Battery Alarm 300

Publication I6009K

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The Company and its Products

GEC ALSTHOM T&D Protection & Control Limited is part of GEC ALSTHOM,one of the largest electrical power generation, transmission and distributiongroups in the world.

It is an acknowledged world leader in the design and production of relays andinstrumentation. This position has been achieved through a continuing policy ofincreasing investment in new product development.

The company is represented all over the world and has its British base atStafford where approximately 1,600 personnel are employed.

GEC ALSTHOM T&D Protection & Control markets a quality range of electricalinstrumentation serving the control requirements of the power generation,transmission, distribution and industrial process markets.

This product range includes:

Panel instruments (conforming to DIN, BS and ANSI standards)

Istat electrical transducers

MotorMaster motor protection relays

Novar capacitor controllers

R30 Chart recorders

Battery alarms

Rotary switches

Prima Auxiliary Relays

Expert technical support for product selection, application and after salesservice is available through a network of over 80 established representativesaround the world.

Substation battery installations are required to provide not only dc auxiliary supplies for protection and controlequipment, but also to supply trip and close currents to breakers under tripping conditions. Monitoring of theperformance of the dc system is therefore fundamental to the efficient operation of the substation.

Battery Alarm 300 is designed to provide comprehensive continuous battery monitoring and to give local and remoteindication of alarm conditions, including an impedance alarm. This alarm is designed to monitor the ability of the batteryto supply a large current for trip/close requirements, failure of which could result in extensive damage.

Early detection of such problems using Battery Alarm 300 allows effective maintenance to be scheduled to help maintainthe integrity of the dc system.

Product Features Monitors ability of battery to supply load current

Provides continuous in-service monitoring of the battery

Over and Under voltage alarms

High Impedance alarm

Earth Fault alarm

Fault indication LEDs and relay contacts

Models available for each of seven standard dc voltages up to 220V dc

Wide voltage alarm setting ranges

Loss of supply volts indicated via drop-off of normally energized relay, providing self checking

Self-powered with minimal burden

Customer Benefits Ensures dc powered equipment such as critical

protection relays and SCADA systems remainoperative

The need for time consuming and costly site visits and battery servicing by maintenance engineers is minimized

Batteries may remain safely in service after perceived useful life has expired, thus reducing replacement costs

Ensures battery charge is sufficient to support the required voltage level

Ensures battery charger is performing correctly

Guards against high battery circuit impedance, causedby corroded terminals or internal build-up of platedeposits, which would prevent the battery fromsupplying the required load current

Improves security of remote unmanned installations against theft

Protects against earth leakage which could prevent thebattery supplying sufficient load current and wouldalso result in increased charging costs

Local and remote alarms to facilitate fast and efficient fault diagnosis

Security of supply available for all dc poweredequipment

Suitable for all types of battery including lead-acid and alkaline

Battery Alarm does not require expensive maintenance

Easily retrofitted to existing installations

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312645879

111012

Non-urgent

Urgent

To telemetry

E

2A rating Busbars tobattery loads

Batte

ry

Char

ger

Optional choke(Required when battery charger has capacitor filtered output)

FS1

2A ratingFS2

Figure 1: External wiring diagram

Note: The Battery Alarm is shown in the energised state. Under healthyoperating conditions the urgent relay is operated and the non-urgentrelay is released.

Application

For substations it is important that thesecurity of the supply is maintained.This means not only that the batteryvoltage is within required limits, butthat earth leakage and any latentfaults in the battery and connectionswill not result in failure to initiatetripping when a heavy current isdemanded. For external wiringdiagram see Figure 1.Battery Alarm 300 has been designedspecifically for electrical substationbatteries and has become a standardfor many utilities both for newinstallations and for retro-fit to existingbatteries. It is suitable for all batterieswith an internal impedance exceeding0.1Ω.For battery charger systems fitted withcapacitor filtered outputs, the BatteryAlarm requires a choke of >2 mH tobe fitted at the output of the batterycharger to ensure correct operation of the high impedance alarm (see Figure 1).

Warnings

Caution. Refer to the Operation &Maintenance Manual (I9-100)before installing, commissioningor operating the equipment.

1 Installation, commissioning andmaintenance should only becarried out by qualifiedpersonnel.

2 Battery charger systems with aninductive output element only,should have a suitable loadconnected, such as a battery,during commissioning and normaloperation. This is to avoidresonance of the output inductorwith the system capacitancewhich may produce damaginghigh peak output voltages.

