the position switch are wired to the

Messenger in the breaker cubicle and providebreaker drawout position indication on the BreakerStatus screen at the HMI. They can also be used inany Flex Logic control scheme.

Spring Charge Indicator SwitchThe spring charge indicator switch is provided onall electrically operated EntelliGuard circuit breakersand is wired to the Messenger. This contact providesstatus of the circuit breaker closing springs on theBreaker Status screen at the HMI and can also beused in Flex Logic control schemes.

Remote Close Accessory with One-ShotElectronic Close CircuitThe remote close accessory is an electricallyoperated solenoid which, when energized throughthe HMI or a Flex Logic control scheme, closes theEntelliGuard circuit breaker. The remote closeaccessory consists of the one-shot electronicclose circuit, with built-in anti-pump feature, andthe closing solenoid. The remote close accessoryis continuously rated and operates as follows.

Applying control voltage to the close circuit throughthe Messenger produces a 250ms pulse to theclosing coil which, in turn, releases the energy storedin the closing springs. The anti-pump feature preventsthe breaker from repeatedly closing if the closesignal is maintained. The Messenger provides amomentary close signal (12 second duration)whenever the HMI or Flex Logic issues a closecommand. Reset time for the anti-pump circuit isapproximately 2.5 seconds.

Secondary DisconnectAll EntelliGuard breakers are furnished in drawoutconstruction. The interface between the breaker andthe Entellisys system occurs through a rugged,36-point secondary disconnect mounted on thetop of the circuit breaker. The secondary disconnectis engaged when the breaker is in the CONNECT andTEST positions and is disengaged when the breakeris in the DISCONNECT position. A feedback mecha-nism is provided on the secondary disconnect toconfirm to Entellisys that the secondary disconnect

is properly engaged. Status of the secondarydisconnect (Connected or Disconnected) is shownon the Breaker Status screen at the HMI.

Shunt TripThe shunt trip allows remote electrical opening of

the EntelliGuard circuit breaker through the HMIand Flex Logic. The shunt trip is supplied on allelectrically operated breakers and is not availableon manually operated breakers. The shunt trip cois rated for intermittent duty and is supplied withan auxiliary switch contact that automaticallyremoves control power from the coil when thebreaker opens.

Spring Charging MotorThe spring charging motor is supplied on all elec-trically operated EntelliGuard circuit breakers. Thebreaker closing springs are charged automaticallywhen control voltage is applied to the breaker. Thitypically occurs when the breaker is racked in tothe cubicle and the secondary disconnect engagesWhen the breaker closing springs are fully chargeda cutoff switch de-energizes the charging motor.The closing springs will recharge automaticallyafter a breaker closing operation. If control poweris lost during the spring charging cycle, springcharging can be completed using the integralmanual pump handle.

RatingsThe EntelliGuard breaker is available in 800, 1600,2000, 3200, 4000, and 5000 amp frame sizes withshort circuit interrupting ratings from 30kA to 200kAThe model number of the breaker indicates itsinterrupting capacity (IC). EGS indicates StandardIC, EGH indicates High IC, EGX indicates ExtendedIC, and EGF indicates Fused.

High IC and Extended IC breakers are used withlarger kVA substation transformers as well as in

paralleling applications. Fused circuit breakers havea 200kA IC rating for use in large network systems.

Table 5.1 lists the interrupting capacities (IC) forEntelliGuard breakers at system operating voltages

Catalog NumbersA unique catalog number identifies all EntelliGuardbreakers. The catalog number contains informationon the breaker frame rating (continuous currentand short circuit), the fuse rating (if equipped with


