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M P R 3 0 0
ApplicationsMPR 300 Motor protection relay is suitablefor back
panel surface mounting or DIN railmounting. It offers multiple
protections to 3phase induction motors. The R-Y-B phasewires of the
motor passes through the relay(no need for external Cts).The
measurements are carried out throughintegral CTs and electronics
built inside therelay. One set of trip contacts (1 N/O + 1N/C) is
available for trip functions along withindividual LED indications.
The relay is
ideally suitable for protection of motorscoupled to pumps,
compressors, fans,ventilators, cranes, elevators, escalators,saw
mills, paper mills, motorized valves,conveyor belts etc. where
frequent over loads, rotor stalling, faulty bearings, and
dryrunning conditions are expected.
PROTECTIONS
a) Thermal over load protection :b) Negative sequence
protectionc) Earth Fault protection
d) Locked rotor protectione) Under current protection
Each of the above faults are indicated by aLED on the front
panel. On occurrence of fault, the relay provides two contacts 1
N/Oand 1 N/C. These contacts are manual resetand can be used to
open a contactor. TheLED fault indication is manual reset
onclearance of the fault, the LED has to bereset by the front panel
Reset PB.
TECHNOLOGYMPR 300 uses state of the art digitaltechnology to
measure the three phaseand residual currents in the motor
feeder.The current signals are sensed throughinbuilt CTs and
evaluated bymicrocontroller using advanced digitalsampling
techniques. Special algorithmsare used for deriving the thermal
statusand other parameters required for variousprotections. The
hardware design provideshigh degree of accuracy and reliability.The
relay comes in 6 different models tocover full range of motor rated
currentsstarting from 1A to 88A. In addition tooffering important
protections, the relay ismost user friendly, simple to
withstandhigh level of EMI/EMC interferences whichare increasingly
present in the present dayindustrial environment.
Compact Microcontroller based
design 6 models to cover motor
rated currents upto 88A 5 protections 3 integral Cts DIP switch
selection for
Thermal Characteristics Trip indication Test funct ion
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TECHNICAL SPECIFICATIONS
Input Connection R-Y-B wires of motor passes through relayBasic
Protections Thermal Over load, Negative Sequence (Phase
Unbalance)
Locked Rotor, Earth Fault and Under Current
Thermal Over Load Protecti on
1. Current setting 1 to 88A in 6 different models as follow s :1
to 2.75A 2 to 5.50A 4 to 11A8 to 22A 16 to 44A 32 to 88A
2. Trip Time Characteristics Class 10A, 10, 20 and 30 as per LEC
947-4-1Field selectable through front DIP switches.
3. Pre alarmAt 1.05 lm by flashing LED (lm = Motor rated
current)4. Thermal MemoryProvided.
Earth Fault Protecti on1. Current setting 10 to 50% of Im field
selectable by front panel pot.2. Trip time delay 200 msec factory
set3. Disable feature Available from front panel pot.
Phase Unbalance Protecti on1. Unbalance current 50% of Im
factory set2. Trip time delay 3 sec factory set
Locked Rotor Protection1. Locked rotor current3 Im factory set2.
Trip time delay 1sec factory set3. Disable featureAvailable from
front panel DIP switch
Under Current Protection1. Under current threshold50% of Im
factory set2. Trip time delay3 sec factory set3. Disable
featureAvailable from front panel DIP switch
Operation al IndicatorsLED indications for Power OnLED
indications for trip on each of the 5 faultsLED starts flashing
when fault is detected. Becomes steady onWhen the relay trips after
the preset time delay.LEDs are manual reset.
Contacts 1 N/O + 1 N/C manual resetRated Voltage 250 V AC / 30 V
DCRated Current 5ARated breaking capacity 2000 VA / 240 W
(resistive)
Auxi li ary Power Supply 240 V AC +/- 20%
Operating Temperature 0 to 60 degrees C Accurac y As per IEC
947-4-1Reset Current 95% to 90% of ImReset Time Less than 160
millisec for O/L, N/S, U/C and L/R faults
Less than 80 milisec for Earth faultReference Standards IEC
60255, IEC 61000 and IEC 60068
TRIPCLASS Tripping Time at multiple of Ie
10A102030
120%> 2 hours> 2 hours> 2 hours> 2 hours
150%2min4min6min12min
720%2-10 sec.4-10 sec.6-20 sec.9-30 sec.
