GHX-308A/616
HYBRID KEY TELEPHONE SYSTEM
Http://suryawardana.com
20
3.17 BATTERY INSTALLATION
A separate external 24 Volt DC battery package must be provided and selected to ensure the proper back-up time during
power outage. 24 VDC(normally two 12 VDC batteries) package with a 20 Ampere hour rating is considered maximum.
It is recommended that maintenance-free gel-type batteries be used. The following must be considered when connecting
batteries.
A. Batteries are to be placed in a limited access room or cabinet with adequate ventilation to dissipate any battery gases
that may be present.
B. The batteries are to be installed in accordance with Article 480 of the National Electrical Code (NEC) in U.S.A. or any
other applicable codes.
C. A battery rack or case should be used to secure the batteries to prevent tipping or any movement that could cause
spilling of battery acid or shorting of terminals.
The arrangement should protect against all hazards such as fire, spark, heat, gas fumes and accidents.
D. Use the shortest length of flexible cord type that will comply with the National Electrical Code to connect batteries and
the KSU. The cable should be located, routed and clamped(strain relief) in such a way as to prevent the batteries
from moving should the cables be moved.
E. A 12 Amp 32V mininmum fuse or a 12 Amp DC instantaneous tripping circuit breaker should be installed. Locate it at
batteries “in line” with the battery negative lead to protect the battery from damage.
F. See [Figure 3-9] for wiring considerations. DC input wire size should be sufficient to restrict voltage drop to 0.5 volt or
less at rated input current between the battery and the KSU. The loop length is the sum of the lengths of the negative
and positive leads. Use wire sizes recommended by the National Electrical Code and/or local regulations.
(CN230 : External Battery Terminal)
CN230
MBU
FUSE
(5A/250V)
12VDC
12VDC
[Figure 3-9] BATTERY CONNECTION
3.18 MEMORY BACK-UP SWITCH
To protect the user database from being lost during System power failure, the short pin of connector “CN224” on the
MBU should be moved “OFF” to “ON” position after Admin programming. (refer to Figure 3-2)