Telephone System Installation and Maintenance Guide

170 Chapter 20 Replacing a power supply
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Preparing the system for maintenance
In most cases, if the power supply for the main unit is faulty, the system will already be shut down.
If this is the case, proceed to “Removing the power supply”. If you are replacing the expansion
unit power supply, or the system is still operating, perform the following procedure:
To shut down the system
1 Check for a recent backup of the BCM50 system programming.
2 If there is no recent backup, use Element Manager to back up the system data. For information
about backing up the system data, refer to the BCM50 Administration Guide (N0016868).
3 In Element Manager, from the Administration tab, click the Utilities folder to expand it.
4 Select Reset from the Utilities folder.
5 Click Reboot BCM50 System to reboot the system.
The BCM50 system begins the shutdown process.
6 Unplug the main unit, when the status and power LEDs go from solid green to flashing orange.
7 Continue to the next step, “Removing the power supply”.
Removing the power supply
Before you disconnect the power supply, read the warnings about connecting network lines in
“Wiring warnings” on page 103.
To remove the power supply
1 Remove the telephony and data networking lines from the BCM50 units. These lines include:
• the RJ-21 telephony connector on the main unit
• the ADSL line in the WAN port on a BCM50a main unit
• any analog telephone lines in the media bay modules (MBM) in the expansion units
• any digital telephone lines in the MBMs in the expansion units
2 Rotate the power supply retention clip to free the power supply cord.
3 Remove the power supply cord from the BCM50 unit.
4 Remove the power supply cord from the ac wall outlet.
If your system has a UPS, remove the power supply cord from the UPS socket.
Warning: Leakage currents
You must disconnect the telephony and data networking cables from the system before
disconnecting the power cord from a grounded outlet.