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22

Figure 5.2EntelliGuard Low-Voltage Power Circuit Breaker Catalog Numbers

EG 1 A 1 N XX

EntelliGuard Breaker Suffix

Unused

Interrupting Capability / Fuse Type

1 = Standard (EGS) Accessory

2 = High (EGH) X = None

3 = Extended (EGX) B = Bell Alarm w/ Lockout

4 = OFLO only N = Network Interlock (includes

(Fuses for EGF-08 / 16) Hidden ON Button) E/O only

A = 300A Class J fuse

B = 350A Class J fuse

C = 400A Class J fuse Operation

D = 450A Class J fuse X = Manual

E = 500A Class J fuse 1 = Electrically operated

F = 600A Class J fuse (120vAC Charge, Close, Trip)

G = 800A Class L fuse

H = 1000A Class L fuse Frame Size

J = 1200A Class L fuse A = 800A

K = 1600A Class L fuse E = 1600A

L = 2000A Class L fuse H = 2000A

M = 2500A Class L fuse (Silver fuse) K = 3200A

N = 800A Welder Limiter M = 4000A

Q = 1600A Welder Limiter P = 5000A

R = 2000A Welder Limiter

Refer to Table 5.2 for allowable fuse, sensor, and trip ratings for EGF-08 / 16 breakers

Table 5.1EntelliGuard LVPCB Interrupting Capacity

EGS Standard Interrupting EGH High InterruptingEGX Extended Interrupting EGF Fused1 (200kA IC, 600v max)

1 800 & 1600A frame breakers are integrally fused. Larger frame breakers(2000 - 5000A) require a separate fuse roll-out for 200kA IC rating.

Rated AC

Voltage,Nominal(max)

BreakerType

Frame

Size(amps)

Short Circuit Interrupting Capacity,RMS Symmetrical kA

Short-TimeWithstand

WithInstantaneous Trip

WithoutInstantaneous Trip

600 (635)

EGS-08

800

30 30 30

EGH-08 42 42 42

EGX-08 50 50 50

EGS-161600

42 42 42

EGH-16 65 65 65

EGS-20 2000 65 65 65

EGS-32

3200

65 65 65

EGH-32 85 85 85

EGX-32 85 85 85

EGS-404000

85 85 85

EGX-40 85 85 85

EGS-505000

85 85 85

EGX-50 85 85 85

480 (508)

EGS-08

800

30 30 30

EGH-08 42 42 42EGX-08 65 65 65

EGS-161600

50 50 50

EGH-16 65 65 65

EGS-20 2000 65 65 65

EGS-32

3200

65 65 65

EGH-32 85 85 85

EGX-32 100 100 100

EGS-404000

85 85 85

EGX-40 100 100 100

EGS-505000

85 85 85

EGX-50 a 100 100

240 (254)

EGS-08

800

30 42 30

EGH-08 42 50 42

EGX-08 65 65 65

EGS-16

1600

50 65 50

EGH-16 65 65 65EGS-20 2000 65 65 65

EGS-32

3200

65 85 65

EGH-32 85 130 85

EGX-32 100 130 100

EGS-404000

85 130 85

EGX-40 100 130 100

EGS-505000

85 130 85

EGX-50 100 130 100

600 (600) EGF-xx ALL 200 200

current limiting fuses), operation (manual or electrical),and accessories. Figure 5.2 provides the developmentof EntelliGuard breaker catalog numbers.

Wiring DiagramFigure 5.3 shows the wiring for all standard

EntelliGuard circuit breakers. All breakers includean auxiliary switch and flux shift trip coil.

Electrically operated breakers include springcharging motor, close coil with anti-pump circuit,shunt trip, and remote charge indicator switch.Cooling fans are supplied only on 5000A EntelliGuardbreakers. Bell alarm with lockout is an option forboth manually and electrically operate breakers.

Network interlock is an option for electricallyoperated breakers only.



