Comdial G0408 Manual page 86

Digital Telephone System
Connecting The Battery Back Up Assembly
The common equipment provides an interface connector for the connection of an optional
external battery assembly.
Be sure that the AC power cord is connected to the electrical outlet before connecting an
external battery assembly to the common equipment interface connector. This ensures that
internal protection circuitry is operating to prevent damage that could result from improper
connection.
The external battery assembly provides a minimum of one hour of operation should the AC
power to the system be interrupted. The assembly has a 15 ampere-hour current rating and is
fused with the following vaue: 4A 250V 3AG type.
The external battery assembly may include batteries from either of the following suppliers:
• Model PS-12150 from Power-Sonic Corporation, Redwood City CA, 94032
• Model PE12V15 from GS PORTALAC, City Of Industry CA, 91748
The minimum battery backup time for a fully configured system can be calculated using the
formula:
Back Up Time (in hours) =
K (Constant) =
15 = ampere-hours
N = total number of stations
Example:
Assume that a G1632 system plus two GM408 modules are installed along with the optional
battery assembly to provide back-up power.
Back up time =
2 – 56 Installing The DSU
1 + [(0.1) (N)]
0.9 for G0408 with or without a GM408 module
0.8 for G0816 with or without GM408 modules
0.8 for G1632 with or without GM408 modules
(0.8) (15) 12
=
1+[(0.1) (48)] 5.8
CAUTION
K(15)
= 2.1 Hours
IMI66–107