battery alarm user manual

USER MANUAL BATTERY ALARM 300

Battery Alarm User Manual BA300

Page 1/21

CONTENTS

1. DESCRIPTION 4

Introduction 4

1.1.1 Battery Alarm 300 4

1.2 Features 4

1.2.1 Battery Voltage Ranges 4

1.2.2 Voltage Alarm Levels (Adjustable) 4

1.2.3 Earth Leakage Detection (Preset) 4

1.2.4 High Impedance Alarm (Adjustable) 5

1.2.5 Temperature 5

1.2.6 Electromagnetic Compatibility 5

1.2.7 Timers 5

1.2.8 Relay Outputs 5

1.2.9 Miscellaneous 5

1.2.10 LED Indicators 5

1.2.11 Fail to Safety and Power on reset 6

1.2.12 Electrostatic Discharge 6

2. PRINCIPLES OF OPERATION 7

2.1 Construction 7

2.2 Input connections 7

2.3 Earth Leakage current monitoring 8

2.4 High Impedance monitoring 9

3. CIRCUIT BLOCK DIAGRAMS 10

3.1 Battery Alarm connections to a high impedance charger 10

3.2 Battery Alarm connections to a low impedance charger using an external choke 10

3.3 Routing of alarm functions through selector links 11

3.4 Time delay selection for output relays 11

3.5 Voltage response of a healthy battery to a heavy current load 12

3.6 Voltage response of a faulty battery to a heavy current load 12

3.7 Operation of high impedance circuit 13

4. ON SITE COMMISSIONING 14

4.1 Mounting 14

4.2 Connection 14


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5. BENCH TESTING AND CALIBRATION 15

5.1 Isolation tests 15

5.2 Connection 15

5.3 Alarm Configuration and Time Delay Setting 15

5.4 Under voltage calibration (figure 3) 17

5.5 Over voltage calibration (figure 3) 17

5.6 Positive Earth Fault (figure 3) 17

5.7 Negative Earth Fault (figure 3) 17

5.8 High or Low voltage cut off model 18

6. BATTERY ALARM 315 20

7. DIMENSIONS 21

7.1 Battery Alarm 300 case dimensions 21

7.2 Battery Alarm 315 case dimensions 21


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Page 4/21

1. DESCRIPTION

1.1 Introduction

1.1.1 Battery Alarm 300

Monitoring of battery supplies using a

Battery Alarm 300 in unmanned

substations ensures security of supply.

A low impedance battery with voltage

within limits and low earth leakage

prevents failure to trip circuit breakers

when heavy current is demanded.

1.2 Features

Alarms for positive and negative

earth fault, high impedance,

over and under voltage.

Two time-delayed output relays: -

Failsafe urgent alarm for high and low voltage and high impedance

Non urgent alarm for earth leakage

Self powered

For use with floating batteries with no battery terminals connected to earth (ground)

96 mm front of panel mounting DIN case

1.2.1 Battery Voltage Ranges

Battery Voltages (Vb) 24 V, 30 V, 32 V, 48 V, 50 V, 60 V, 110 V, 125 V, 220 V Operating range -20%…+40% Vb Burden 20 mA (nominal)

1.2.2 Voltage Alarm Levels (Adjustable)

Accuracy of setting +/- 0.5% Hysteresis of setting 0.5% Under Voltage alarm range -20%…+10% Vb Over Voltage alarm range +5%…+40% Vb

1.2.3 Earth Leakage Detection (Preset)

Accuracy of trip level +/- 10% Hysteresis on trip level 5% Trip level range 5 kOhm to 90 kOhm Short circuit current < 5 mA

!

