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TECHNICAL SPECIFICATION II

TECHNICAL SPECIFICATIONS:

I. General :

The Battery charger shall comprise of thyristor controlled float-cum-boostcharger equipped with quality filter for ripple suppression along with allassociated hardware and housed in a single floor mounted steel cabinet. Theequipment should be well ventilated and suitable for floor mounting with hingeddoor at front and rear sides. Cable entry holes shall be provided at both front andrear sides of bottom plate. The charger shall work in conjunction with 24 nos.

plante type cells, each of 2 volts which constitute 48V/ 300 AH capacity Batterysets. The charger unit shall be capable of delivering requisite current under float,quick and boost condition as may be necessary for the battery to keep it healthyin the useful life and in the manner as specified by the Battery manufacturer atvarying voltages to meet the requirement of battery charging characteristics.Constant current charging of the battery sets shall be the essence of initialcharging while setting to service in order to ensure feeding of specified Ampere-hour to the battery sets being commissioned. Modular construction to incorporatethe desired features to define the individual functions as specified hereunder isdesired.

High galvanic insulation level should be maintained. Insulation resistance

measured between Earth and input/ output terminals and between input andoutput terminals shall not be less than 2 Meg-ohms when measured with 500VD.C. insulation tester.

The Float-cum-Boost charger shall be able to charge the battery maintainingacross the equipment a voltage of 48V (+10%, -5%) DC or maintain a voltage toreach a maximum of 2.3V per cell under float conditions and offer to the load thespecified voltage.

The quick and boost charging mode should ensure that the load is fed with itsrated voltage only by means of dropper diodes.

II. Design requirement:-

Float-cum-Boost charger for 48V/ 300 AH Plante Lead Acid Battery set shallfulfill following design requirements:-

i) The equipment shall have 3-phase full wave rectifier bridge employing diodesand thyristors at the secondary side of the transformer for regulation of outputvoltage.

ii) Single phasing trip with indication and alarm shall be provided at the inputsupply side of the equipment. There shall be facility for auto switching ON of thecharger when 3 phase supply is restored.

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iii) The Battery Charger shall have following output DC voltages in float, quick andBoost mode :a) Battery Voltage at Float Mode = 48V 55.2V DC adjustable.b) Battery Voltage at Quick Mode = 55.2V 56.4V DC adjustable.c) Battery Voltage at Boost Mode = 56.4V 66V DC adjustable.

iv) Charge current control with soft start and overshoot protection feature should beincorporated.

v) Output current of the charger unit shall be capable of continuously adjustablethroughout the entire range.

vi) There should be an error amplifier card in the charger to facilitate constantcurrent charging. Total current shall be kept limited so as not to exceed the ratedcurrent limit of the unit.

vii) DC load over voltage protection with annunciation and tripping facility shall be

incorporated.viii) Battery under voltage indication with alarm at 1.85 volt per cell and load autodisconnect feature at 1.75 volt per cell shall be provided. The auto loaddisconnect facility shall have auto reset and manual reset options. Auto reset willtake place when battery gets charged upto 2.2 volts per cell. Provisions foradjustment of levels of these voltages shall be provided.

ix) There should be individual voltage sensor card in the charger to monitor batteryvoltage & bring in dropper diode bank automatically to keep load voltage withinlimit.

x) In auto mode the equipment shall monitor float current drawn by the battery, andif the float current is more than 10-15 times the rated float current, the chargerwill automatically switch over to quick charge mode and on reaching quick

charge voltage level, it will revert back to the float mode.xi) Fuse failure indication and alarm facility to be provided for SCR fuses, rectifier

fuses, main input fuses, load output fuses, battery fuse, capacitor bank fuse,A.C. input circuit breaker trip.

xii) Individual test switch to be provided for checking healthiness of lamps andalarm.

xiii) Audio and visual alarm indication for A.C. mains fail, phase fail, charger fail withaccept and reset push buttons to be provided.

xiv) Power factor improvement capacitor to be incorporated to ensure P.F. as perspecification.

xv) Lamps to be provided at AC mains available condition.

