Nortel Networks BCM50 - Manual (Page 172)

172 Chapter 20 Replacing a power supply
NN40020-302
Preparing the system for maintenance
In most cases, if the power supply for the main unit is faulty, the system is already shut down. If
this is the case, proceed to
Removing the power supply on page 172. If you replace the expansion
unit power supply, or if the system is still operating, perform the procedure To shut down the
system on page 170.
Removing the power supply
Before you disconnect the power supply, read the warnings about connecting network lines in
Wiring warnings on page 105.
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.
5 Remove the power supply from the table, rack-mount shelf, or wall-mount bracket.
6 Proceed to Connect the new power supply on page 172.
Connect the new power supply
Before you connect the power supply, read the warnings about connecting network lines in Wiring
warnings on page 105.
Warning: Leakage currents
You must disconnect the telephony and data networking cables from the system before
disconnecting the power cord from a grounded outlet.