IBM 7014 T00, Manual

Page: 56 / 196

DANGER: If the circuit breakers controlling the device have not been removed from the PDP,
ensure they are in the “off” position. After the circuit breakers are turned off, be sure there is a tag
or label (lockout/tagout) over the circuit breakers to indicate that the power source is turned off
intentionally.
DANGER:
If you do not disconnect the -48V DC power sources to the rack the cable removal must be
performed by a qualified electrician.
Procedure
1. Remove the cable channel cover.
To remove the cable channel cover, do the following:
a. Loosen the four retaining screws.
b. Align the larger openings in the cover with the retaining screw heads.
c. Lift the cover up to clear the retaining screws and remove it.
2. Remove the PDP top cover. To remove the PDP top cover, do the following:
a. Remove the four retaining screws.
b. Remove the PDP cover.
3. If the cable to be removed is on the B-side only, go to step “9” on page 42
DANGER: Turn off the -48V DC A power sources that are connected to the PDP.
4. After the -48V DC A power sources is turned off, be sure there is a tag or label over the A power
source switch or fuse (lock-out/tag-out) to indicate that the A power source is turned off
intentionally.
5. Remove the A-side plastic bus bar covers from the PDP. To remove the A-side plastic bus bar covers
from the PDP, remove the two retaining screws from the A-side cover.
6. Disconnect the DC power cable for power supply 1 (A) from the PDP. To disconnect the DC power
cable for power supply 1, do the following:
a. Disconnect the -48V DC wire from the circuit breaker lug on the A side. Reinstall the nuts and
washers onto the studs.
b. Disconnect the -48V return wire from the position matching the circuit breaker position on the
PDP return, i.e. if the -48V DC wire was connected to circuit breaker A3, the return wire should be
disconnected from the A3 position on the return bus bar. Reinstall the nuts and washers onto the
studs.
c. Disconnect the ground wire to the matching position on the copper ground bar. Reinstall the
screws and washers into the copper ground bar.
d. Disconnect the DC power cable from power supply 1 (A) and remove it.
e. If there are additional units or power supplies to be disconnected from the A side of the PDP,
repeat step “6” on page 42.
7. After all the A-side cables are removed, position the cover over the A-side connections and reinstall
the two retaining screws.
8. Restore the -48V DC A-side power to the PDP.
9. If you must remove cables from the B side, continue with the next step. Otherwise, go to step “17”
on page 43.
DANGER:
If there are cables connected to the B side, turn off the -48V DC B power sources that are
connected to the PDP.
42 Power Systems: Racks and rack features