III. Electrical characteristics:-

The Float-cum-Boost charger for 48V/ 300 AH Plante Lead Acid Battery shallhave the following electrical characteristics:

i) Input source : 415 volt + 15% AC three-phase,4 wire ; Freq. 50 Hz + 5%.

ii) Unit Output :a) Voltage across battery terminals in float mode: 48V 55.2V DC

adjustable. This voltageshall be stabilised againstsupply voltage variation of+ 15%.

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b) Voltage across battery terminals in quick mode: 55.2V 56.4V DCadjustable. This voltageshall be stabilisedagainst supply voltagevariation of + 15%.

c) Voltage across Battery terminals in Boost mode: 56.4V 66V DC adjustable.This voltage shall bestabilised against supply

voltage variation of +15%.

d) Voltage across Load terminals : 48V (+10%, -5%) DC. This

voltage shall be stabilisedagainst supply voltage variationof + 15%.

e) No. of load output circuits with individualSwitch and fuse : 4 (four) nos.

f) Maximum rated current : 60Ag) Maximum load current : 30Ah) Maximum charge current : 30Ai) Output ripple on resistive

load (without Battery connected) :Not more than 3% RMS.

j) Voltage regulation(with supply voltage variation of +15%) : + 1% of output or better.

k) Power factor : 0.8 or better at rated loadcurrent and nominal supplyvoltage with battery floatingat the output of thecharger.

l) Efficiency : 70% or better at maximumoutput condition.

m) Type of cooling : Natural air cooling.

n) Operating temperature : Upto 45 Deg. C.

IV) Indicating Meters:-

The Float-cum-Boost charger for 48V/ 300 AH Plante Lead Acid Battery shall beequipped with indicating meters including but not limited to the following:-

a) Center zero DC Ammeter in linear scale for battery charge and dischargecurrent.

b) DC ammeter in linear scale for total output current.c) DC ammeter in linear scale for load current.d) DC voltmeter in linear scale with select switch to read battery and load

voltage.

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e) AC voltmeter with phase selector rotary switch for AC input voltage.f) AC Ammeter with phase selector rotary switch for AC line current.

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V) Switches:-

The Float-cum-Boost charger for 48V/ 300 AH Plante Lead Acid Battery shall beequipped with switches including but not limited to the following:-

a) Mains ON / OFF rotary switch.b) Battery output ON / OFF 2 pole rotary switch.c) Mode selector 2 pole, 4 way rotary switch (corresponding to auto, float, quick

and boost positions).d) Voltmeter selector switches for battery / load voltage indication.e) Individual load feeder ON / OFF rotary switches for four feeder lines.

f) 3 phase voltmeter selector switch for AC input voltage indication.g) 3 phase Ammeter selector switch for AC input line current measurement.

VI) Protections:-

The Float-cum-Boost charger for 48V/ 300 AH Plante Lead Acid Battery shallbe equipped with protections including but not limited to the following:-

a) A.C. input circuit breakerb) Fuse for rectified bridgec) Load input fused) Battery input fuse

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SCHEDULE A

GUARANTEED TECHNICAL PARTICULARS OF THE FLOAT-CUM-BOOST CHARGER FOR 48V / 300AH PLANTE LEAD ACIDBATTERY.----------------------------------------------------------------------

1. Manufacturers Name & Country of origin:

2. Type:

3. Gross Weight & Net Weight:

4. Dimension of cabinet in mm (height x weight x depth):

5. Is the equipment suitable to work in dust-laden atmosphere without air-conditioning:

6. Input source voltage and frequency:

7. Output DC voltage across battery terminals:

i) In Float mode:ii) In Quick mode:

iii) In Boost mode:

2. Output DC voltage across load terminals.

3. Number of load output circuits.

4. Maximum charge current.

5. Maximum load current.

6. Operating temperature.

Signature of the Tenderer

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