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Figure 5.3Wiring Diagram



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24


Table 5.2Allowable Current Limiting Fuse Sizes for EntelliGuard Breakers

* These fuse sizes are also available as Welder Limiters.1 Class L fuses less than 800A are not UL or CSA listed. Use Class J fuses for 600A

and below. The maximum fuse rating is the largest fuse that tests show will result

in proper performance of the breaker and fuse in combination under short-circuit

conditions. Only Ferraz-Shawmut fuses should be used for proper coordination.2 Fuses are mounted in a separate roll-out element (fuses shipped as XS material).3 Integrally fused 1600A frame breakers (EGF-16) equipped with 2500A fuses can be

furnished with rating plugs from 300 1600A. Breakers equipped with 2500A fuses

cannot be modified to accept lower rated fuses. EGF-16 breakers equipped with

2000A and lower fuses cannot be upgraded to 2500A fuses. The maximum trip

rating for an EGF-16 breaker is 1200A when furnished with other than 2500A fuses

(see table for min/max fuse rating for each rating plug value). 2500A fuses preclude

the use of shutters in the breaker cubicle.

BreakerType

FrameSize

SensorRating

Messenger CurrentSetting Switch Ferraz-Shawmut Fuse Range

1

EGF-08 800A

150A

400A

800A

Below 150A

300/350/400/450/500/600/

800*/1000*/1200*/1600*A

150A

225A300A

400A400/450/500/600/800*/1000*/

1200/1600*A

600A 600/800*/1000*/1200/1600*A

700A 800*/1000*/1200/1600*A

800A 1000*/1200/1600*A

EGF-16 1600A

800A

1600A

400A and below450/500/600/800*/1000*/1200/

1600*/2000*/2500A3

500A500/600/800*/1000*/1200/

1600*/2000*/2500A3

600A600/800*/1000*/1200/1600*/

2000*/2500A3

700A 800*/1000*/1200/1600*/

2000*/2500A3800A

1000A 1000*/1200/1600*/2000*/2500A3

1200A 1600*/2000*/2500A3

1600A 2500A3

EGS-202 2000A 2000A 2000A and below 2000/2500A

EGS-322 3200A 3200A 3200A and below 2000/2500/3000/4000A

EGS-402 4000A 4000A 4000A and below2000/2500/3000/4000/5000A

EGS-502 5000A 5000A 5000A and below


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26

Section 6. EntelliGuard Messenger

directly into a Messengers A/D converter via theTest Port connector. The test kit can change thewaveform characteristics of the sinusoidal signalsto test the different overcurrent and protectiverelay functions for each circuit breaker.

Sealable CoverA hinged, clear Lexan cover is installed over theLEDs, switches, and Test Port. The cover includesprovisions for wire seals so that the current settingand long time pick-up selections can sealed tomeet the requirements of NEC for restrictedaccess to the trip setting adjustments.

Self-Powered ModeThe Messenger is normally powered from theswitchgear redundant control power buses withdual UPS back-up. In this operating mode, theMessenger passes digital signals of the currents andvoltages to the dual CPUs and, in turn, receives andexecutes instructions from the CPUs if the currentsand/or voltages require a breaker operation.

The Messenger provides overcurrent protection forthe circuit in the event all control power is lost(loss of both control power sources and bothback-up UPSs) or both redundant communicationnetworks or redundant CPUs become unavailable.The Messengers self-powered mode utilizes power

from the cubicle-mounted current sensors topower its internal circuits. When running in self-powered mode, the overcurrent protection curvesbuilt in to the Messenger utilize the maximumpick-up and delay settings for each applicableovercurrent function (overload, short circuit, andground fault). Using the maximum pick-up anddelay settings insures the self-powered overcurrentcharacteristics in the Messenger will not interfere

with the programmed settings running in the CPUs.

Compared to traditional low voltage circuit protection,the self-powered mode is similar to having aback-up integral trip unit on a circuit breaker thatis programmed with all overcurrent characteristics

set at their maximum values.

i-ButtonA factory-programmed memory device calledthe i-Button provides the unique protectioncharacteristics for each breaker cubicle in theswitchgear line-up. Characteristics include thebreaker frame size, the installed current sensorrating, and the overcurrent characteristics forthe circuit. The i-Button programming determinesthe upper and lower limits for the overcurrentprotection settings and the type of ground faultprotection (none, standard, or switchable).

