GE P50 Agile P253 Technical Manual page 275

P50 Agile P253
2.2 Changing the Battery
The P253 relay has a battery to maintain status data and the correct time when the auxiliary supply
voltage fails.
The data maintained includes event, fault and disturbance records and the thermal state at the time of
failure. The battery periodically needs changing if there is a low battery condition, to ensure reliability.
The lithium coin battery is located on the CPU PCB.
Caution:
2.2.1 Replacing the Lithium Coin Battery.
1. Remove the relay cover by loosening the screws as shown in figure below.
Figure 1: Removal of relay cover
P253/EN M/C
Before carrying out any work on the equipment you should be familiar with
the contents of the Safety Section or the Safety Guide Pxxx-SG-4LM-2 and
the ratings on the equipment's rating label.
12 Maintenance and Troubleshooting
12-5