Battery Alarm 300

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Battery Alarm 300

IntroductionSubstation battery installations arerequired to provide not only dcauxiliary supplies for protection andcontrol equipment, but also tosupply trip and close currents tobreakers under tripping conditions.Monitoring of the performance ofthe dc system is thereforefundamental to the efficientoperation of the substation.

Figure 1: Battery Alarm 300

Battery Alarm 300 is designed toprovide comprehensive continuousbattery monitoring and to give localand remote indication of alarmconditions, including an impedancealarm. This alarm is designed tomonitor the ability of the battery tosupply a large current for trip/closerequirements, failure of which couldresult in extensive damage.

Early detection of such problemsusing Battery Alarm 300 allowseffective maintenance to bescheduled to help maintain theintegrity of the dc system.

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Product Features Customer Benefits

• Monitors ability of battery to supply load current • Ensures dc powered equipment such as criticalprotection relays and SCADA systems remainoperative

• Provides continuous in-service monitoring of the battery • The need for time consuming and costly site visits andbattery servicing by maintenance engineers isminimized

Batteries may remain safely in service after perceiveduseful life has expired, thus reducing replacemencosts

• Over and Under voltage alarms • Ensures battery charge is sufficient to support therequired voltage levelEnsures battery charger is performing correctly

• High Impedance alarm • Guards against high battery circuit impedance,caused by corroded terminals or internal build-up ofplate deposits, which would prevent the battery fromsupplying the required load current

Improves security of remote unmanned installationsagainst theft

• Earth Fault alarm • Protects against earth leakage which could preventthe battery supplying sufficient load current andwould also result in increased charging costs

• Fault indication LEDs and relay contacts • Local and remote alarms to facilitate fast andefficient fault diagnosis

• Models available for each of seven standard • Security of supply available for all dc powereddc voltages up to 220V dc equipment

• Wide voltage alarm setting ranges • Suitable for all types of battery including lead-acidand alkaline

• Loss of supply volts indicated via drop-off of normally • Battery Alarm does not require expensiveenergised relay, providing self checking maintenance

• Self-powered with minimal burden • Easily retrofitted to existing installations

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ApplicationFor substations it is important thatthe security of the supply ismaintained. This means not only thatthe battery voltage is withinrequired limits, but that earthleakage and any latent faults in thebattery and connections will notresult in failure to initiate trippingwhen a heavy current is demanded.For external wiring diagram seeFigure 2.

Battery Alarm 300 has beendesigned specifically for electricalsubstation batteries and has becomea standard for many utilities both fornew installations and for retro-fit toexisting batteries. It is suitable for allbatteries with an internal impedanceexceeding 0.1ý.

For battery charger systems fittedwith capacitor filtered outputs, theBattery Alarm requires a choke of>2 mH to be fitted at the output ofthe battery charger to ensure correctoperation of the high impedancealarm (see Figure 2).

WarningsCaution. 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 andnormal operation. This is toavoid resonance of the outputinductor with the systemcapacitance which may producedamaging high peak outputvoltages.

3 Terminations exposed duringinstallation and maintenancemay present a hazard unless theequipment is electricallyisolated.

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

Figure 2: External wiring diagram

DescriptionThe Battery Alarm is designed forflush panel mounting andconnection to the battery bus wiring.This forms the source of supply forthe electronics and also enables thedevice to monitor batteryperformance.

The outputs provided are volt freecontacts from two separate relays.

The first, designated URGENT, isnormally energised and willde-energise if the monitoredparameters deviate beyond presetlimits.

The second relay, designatedNON-URGENT, is normallyde-energised and will energise if themonitored parameters deviatebeyond preset limits. Each relaychannel is fitted with a preset timerwhich serves to inhibit alarms of atransient nature. Each relay can beconfigured to monitor any, or all, ofthe battery parameters. Two sets ofchangeover contacts are availableon each relay.

A version is available with bothrelays designated Non-urgent.Both relays are normallyde-energised and will energise if themonitored parameters deviatebeyond preset limits.

The unit has six LED indicators sothat fault recognition is possible inthe event 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 tothree circuit adjustmentpotentiometers for setting-up thefollowing:

• High impedance trip level

• Over voltage alarm point

• Under voltage alarm point

High Impedance AlarmThe high impedance alarm circuitmonitors the ability of the battery,together with the charger andassociated wiring, to provide aheavy current pulse.

The impedance monitoring circuitoperates by drawing a series ofheavy current pulses (approx. 1A)from the battery busbars. The valuesof these pulses are stored and, if a

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succession of pulses is low, thealarm will operate. The circuit isdriven by a low frequency oscillatorwhich gives a pulse rate of two persecond. The pulse duration isapproximately 50 microseconds.

The high impedance monitoringcircuit can be adjusted to monitorbattery impedances in the range of0.1ý to 5ý. It should be noted thatthe resistance of the fuses andconnecting cables will have aneffect on the potentiometer setting.Fuses should be rated at 2A and allwiring should be kept as short anddirect as possible.