POWER ON

POSITIVE

NEGATIVE

HIGH IMPEDANCE

OVER VOLTAGE

UNDER VOLTAGE

EARTH FAULT

OVERUNDER

VOLTAGE SETTINGS

HIGH IMPEDANCE


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1.2.4 High Impedance Alarm (Adjustable)

Accuracy of setting < 0.05 Ohm Hysteresis on setting 0.05 Ohm Operating range 0.1…5.0 Ohm

1.2.5 Temperature

Reference temperature 23 deg C Nominal Range of use -20…60 deg C Temperature coefficient Voltage alarm +/- 0.006 % / deg C Earth Leakage alarm +/- 0.06 % / deg C Timer settings +/- 0.06 % / deg C High Impedance < 0.1 Ohm deviation in setting over temperature range –20…60 deg C

1.2.6 Electromagnetic Compatibility

Emissions EN50081-1 Class B Immunity EN50082-2 (IEC 801 parts 2, 3 and 4)

1.2.7 Timers

Alarm time delay settings 1, 2, 4, 8, 16, 32, 64, 128 seconds (other settings available on request where longest time is then divided by alarm delay jumper selector in multiples of 2)

Accuracy of settings +/- 10 % +/- 0.25 seconds

1.2.8 Relay Outputs

Urgent alarm relay double pole changeover contacts Non urgent alarm relay double pole changeover contacts Contact ratings Maximum switching power 60 W, 62.5 VA Maximum switching voltage 220 V dc , 250 V ac Maximum switching current 2 A Maximum carrying current 3 A Isolation 750 V rms between open contacts Insulation resistance >100 Mohm at 500 V dc

1.2.9 Miscellaneous

Series mode noise (ripple) 10 % Vb (pk-pk) 50…120 Hz Common mode noise 100 V rms 45…65 Hz Isolation 1 kV rms between inputs and alarm contacts Impulse Test 5 kV (1.2/50 us) to BS923 & IEC 255-4 Surge Withstand to IEC 255-4 and ANSI C37-90A IEEE Std 472 SWC where applicable Overload Ratings 2 x Vb continuous or 200 V which ever is the lower Humidity (non condensing) 0…93 +/- 3 %

1.2.10 LED Indicators

Power on - Green LED Positive earth fault - Red LED Negative earth fault - Red LED High Impedance - Red LED Over voltage - Red LED Under voltage - Red LED


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1.2.11 Fail to Safety and Power on reset

If the supply voltage falls below 66% Vb for longer than 50 ms then an instantaneous urgent alarm is given. When the supply voltage returns to above 66% Vb a ‘power-on reset’ occurs after a time delay of 1 s

1.2.12 Electrostatic Discharge

Susceptability to electrostatic discharge 8kV air discharge /4kV contact. Warning : This specification applies only when the front cover is fitted. If the front cover is removed to gain access to the adjustment potentiometers then appropriate ESD protection must be taken.


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2. PRINCIPLES OF OPERATION

2.1 Construction

The battery alarm is mounted in a flameproof front of panel mounted 96mm DIN standard case.

Access to adjustment potentiometers is made by removal of a protective front plate across the lower half of the battery alarm.

Alarms are shown on red LEDs on the front of the battery alarm.

A green LED indicates a healthy power supply.

The Battery Alarm 300 is built using four printed circuit boards (pcbs) which are connected together by connectors to form a box assembly which fits into the 96 x 96 x 104 mm case.

The rear pcb (ZI0203001) carries the alarm relays, high impedance current pulse FET and earth leakage dropper resistors.

The bottom pcb (ZI0203002) carries the earth leakage detection circuitry and the high impedance detection circuitry.

The front pcb (ZI0203003) carries the LED alarm indicators, under and over voltage alarm circuitry and the clock circuitry. The front pcb also carries the adjustment potentiometers for under voltage alarm, over voltage alarm and high impedance alarm.

The top pcb carries the alarm selection links, timers and alarm relay drivers.

Figure 4 shows the block diagram for the Battery Alarm 300 and illustrates the functions and interconnections of each pcb.

