Nortel DMS-100 Manual page 104

Recovering from a dead system in a SuperNode switch
Recovering from a dead system in a SuperNode switch
At the PDC
1 When you detect the power outage, remove all fuse holders from the PDCs.
Remove the fuse holder for the LCE talk batteries, TME talk batteries, and
PDC filter fuses.
2 The voltage of the feed that powers the system (-48 V dc or -60 V dc)
determines the next step.
3 When power is restored at the power plant for your office, notify power
maintenance personnel. The power maintenance personnel must verify that
an acceptable power level is restored for each PDC. At the rear of each PDC,
measure the dc voltage across the A feed bus and the battery return plate.
Repeat for the B feed bus. The power is restored when the voltage on is -48
V dc.
DANGER
Contact ETAS or your next level of support
In the event of a dead system, contact Emergency
Technical Assistance Services (ETAS) at Nortel, or your
next level of support, before you perform this procedure.
DANGER
Risk of electrocution
Do not touch the cabinet wiring. Contact with cabinet
wiring that is not shielded can result in electric shock.
Only qualified power maintenance personnel must perform
the voltage measurements in step 3.
Note: The location of the fuse holders in the fuse panel depends on your
office configuration. To locate the fuse holders, consult the fuse
assignment diagram for your office or contact the next level of support for
help.
If the system
uses -48 V dc
uses -60 V dc
Note: The system distributes power at the potential of -48 V dc. In
extreme conditions, like a commercial power failure, the operating voltage
can range from -43.75 V dc to -55.8 V dc.
If power
is restored
DMS-100 Family NA100 Recovery Procedures LET0015 and up
System level recovery procedures
Do
step 3
step 4
Do
step 6
2-57
(continued)