Voltage Alarm LevelSettingsThe 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 variationof 80…140% in the input from thebattery. The power supply isgenerally designed to operate overa voltage range from maximumboost voltage down to a minimumvoltage below which a batterywould not normally be allowed todeteriorate. The over and undervoltage alarm settings must bewithin this range.

The adjacent figures can be used asa guide to suitable settings.

High voltage cut-off facility

A high voltage cut-off facility isachieved by routing the overvoltage alarm through the NON-URGENT relay with a short timedelay setting eg. 2s and alsothrough the URGENT relay with alonger time setting eg. 50s.

This provides a means of switchingoff the charger or performing otherswitching operations on detection ofa 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 voltageof (1.005 x Vtrip) ±0.5%.

Earth Fault AlarmThe earth terminal on the BatteryAlarm is connected to the case backplate and also to the earth faultcircuit input.

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

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

If either the positive or negative ofthe battery is earthed, the BatteryAlarm 300 will indicate an earthfault alarm. In the case when anearth fault relay is already fitted,then a Battery Alarm 300 modelwithout earth fault is recommended.

Alarm Indications andRelay OutputsA 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, theurgent alarm relay will release afterthe delay time.

On detection of an earth fault, theassociated panel led will light andthe NON-URGENT delay timer(usually 1s for earth faults) will start.The NON-URGENT relay will pick-up when 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 ranges

Battery voltages (VB) 24V, 30V, 32V, 48V, 50V, 60V,110V, 125V, 220V.

Operating range 80…140%VB

Burden 20mA nominalVoltage 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 5ký to 90kýAccuracy of trip level ±10%Hysteresis on trip level 5%Short circuit current <5mA

High impedance alarm (adjustable)Setting range 0.1ý …5.0ýAccuracy of setting ±0.05ýHysteresis on setting 0.05ý

Temperature

Nominal range of use –20°…+60°C

Reference temperature 23°C

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

temperature range

Electromagnetic Compatibility Directive 89/336/EECEmissions standard EN 50081-2 1994 Industrial environmentImmunity standard EN 50082-2 1995 Industrial environment

(IEC 60801 parts 2, 3 and 4)Susceptibility to ElectrostaticDischarge 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 EN 61010-1 1993 safety requirements.

Timers

Alarm time delay settings 1, 2, 4, 8, 16, 32, 64, 128s(other settings available on request)

Accuracy of setting ±10% (±0.25s)

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Output relays

URGENT alarm relay 2 changeover contacts

NON-URGENT alarm relay 2 changeover contacts

Contact ratings

Max. switching power 60W; 62.5VAMax. switching voltage 220V dc; 250V acMax. switching current 2AMax. carrying current 3AIsolation 750Vrms across open contactsInsulation resistance >100Mý at 500V dc

Miscellaneous

Series mode noise (ripple) 10%VB(pk-pk) 50…120Hz

Common mode noise 100Vrms 45…65Hz

Isolation 1kVrms between inputs and alarmcontacts

Impulse 5kV (1.2/50µs) to IEC 60060-1/BS923 and IEC 60255-5/BS5992-3

High frequency disturbance To IEC 60255-22-1/BS142Section 1.5.1

Overload ratings 2 x VB continuous or 200V dcwhichever is lower

220V version 350V dc continuous

Humidity 0…93% +2% –3% RH

Terminals Barrier type M3.5

LED indications

Power 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 onreset of Urgent alarm relay.

If the supply voltage falls below66%VB for longer than 50ms, aninstantaneous URGENT alarm isgiven. When the supply voltagereturns to above 66%VB, a poweron reset occurs after a time delay of1 second.

Information Requiredwith OrderNominal battery voltage

Battery type (eg lead acid, nickelcadmium, etc.)

Number of cells

High and low voltage alarm points

Earth fault trip level

Relay alarm designations(if different from configurationshown on page 5)

Alarm time delays

Outline Dimensions

TRANSMISSION & DISTRIBUTION Protection & Control, HQ, 60 Route de Sartrouville, BP58, 78230 Le Pecq Cedex, FranceTel: +33 (0) 134 80 79 00 Fax: +33 (0) 134 80 79 13 Email: protection.control@tde.alstom.com Internet: www.tde.alstom.com

©2000 ALSTOM, ALSTOM, the ALSTOM logo and any alternative version thereof are trademarks and service marks of ALSTOM.Other names mentioned, registered or not, are the property of their respective companies.

Our policy is one of continuous development. Accordingly the design of our products may change at any time. Whilst every effort is made to produce up to date literature, this brochure shouldonly be regarded as a guide and is intended for information purposes only. Its contents do not constitute an offer for sale or advice on the application of any product referred to in it.

We cannot be held responsible for any reliance on any decisions taken on its contents without specific advice. Pub

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