3 Terminations exposed duringinstallation and maintenance maypresent a hazard unless theequipment is electrically isolated.

4 The equipment should only beoperated as intended e.g. withcovers in place and the earthconductor connected to maintainthe incorporated safety features.

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Description

The Battery Alarm is designed for flushpanel mounting and connection to thebattery bus wiring. This forms thesource of supply for the electronicsand also enables the device to monitorbattery performance. The outputs provided are volt freecontacts from two separate relays. The first, designated URGENT, isnormally energized and will de-energize if the monitoredparameters deviate beyond presetlimits.The second relay, designated NON-URGENT, is normally de-energized and will energize if themonitored parameters deviate beyondpreset limits. Each relay channel isfitted with a preset timer which servesto inhibit alarms of a transient nature.Each relay can be configured tomonitor any, or all, of the batteryparameters. Two sets of changeovercontacts are available on each relay.A version is available with both relaysdesignated NON-URGENT. Bothrelays are normally de-energised andwill energise if the monitoredparameters deviate beyond presetlimits.

The unit has six LED indicators so thatfault recognition is possible in theevent of a sustained fault. These indicators display:

Power supply operative Earth fault positive Earth fault negative High impedance Over voltage Under voltage

The window and front panel are cutaway to provide easy access to threecircuit adjustment potentiometers forsetting-up the following:

High impedance trip level Over voltage alarm point Under voltage alarm point

High impedance alarm

The high impedance alarm circuitmonitors the ability of the battery,together with the charger andassociated wiring, to provide a heavycurrent pulse.The impedance monitoring circuitoperates by drawing a series of heavycurrent pulses (approx. 1A) from thebattery busbars. The values of thesepulses are stored and, if a successionof pulses is low, the alarm willoperate. The circuit is driven by a lowfrequency oscillator which gives apulse rate of two per second. The pulse duration is approximately50 microseconds.The high impedance monitoring circuitcan be adjusted to monitor batteryimpedances in the range of 0.1Ω to

5Ω. It should be noted that theresistance of the fuses and connectingcables will have an effect on thepotentiometer setting. Fuses should berated at 2A and all wiring should bekept as short and direct as possible.

Voltage alarm level settings

The voltage levels specified willdepend on the operating conditions of the battery installation and thepurpose for which the alarms arerequired. However, the workingvoltage range of the Battery Alarmmust be taken into account whendeciding on a specification.

The Battery Alarm power supply canaccommodate a maximum variation of 80…140% in the input from thebattery. The power supply is generallydesigned to operate over a voltagerange from maximum boost voltagedown to a minimum voltage belowwhich a battery would not normally beallowed to deteriorate. The over andunder voltage alarm settings must bewithin this range.

The adjacent figures can be used as aguide to suitable settings.

High voltage cut-off facility

A high voltage cut-off facility isachieved by routing the over voltagealarm through the NON-URGENTrelay with a short time delay settingeg. 2s and also through the URGENTrelay with a longer time setting eg. 50s.

This provides a means of switching off the charger or performing otherswitching operations on detection of a high voltage alarm condition.

A similar low voltage cut-off versioncan also be provided.

Parameter (per cell) Lead acid Alkaline

Nominal volts 2.00 1.20

Max volts on boost 2.60 1.68

Working volts on charge 2.27 1.46

Minimum volts 1.85 1.00

Low alarm operation 2.14 1.32

High alarm operation 2.40 1.52

For example: For a 55-cell lead acid battery

Low alarm setting = 55 x 2.14 = 117.7V

High alarm setting = 55 x 2.40 = 132V

The over and under voltage alarm levels are adjustable (see technicalspecification).

NoteThe over and under voltage alarms have built-in hysteresis to prevent contactchatter. This hysteresis (or pick up/drop off differential) will result in a highalarm reset voltage of (0.995 x Vtrip) ±0.5% and a low alarm reset voltage of(1.005 x Vtrip) ±0.5%.

Earth fault alarm

The earth terminal on the BatteryAlarm is connected to the case backplate and also to the earth fault circuitinput.

A leakage path from either thepositive or the negative pole of thebattery to earth will cause a current to flow in the input to the earth faultcircuit. If this current exceeds apredetermined value, the earth faultrelay will operate and the relevant LED will illuminate.

The earth fault trip level is presetwithin the range 5…90kΩ and issymmetrical for both positive andnegative earth faults, irrespective of battery voltage.

