Description
61180043L2-5D 3
Battery Disconnect Protection Circuit
During battery operation a protection circuit disconnects battery from the main output when
battery voltage drops below 39 VDC, preventing over discharge. When AC returns, the main
output provides regulated –54 VDC, batteries recharge, and the system returns to normal.
Refer to “LED Indication”.
After the protection circuit initiates, the LEDs remain on (red), continuing to slowly drain the
battery. When battery voltage drops to 35 VDC, all load is removed from the battery. If AC
power will not be available for an extended period (several days), disconnect the battery to
prevent unnecessary discharge.
DC Over Voltage Protection
The PS/BC has a protection circuit that disables the rectifier to protect the load from a high
output voltage caused by rectifier failure. The backup battery or redundant PS/BC supports
the load in this instance. The over voltage event can permanently disable the PS/BC. Confirm
this by performing the following procedure:
1. Disconnect the PS/BC from the AC source.
2. Wait 30 minutes minimum.
3. After 30 minutes plug back into the AC source.
4. If the unit has recovered, the AC FAIL/UNIT FAIL/OVERLOAD LED will turn on green and the
unit returns to service. If the LED does not turn on green, replace the PS/BC.
Alarm Relays
There are two uncommitted alarm relays associated with PS/BC operation:
• AC Fail (ACF): Alarms if AC fails, the rectifier overloads, or the rectifier fails
• Battery Low Voltage (BV): Alarms if either or both battery voltage drops below 42 VDC
Fuse
A standard 5×20 mm 5-amp fuse adjacent to the AC power cord protects AC power feed
overload in case of rectifier failure.