Carrier Access Wide Bank 28 DS3 User Manual page 43

External Clock Connector. An external DS3 clock connector (75-ohm unbalanced BNC) is
provided for clocking the unit from an external 44.736 MHz timing source, when required.
Alarm Connector. The alarm contacts are on a 4-position wiring block connector. There are
contacts for a critical alarm and for a combined major/minor alarm. The contacts can be
programmed to be normally open or normally closed. One cable connector, which can be wired
to externally-powered alarm monitor or indicator, is provided with each Wide Bank 28 DS3. For
wiring information, see External Alarm Wiring on
Power Connectors. Power connections are made to the –48 VDC power connector input with a
three-position removable wiring connector. An 8-foot DC power cord is provided with each
Carrier Access Corporation 120 VAC to –48 VDC Power Converter/Battery Charger. There are
two independent power receptacles on the rear of the Wide Bank, labeled A and B. Power
connector A supplies –48 VDC to the power supply on Controller card A, and power connector B
supplies –48 VDC to the power supply on Controller card B. For wiring information, see Wiring
the Power Plugs on
The Controller cards are designed to provide power to each other if a power failure occurs. If only
power connector A has a power source plugged into it, the power converter for Controller card A
will supply power to the entire system including Controller card B. However, if Controller card A
is removed, Controller card B will no longer receive power. The same is true (in reverse) if only
power connector B has a power source.
WARNING!
RECEIVE POWER AND BOTH POWER CONNECTORS MUST HAVE A POWER SOURCE
PLUGGED INTO THEM
–48V
TWO
PROTECTION
Wide Bank 28 DS3 - Release 2.4
page 5-14.
F
OR REDUNDANT OPERATION BOTH
. I
T IS RECOMMENDED
POWER SOURCES BE INDEPENDENT TO MAINTAIN PROPER REDUNDANCY AND
.
page 5-12.
C
,
AND IS STANDARD PRACTICE
July 2004
Product Description
Connector Panel Interfaces
ONTROLLER CARDS MUST
,
THAT THE
2-7