DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-376CARR-POW (Carrier Power Supply)
9
Figure 9-21. Power Distribution Unit (J58890CH-1)
Power Backup
The small battery is at the center rear of the Mult i-Carrier Cabinet. This eight Amp
Hour (AH) battery is fused for short c ircuit protection and is charged b y the
J58890CH-1. The batteries also contain a thermal sensor that changes the
charging voltag e depending on battery temperature.
The small batteries provide short-term b attery holdover. If AC po wer fails, 48
VDC batteries power the system for 10 second s in a PPN cabinet, for 15 second s
in an EPN cabinet, and for 10 minutes in the co ntrol carrier in a standard
reliability system. The batteries also provid e system power for five minutes in the
control carrier in high and critical reliability systems, and for 10 minutes in the
expansion control carrier in th e “A” position of an EPN cabinet (Release 5r only).
Figur e 9-2 2 shows the small battery asse mbly.