Compliance to the European EMC directive 89/336/EEC for RFI emissions and immunity has been achieved by careful consideration of pcb track layout, the use of multi-layer pcb groundplanes and decoupling capacitors placed in vulnerable circuit areas.

2.2 Input connections

The Battery alarm positive terminal is connected to the positive terminal of the battery through a fuse rated for at least 2 Amps. See section 3.1

The Battery alarm negative terminal is connected to the negative terminal of the battery through a fuse rated for at least 2 Amps. See section 3.1

The average current drawn by the battery alarm is less than 30 mA. However, it is necessary to use fuses rated for at least 2 Amps since their impedance is then not too great to affect the high impedance settings of the battery alarm.

When the battery alarm is connected to a battery that is being used with a charger with a low output impedance, such as a charger which uses a capacitor as its final stage of smoothing, then the use of a chokes is necessary. See section 3.2

The choke gives a low resistance path to the normal flow of charging current to the battery, but it offers a high impedance to the short pulses of the high impedance circuit of the battery alarm. Thus the charger is effectively isolated from the battery for the measurement of battery impedance.

Connection to earth (ground) is made to the terminal ‘E’ on the battery alarm when the battery being monitored is floating from earth potential. This terminal can be left unconnected when the battery being monitored is solidly grounded.


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2.3 Earth Leakage current monitoring

The battery alarm is designed for use with floating batteries that have no connections of either terminal to ground. If a second earth fault detection device is connected to the battery or via the charger then this must be removed if the battery alarm 300 earth leakage detection circuit is to be used. One ground fault detection system can alter the settings of the other detection system often resulting in erroneous ground fault trip indications.

The earth leakage circuit in the battery works by placing a set of resistors across the battery terminals. The centre point of these resistors is then connected to earth (ground) via the terminal ‘E’. With a totally floating battery the voltage of the positive terminal will then float at plus half the battery volts and the negative terminal will float at minus half the battery volts

Any leakage current will pull the voltage of the centre point either towards the positive battery terminal for a positive earth fault or towards the negative terminal voltage for a negative earth fault.

This voltage shift is detected across resistor R3 by a level detecting circuit. This is preset to the required sensitivity for earth fault detection. A typical sensitivity for earth fault alarm level is 20 kOhm.

Figure 1

Battery Alarm 300 earth leakage input circuit A bidirectional moving coil instrument can be connected in series with the earth (ground) connection as shown above to monitor any earth leakage current. The rating should be -1…0…1 mA for nominal battery voltages up to 120 V. The rating should be -2…0…2 mA for nominal battery voltage of 220 V.

Earth Leakage Instrument

Leakage Resitance

R1

R2

R3 To earth fault trip comparator

E

+

_ Battery _

Battery +


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2.4 High Impedance monitoring

The Battery Alarm 300 generates a short current pulse of duration 50 µs by energising a transistor which briefly connects a resistor across the battery terminals. This draws a pulse of current of approximately one amp during the time that the transistor is turned on. This current causes a small drop in battery voltage. This voltage drop is measured by the Battery Alarm 300 and it is used to assess the impedance of the battery. A larger voltage drop indicates a higher impedance is present and an alarm can be set to indicate that an impedance increase has exceeded the set level. The current pulse is very short, so measurement is affected by the impedance of the whole battery cicuit rather than just the resistance of the battery. Since the impedance of battery circuits are always different, depending on site conditions, the impedance setting is set up on site. The battery alarm 300 measures the impedance at the terminals of the battery alarm. All impedances between the battery alarm and the battery terminals add to the battery impedance and so these need to be kept to a minimum in order to avoid unwanted alarm conditions. Wiring should be kept as short as possible and the series fuses fitted to the battery alarm should be rated at 2A rating in order to keep the series resistance as low as possible. The battery charger will be connected in parallel with the battery being monitored and so the impedance of the charger will appear in parallel with that of the battery. Where the charger impedance is high no effect is seen on the impedance measurements of the Battery Alarm 300. Direct connection may then be made to the battery and battery charger combination. However if the battery charger exhibits a low impedance across its output terminals then an extra choke must be introduced into the battery charger circuit. This effectively isolates the charger from the battery alarm impedance pulses which then only measure the impedance of the battery. A typical size of choke to be fitted is 0.5 mH choke which is rated for the maximum charger current. For example a 20 A rating choke should be used with a 20 A rating charger.