The i-Button and holder are tethered to the breakercubicle and communicate with the Messenger viaa slot in the side of the Messenger. Now, the uniquecharacteristics of a given circuit are captured inthe i-Button, which becomes a part of the breakercubicle and therefore a part of the connected load.

The i-Button Messenger EntelliGuard breakerconcept of Entellisys simplifies the task of determining

component interchangeability and the quantity andtype of spare parts to have on hand. All EntelliGuardMessengers are identical; therefore, only one catalognumber is required for spare parts stocking. AllEntelliGuard breakers for a given frame size andfunction are identical, thus requiring fewer sparebreakers for the range of loads in a plant. Componentinterchangeability and reduced spare parts is oneof the recognizable benefits of the Entellisys concept.

Table 6.1Current Sensor Values and Associated Current Settings

Current SensorRating (Amps)

Current Setting(Amps)







150

80

800

300

2000

750

4000

1600100 400 800 2000125 450 1000 2500150 500 1200 3000

400

150 600 1500 3200200 700 1600 3600225 800 2000 4000250

1600

600

3200

12005000

3200300 800 1600 4000400 1000 2000 5000

1100 24001200 25001600 3000

3200


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Entellisys Low-Voltage SwitchgearSection 7. Protection

Entellisys low-voltage switchgear offers a broadarray of familiar and expanded protection capabili-ties. All modes of protection except high-resistanceground-fault detection are available from everyCPU without additional hardware. If your Entellisysequipment does not have the type of protection

enabled that your power distribution system needsnow, it can probably be easily added.

The Entellisys centralized single-processor systemprovides backup protection at the individual circuitbreaker level. It offers overcurrent protection usingtraditional inverse-time characteristics, plus single-point relay protection, such as under- andovervoltage protection. All of this protection isprovided by two CPUs, each providing redundantback-up to the other at all times. In addition, moreredundant overcurrent protection is provided at theindividual circuit breaker level by the Messengerassociated with each circuit.

However, the Entellisys system offers much morethan these traditional protection modes. Its abilityto simultaneously consider all the voltages, currents,and circuit breaker conditions within the systemprovides zone-based protection and optimization ofprotective settings for a variety of situations. Thisincludes changes in the topology or number ofsources available, changes in load demand, and even

changes in factors external to the gear that are com-municated via the Entellisys systems Modbus overTCP/IP interface or Discrete I/O capability.

The result is selective protection for a wide rangeof fault values by delivering fast circuit interruptionwhen needed, while shutting down only those

circuits that absolutely must be shut down.Maximum system reliability, lower fault energy letthrough, and lower arc flash energy can all beachieved simultaneously. Minimum let-throughand minimum arc flash energy can be obtainedvia quick settings when needed most.

This section describes the protective capabilitiesprovided by Entellisys. Further detail is providedby various referenced GE publications thatdescribe specific functions in more detail. Settingup and defining the exact protective levels you needare described in the appropriate GE Entellisysinstruction book.

Traditional Overcurrent Protection

Broad range of settings

Each circuit breaker cubicle contains a set of currentransformers (CTs) that provide the current signalsfor all overcurrent, relay, and metering functions.The Entellisys system needs no additional CTs. Forcircuit breaker frames rated at 2000 amperes andabove, the CTs are sized to the circuit breaker frameSmaller frames may have one of several CTsas listed in Table 7.1. All protective settings foreach circuit breaker depend on the CTs in thecorresponding cubicle.

The long-time pickup for each circuit breaker is se

at the Messenger above each circuit breaker. Therest of the protective settings for each circuitreside in software at each of the redundantEntellisys system central processor units (CPUs).The settings may be adjusted via the human-machine interface (HMI) for the system. Theexception to this is the instantaneous trip setting

Table 7.1Current Sensors and Current Switch Settings Available forEach CB Frame

Rating switch and CT rating is set at the Messenger.

