User manual

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2201 Rack Chassis/2200R Redundant Card Canoga Perkins
3.4.2 Dual Power Supply Failure Alarm
When dual power supplies are employed in the 2201, the backup supply will continue
to power the modems after a failure of the other supply. Press the “Alarm Reset”
button to disable the audible alarm; the “Unit A Fail” or “Unit B Fail” indicator will
stay lit until the defective power supply is removed from the system and replaced.
The failed supply may be removed from the 2201 and replaced without taking the
modems out of service. The power supply line cord must be removed, as well as the
secondary supply lines to the power supply monitor PC card. The failed power
supply may then be removed from the front of the rack mount unit.
3.4.3 Power Supply Remote Failure Alarm Contact
The 2201 provides an external alarm contact. This floating relay contact is incorpo-
rated into the power supply monitor PC card. Access to this circuit is via a two-
position pluggable terminal strip directly below the power input connectors on the
2201 backplane circuit board.
The standard factory configuration for this alarm relay is a “normally open” condi-
tion. There is a jumper setting on the power supply monitor board to provide a “nor-
mally closed” condition (W1 for “normally closed,” W2 for “normally open”).
The standard factory setting of the remote alarm function is to activate the relay
contacts whenever a power supply (either “A” or “B”) has failed, or if power is
completely lost. This relay will not return to normal until the problem is corrected.