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3. CIRCUIT BLOCK DIAGRAMS

3.1 Battery Alarm connections to a high impedance charger

Batteries connected to a charger which has a high impedance coil on its output circuit may be monitored using a battery alarm connected directly across the battery terminals

3.2 Battery Alarm connections to a low impedance charger using an external choke

Applications with chargers with a low impedance output (from smoothing capacitors connected internally to the charger) require the use of an interposing choke connected as above.

Charger

FuseBusbarsto load

BA300+

-

E

Fuse

+

Choke

FuseBusbarsto load

BA300+

-

E

Fuse

+

Charger


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3.3 Routing of alarm functions through selector links

Each alarm function is indicated by an LED on the front of the Battery alarm. Each alarm may be connected by means of a pcb jumper to one, both or neither of the output relays. 3.4 Time delay selection for output relays

A time delay on each output relay may be selected by a set of jumpers on the pcb where each step doubles the selected delay time

Urgentalarm

Nonurgentalarm

Outputrelay

Outputrelay

Time selector links

Urgentalarm

Volts

Alarm selector linksOverUnder

HighImpedance

EarthFault

+-

Power supply

Non urgentalarm


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3.5 Voltage response of a healthy battery to a heavy current load

Following a heavy curent load, such as tripping a breaker, the battery voltage drops and then recovers.The delay time on the output relay is set to longer than the normal recovery time for a healthy battery and charger. The output relay will not trip under these conditions. 3.6 Voltage response of a faulty battery to a heavy current load

A fautly battery can take longer to recover to its working voltage after supplying a heavy current load. In this case the alarm delay time is exceeded and an alarm is given by the output relay closing after the set alarm delay time.

Healthy Battery

Voltage

Battery voltsTrip level

Time

Alarm delay time

Low voltage response

Faulty BatteryVoltage

Battery voltsTrip level

Time

Alarm delay time

Low voltage response


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3.7 Operation of high impedance circuit

Short current pulses are drawn from the battery using a switched resistive load. The small resulting drops in battery voltage are compared with a set level to monitor the impedance of the battery on a continual basis.

Outputcircuit

R battery

VREFComparator

High impedance circuit


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4. ON SITE COMMISSIONING

4.1 Mounting

The battery alarm is designed for flush panel mounting in a cut-out measuring 92 mm square (+0.8, -0.0) and secured in position with the clamps provided. 4.2 Connection

Before connecting the equipment it should be checked to ensure that it is suitably rated for the battery installation to be monitored, otherwise damage may result. The battery alarm should be connected as shown in figure 3. The + and – leads should be connected as close as is practicable to the battery terminals via 2 Amp rated anti surge fuses. (red spot type of panel fuse is suitable). The resistance of the fuses will appear in series with the battery being monitored and so they should be rated for 2A in order to reduce the series resistance of the system. If the battery has one pole grounded then the earth terminal ‘E’ may be left unconnected in order to avoid a constant earth fault alarm. Battery alarms having the earth fault measurement and LED indicator components not fitted are available for these applications. The output relay contacts are connected to the telemetry or annunciators as required. Both normally open and normally closed contacts are available. Note that the Urgent output relay contacts will change state when the battery voltage is applied to the battery alarm. This ensures an alarm occurs for low or zero monitored battery voltage. Settings 1. Over voltage (high voltage) alarm level is factory set but may be adjusted using the

potentiometer accessible from the front of the battery alarm. 2. Under voltage (low voltage) alarm level is factory set but may be adjusted using the