Frame Size Sensors Rating Switch Values in Amperes

800

150 80, 100, 125, 150

400 150, 200, 225, 250, 300, 400

800 300, 400, 450, 500, 600, 700, 800

1600800 300, 400, 450, 500, 600, 700, 800

1600 600, 800, 1000, 1100,1200, 1600

2000 2000 750, 800, 1000, 1200, 1500, 1600, 2000

3200 3200 1200, 1600, 2000, 2400, 2500, 3000, 3200

4000 4000 1600, 2000, 2500, 3000, 3200, 3600, 4000

5000 5000 3200, 4000, 5000


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28

that is made at the HMI and communicated to theEntellisys Messenger, where it is resident until theCPU communicates a different setting.The following is a list of the single-breaker over-current protection functions available: Long-time pickup (set at Messenger)

Four long-time delay bands (set via HMI) Short-time (selectable and set at HMI)

I2T slope in or out (selectable at HMI) Seven short-time delay bands (set via HMI)

Ground fault (optional) (settable at HMI) I2T slope in or out (selectable via HMI) Seven ground-fault delay bands (set via HMI) Available from factory with GF protection, without

GF protection or with selectable GF protection Adjustable instantaneous (selectable and

adjustable via HMI) Backup protective function for each CB (set at

Messenger via long-time pickup setting)

The nominal setting values and available currenttransformers are listed in Tables 7.1-7.8.

Time-delay bands for short-time andground-fault protectionThe Entellisys system provides seven time-delaybands for both short-time and ground-fault functions.The minimum time-delay bands for both short-timeand ground-fault protection allow the protection

algorithm to sense and initiate a trip as quickly as1.5 cycles, corresponding to 25 ms for 60 Hz or 30ms for 50 Hz systems. This allows circuit breakersto clear in less than six cycles, regardless of faultmagnitude, while being selective with molded-casecircuit breakers that may be connected downstream

of the switchgear feeder. The time-delay bandsfor EntelliGuard circuit breakers are selective withany molded-case circuit breaker that is able toclear in one cycle or less.

Heating and cooling algorithmThe long-time, short-time, and ground-faultprotection functions are provided with an algorithmthat accounts for the heating and cooling effectsof intermittent high currents. A counter is startedwhen the long-time function is engaged. If the circuitcurrent falls below the threshold, the long-timefunction is no longer in pickup and the counter startsdecrementing. If the current level increases to againengage the long-time pickup, the counter resumesincrementing from its present count. This protectsagainst the potentially harmful effects of cyclinghigh loads that slowly build up heat in conductors.

Instantaneous settingWhen provided, instantaneous protection residesat the Entellisys Messenger, but is set via the HMI.The adjustment range for instantaneous protection

Section 7. Protection

Table 7.2

Long Time Pick Up

LTPU determined by setting switch and rating switch position.Both are located and set at the Messenger.

Set at .5 to 1.1 of rating switch value

Long Time Pick Up band centered at nominal current value 10%

Table 7.4

Short Time Pick Up

Short time pick up is set at the CPU via the HMI.

Set at 1.5 to 9 of Long Time Pick Up value

Short Time Pick Up band centered at nominal current value 10%

Table 7.3Long Time Delay Bands

This time represents the nominal pick up time for the bandand excludes circuit breaker clearing time. The trip-time band widthin the time scale is +20% to account for circuit breaker clearing timeand CT sensing accuracy. Refer to the time current curve.

Long TimeDelay Bands

Nominal Time at which Time Delay BandsIntersect the Long Time Pick Up Band

Band 1 108 seconds

Band 2 216 seconds

Band 3 432 seconds

Band 4 900 seconds

Table 7.5Short Time Delay Bands (Milliseconds)

Where the I2T band is enabled, the slope of the band shall be an I2T =K slope.Where K = 18 and I = (C x IRMS) = Rating Switch x Setting Switch x IRMS.The I2T slope shall extend from the short time pick up band to the time delayband selected. Refer to the time current curve.

