Main Power Loss; Module Power Supply Failure - Nortel Meridian 1 General Maintenance Information

Main power loss

The system monitor receives status and control signals from the external
power system. The system monitor then generates system messages that
indicate the status of main and reserve power supplies.
You can connect a reserve (back-up) power supply to the Meridian 1: either
an uninterruptible power supply (UPS) for AC-powered systems or reserve
batteries for DC-powered systems. If the main source of external power is
lost, power to the system is maintained by the UPS or reserve batteries.
If the main power supply is lost, the system monitor generates a major alarm.
The NT8D22 System Monitor also generates system messages to indicate the
system is running on reserve power.

Module power supply failure

There are four types of module power supplies:
• common equipment (CE) power supply
• common/peripheral equipment (CE/PE) power supply
• peripheral equipment (PE) power supply
• ringing generator
The NT8D22 System Monitor handles complete or partial failures in a
module power supply as follows:
• If the output voltage is higher than the threshold for +5 volts, the affected
power supply shuts down, the column LED lights, and a system message
is sent.
• If the output voltage is higher than the threshold for other than +5 volts,
power for only that voltage shuts down in the affected power supply, the
column LED lights, and a system message is sent.
• If the output voltage is lower than the threshold for any voltage, power
for only that voltage shuts down in the affected power supply, the column
LED lights, and a system message is sent.
• If the input voltage is lower than the threshold, the affected power supply
shuts down and then recovers when the input level recovers.
Hardware maintenance tools
Meridian 1 General Maintenance Information
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