potentiometer accessible from the front of the battery alarm. 3. Earth fault alarm levels are factory set using fixed resistor values. Typical sensitivity 20 kOhm. 4. High Impedance is adjusted using the potentiometer accessible from the front of the battery

alarm. See section 5.0. It is slowly adjusted until the alarm trip level is reached where the high impedance LED is at the point of illuminating / extinguishing. This is the set impedance level of the battery circuitry. The setting should then be made less sensitive by rotating the potentiometer at least half a turn in the direction where the alarm LED extinguishes. The battery alarm is now set for an alarm following an increase in impedance of 0.1 Ohm.


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5. BENCH TESTING AND CALIBRATION 5.1 Isolation tests

Before testing and calibration, the battery alarm must be isolation tested between inputs and alarm relay outputs at 1kV RMS ac 50 Hz for 1 minute (or at 1.25 kV RMS for 1 s). Each normally open contact must be isolation tested at 750 V RMS ac 50HZ for 1 minute or for 1kV RMS for 1 s. The unit must then be insulation tested at 500 V dc when the resistance must be greater than 100 Mohm. 5.2 Connection

The battery should be connected to the test equipment as shown in figure 2. Set the variable dc power source to the nominal battery voltage rating of the unit. The earth should not be connected but left floating. The five Ohm variable resistance VR1 should be set at 0 Ohm. Under these conditions the battery alarm should draw approximately 20 mA and the status of the alarm contacts should be: - Urgent alarm: tripped : 1-2 and 4-5 contacts closed Non urgent alarm : released: 7-9 and 10-12 contacts closed 5.3 Alarm Configuration and Time Delay Setting

Each of the five alarm conditions(over voltage HV, under voltage LV, positive earth fault +EL, negative earth fault -EL, and high impedance IMP) can be routed to either or both of the alarm output relays. Use links on LK40 to set route to desired output relay (Urgent relay or Non urgent relay) – see figure 2 The time delay of the Urgent relay is set by LK41 – see figure 2. The time delay of the Non Urgent relay is set by LK42 – see figure 2. Figure 2 To gain access to these links, the case must be removed to expose the internal circuit boards. Warning : These boards are susceptible to electrostatic discharge and appropriate ESD protection must be taken.

LK42

LK40

LK41

1s

2 4 8 16

32

64

128

1s

2 4 8 16

32

64

128

-EL +EL IMP LV HV -EL +EL IMP LV HVN

ON

UR

GE

NT

UR

GE

NT


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Figure 3

Vbatt Variable dc power supply with 1 A capability.

Output impedance less than 0.2 ohm (if not, fit capacitor C1 as shown)

VR1 0…5 Ohm variable resistance (increments of 0.1 Ohm or less) for checking high impedance alarm

VR2 0…100 kOhm variable resistance (increments of 100 Ohm or less) for checking earth fault alarm

A, B Earth fault test connection points

V Voltmeter (10,000 Ohm/V or higher)

I Low impedance milliammeter to monitor 20 mA supply current

LINK 1 Link out milliammeter when checking high impedance alarm

E V

I

VR2

VR1

C1 Vbatt

LINK 1

B

A

Battery Alarm 300


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5.4 Under voltage calibration (figure 3)

Adjust the supply voltage until the voltmeter reads the value specified for the under voltage alarm trip.

Slowly adjust the ‘under’ potentiometer until the ‘under voltage’ LED illuminates.

Increase the supply voltage until the LED turns off then decrease the voltage until the LED turns on and check that the hysteresis is < 0.5% on alarm level setting

Increase the supply voltage until the LED turns off.

Decrease the supply voltage until the ‘under voltage’ LED illuminates and check the time interval to alarm relay trip corresponds to setting +/- 10%, +/- 0.25 s

5.5 Over voltage calibration (figure 3)

Adjust the supply voltage until the voltmeter reads the value specified for the over voltage alarm trip.