Band 60 Hz 50 HzPU Clear PU Clear

1 25 92 30 902 58 158 60 1603 100 200 100 2004 167 267 170 2705 217 317 220 3206 283 383 280 3807 400 500 400 500


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Table 7.6

Instantaneous Pick Up Settings

Setting is a multiple of the Setting Switch Value. Minimum instantaneoussetting is 1.5. Settable in increments of .5. Instantaneous is set via the HMIbut it is resident at the Messenger and the instantaneous trip is calculatedat the Messenger independent of activity at the CPU.

Circuit BreakerFrame Size

Maximum Instantaneous SettingShort-Time Enabled Short-Time Not Enabled

800 15 101600 15 102000 15 103200 13 104000 9 95000 7 7

Table 7.8

Ground Fault Delay Bands (Milliseconds)

Where the I2T band is enabled, the slope of the band shall be an I2T =K slope.Where K = 2? and I = (GFPU x IGFRMS) = Ground Fault Pick Up x CT rating xGround fault current. The I2T slope shall extend from the short time pick upband to the time delay band selected. Refer to the time current curve.

Band60 Hz 50 Hz

PU Clear PU Clear

1 25 92 30 902 58 158 60 1603 100 200 100 2004 167 267 170 2705 217 317 220 3206 283 383 280 3807 400 500 400 500

Table 7.7Ground Fault Pick Up

Pick up setting is times current sensor rating. Setting increments are 0.01.

Sensor Pick up setting range

150-2000 0.2 - 0.60

3200 0.2 - 0.37

4000 0.2 - 0.30

5000 0.2 - 0.24

depends on the size of the circuit breaker andwhether or not the circuit breaker is provided withthe short-time function. Once set, instantaneousprotection does not depend on the continuingoperation of the CPU or the communication system.Table 7.6 lists the available instantaneous settings.

If the switchgear is started from a blackout conditionwith a circuit breaker closed, the Entelliguard circuitbreaker with instantaneous trip has built-in backupinstantaneous protection set at 1.7 times the max-imum short-time setting of the circuit breaker. Untilthe CPU downloads a user-defined setting to theMessenger, this fixed rating provides a safety backup.As soon as the CPU communicates a setting to theMessenger, the new user-defined setting takes over.

Entelliguard circuit breakers have no making-currentrelease or hidden instantaneous. Except for a blackstart condition as described in the preceding para-graph, the circuit breakers have sufficient close andlatch ratings to be equally selective upon closing in ona fault as they do during normal power-on conditions.

Long-time, short-time and ground-fault settingsEach Entelliguard circuit breaker is provided with anadjustable long-time characteristic, an instantaneousand a short time response. Each circuit breaker mustbe set with either short time, instantaneous, or both.

Ground-fault detection or ground-fault tripping isa factory option. User selectable ground fault protection (Switchable Ground Fault) is also availablebut may affect the equipment UL label.

When ground-fault protection (tripping) is provided,

the function will have separate Trip and Alarm settings capabilities. Like other single point relays, thtrip and alarm functions are separately adjustableand independent of each other. The settings rangesfor Alarm are the same as those for Trip. The groundfault alarm function associated with ground-faultprotection can be enabled or disabled. A selec-table and adjustable ground fault alarm functionis always provided for each circuit breaker, at theHMI, regardless of the ground fault protectionoptions that are selected for the circuit breaker.Available settings for the various overcurrentprotective functions are described in Tables 7.2-7.8

Backup protectionEach Entellisys Messenger is provided with self-powered backup protection that protects the powecircuit breaker if proper communication to the CPUis lost or if the CPU does not issue the requiredprotection commands. Backup protection consistsof long-time pickup that is set with an adjustmentswitch on the front of the node. Fixed nonadjustablelong-time delays, short-time pickup and delay, and


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Table 7.10

Double-ended Substation Topologies

1 Topology 0 is used for unpowered buses and may be used for maintenance purposes.2 Topology 1 is used when the zone is powered from Main 1.3 Topology 2 is used when the zone is powered

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