If either the positive or negative of thebattery is earthed, the Battery Alarm300 will indicate an earth fault alarm.In the case when an earth fault relay isalready fitted, then a Battery Alarm300 model without earth fault isrecommended.

Alarm indications and relayoutputs

A popular configuration for alarmrelay outputs is:

– URGENT alarm for over voltage,under voltage and highimpedance;

– NON-URGENT alarm for earthfaults.

On detection of an over voltage,under voltage or high impedancefault, the associated panel LED willlight immediately. At this stage theurgent alarm delay will start to timeout and, if the fault persists, the urgentalarm relay will release after the delaytime.

On detection of an earth fault, theassociated panel LED will light and theNON-URGENT delay timer (usually 1s for earth faults) will start. The NON-URGENT relay will pick-upwhen the timer times-out.

Each relay channel is fitted with atimer and each channel can beconfigured to monitor any of thebattery parameters.

Both relays have two sets of volt-freechangeover contacts which can beused for local and remote alarms,SCADA inputs etc.

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Technical Specifications

Battery Voltage RangesBattery voltages (VB) 24V, 30V, 32V, 48V, 50V, 60V,

110V, 125V, 220V.Operating Range 80…140%VBBurden 20mA nominal

Voltage alarm levels (adjustable)Under voltage range 80…110%VBOver voltage range 105…140%VBAccuracy of setting ±0.5%Hysteresis on setting 0.5%

Earth leakage protection (preset)Trip level range 5kΩ to 90kΩAccuracy of trip level ±10%Hysteresis on trip level 5%Short circuit current <5mA

High impedance alarm (adjustable)Setting range 0.1Ω …5.0ΩAccuracy of setting ±0.05ΩHysteresis on setting 0.05Ω

TemperatureNominal range of use –20°…+60°CReference temperature 23°CTemperature coefficient

Voltage alarms ±0.006%/°CEarth leakage alarm ±0.06%/°CTimer settings ±0.06%/°CHigh impedance alarm <0.1Ω deviation in setting over

temperature range

Electromagnetic Compatibility Directive 89/336/EECEmissions standard EN50081-2 1994 Industrial environmentImmunity standard EN50082-2 1995 Industrial environment

(IEC801 parts 2, 3 and 4)Susceptibility to Electrostatic Discharge 8kV air discharge/4kV contact.WARNING: This specification applies when the front cover is fitted. If thefront cover is removed to gain access to the adjustment potentiometers thenappropriate ESD protection must be taken.

Low Voltage Directive 72/23/EECDesigned to EN61010-1 1993 safety requirements.

TimersAlarm time delay settings 1, 2, 4, 8, 16, 32, 64, 128s

(other settings available on request)Accuracy of setting ±10% (±0.25s)

Output relaysURGENT alarm relay 2 changeover contactsNON-URGENT alarm relay 2 changeover contacts

Contact ratingsMax. switching power 60W; 62.5VAMax. switching voltage 220V DC; 250V ACMax. switching current 2A

Max. carrying current 3AIsolation 750Vrms across open contactsInsulation resistance >100MΩ at 500V DC

MiscellaneousSeries mode noise (ripple) 10%VB(pk-pk) 50…120HzCommon mode noise 100Vrms 45…65Hz

Isolation 1kVrms between inputs and alarmcontacts

Impulse 5kV (1.2/50µs) to IEC60-1/BS923 and IEC255-5/BS5992-3

High frequency disturbance To IEC255-22-1/BS142 Section 1.5.1Overload ratings 2 x VB continuous or 200V dc

whichever is lower220V version 350V dc continuousHumidity 0…93% +2% –3% RHTerminals Barrier type M3.5

LED indicationsPower on Green LEDEarth fault (positive) Red LEDEarth fault (negative) Red LEDHigh impedance Red LEDOver voltage Red LEDUnder voltage Red LED

Fail to safety and power on reset of URGENT alarm relay. If the supply voltagefalls below 66%VB for longer than 50ms, an instantaneous URGENT alarm isgiven. When the supply voltage returns to above 66%VB, a power on resetoccurs after a time delay of 1 second.

Information required with orderNominal battery voltageBattery type (eg lead acid, nickel cadmium, etc.)Number of cellsHigh and low voltage alarm pointsEarth fault trip levelRelay alarm designations (if different from configuration shown on page 5)Alarm time delays

96 104 245

96

Panel cut-out 92 square–0+0.8 (Dimensions in mm)

Outline dimensions

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