Slowly adjust the ‘under’ potentiometer until the ‘over voltage’ LED illuminates.

Decrease the supply voltage until the LED turns off then increase the voltage until the LED turns on and check that the hysteresis is < 0.5% on alarm level setting

Decrease the supply voltage until the LED turns off.

Increase the supply voltage until the ‘over voltage’ LED illuminates and check the time interval to alarm relay trip corresponds to setting +/- 10%, +/- 0.25 s

5.6 Positive Earth Fault (figure 3)

Adjust the supply voltage to the nominal battery voltage rating of the unit. Set earth fault resistance VR2 to its maximum value of 100 kOhm.

Connect the earth fault resistance to the positive terminal of the supply voltage (point A).

Reduce the earth fault resistance until the ‘positive earth fault’ LED illuminates.

Check that the trip resistance corresponds to within +/- 10% of the specified earth fault alarm resistance setting.

Increase the earth fault resistance until the ‘positive earth fault’ LED turns off and check the hysteresis level is < 5% of the alarm earth fault resistance.

Decrease the earth fault resistance until the ‘positive earth fault’ LED illuminates and check the time interval to alarm relay trip corresponds to setting +/- 10%, +/- 0.25s.

Disconnect the earth fault resistance from the positive terminal of the supply voltage (point A)

5.7 Negative Earth Fault (figure 3)

Adjust the supply voltage to the nominal battery voltage rating of the unit. Set earth fault resistance VR2 to its maximum value of 100 kOhm.

Connect the earth fault resistance to the negative terminal of the supply voltage (point B).

Reduce the earth fault resistance until the ‘negative earth fault’ LED illuminates.

Check that the trip resistance corresponds to within +/- 10% of the specified earth fault alarm resistance setting.

Increase the earth fault resistance until the ‘negative earth fault’ LED turns off and check the hysteresis level is < 5% of the alarm earth fault resistance.

Decrease the earth fault resistance until the ‘negative earth fault’ LED illuminates and check the time interval to alarm relay trip corresponds to setting +/- 10%, +/- 0.25s.

Disconnect the earth fault resistance from the negative terminal of the supply voltage (point A)


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5.8 High or Low voltage cut off model

The high or low voltage cut-off facility is achieved by routing only a single over or under voltage alarm into the non-urgent alarm relay with a short time delay setting (for example 2 seconds). This output relay set for a high voltage alarm can then be used to cut off a charger if the voltage of the battery rises too high. The over voltage and /or under voltage alarm is also routed with all other required alarms into the urgent alarm relay with a longer time delay setting (for example 50 seconds). This alarm is then used as a general purpose alarm.


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Figure 4

Battery Alarm 300 block diagram

ZI0203 003

ZI0203 001 ZI0203 002

ZI0203 004 PL7 PL8

SK8SK7 PL2 PL4

SK2 SK4

SK1

SK3 PL3

PL1

PL5

PL9

SK5

SK9

PL6 SK6

Bottom PCB

Rear PCB

Top PCB

Front PCB

Voltage Alarm Circuitry Clocks Ajustment Potentiometers

Alarm selection links Timers Alarm relay drivers

High Impedance detection circuit Earth Leakage detection circuit Power supply circuit

High Impedance current Pulse FET Earth Leakage dropper resistors


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6. BATTERY ALARM 315 The battery alarm 300 is offered in an alternative housing as a back of panel mounting case.

It is then designated Battery Alarm 315

The electronic circuitry, operation and connection terminal numbering is identical to those of the battery alarm 300 described above.

Only voltage ratings from 24 V to 125 V are available in this model.

Potentiometers for adjusting high and low voltage alarm levels and the high impedance level are accessible behind a removable transparent cover


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7. DIMENSIONS 7.1 Battery Alarm 300 case dimensions

7.2 Battery Alarm 315 case dimensions

battery alarm user manual

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