GE BA300 Commissioning Instructions page 6

Applications
For situations where batteries are located in unmanned substations it is important that the
security of the supply is maintained. This means, not only that the battery voltage is within
required limits, but that Earth Leakage is minimised and any latent faults in the battery and its
connections will not result in failure to initiate tripping when a heavy current is demanded.
The Battery Alarm is suitable for use on all batteries with an impedance exceeding 0.1Ω.
Connections
Figure 1 below shows how the Battery Alarm should be included in the system. The Battery
Alarm positive and Battery Alarm negative leads should be connected as near to the battery
terminals as possible via 2A rated fuses.
For safety reasons, the earth terminal must be connected to earth. If either the positive or
negative of the battery is earthed, the standard Battery Alarm 300 will indicate an earth fault
alarm. In the case when an earth relay is already fitted, a Battery Alarm 300 model without
earth fault is recommended.
Test Method for Battery Alarm
The unit can be tested using the equipment shown in Figure 2. With this set-up, carry out the
following tests:
WARNINGS
i) E(GND) is not connected to earth for this test. The metal backplate will be
at half the battery voltage, current limited to 5mA.
ii) Ensure that the 220µF capacitor is safely discharged using a suitable
resistor.
Optional
choke
Note: The Battery Alarm is shown in the energised state. Under healthy operating
conditions, the urgent relay is operated and the non-urgent relay is released.
Figure 1: External Wiring Diagram
2A FS1
Non-urgent
Urgent
11
10
E
12
2A FS2
Page 6
Busbars to
battery loads
3
1
2
6
4
5
To telemetry
8
7
9