IBM RS/6000 SP, Maintenance Information

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5. Now have customer switch off primary power to this frame from an external circuit breaker.
6. Verify that there is no power present by repeating the measurements made in Step 2. If power is still
present, inform customer of this fact and return to Step 4.
7. Now that the proper circuit breaker has been located, install a lock on this circuit breaker to lockout
the circuit breaker, OR if a lock is not available, attach a DO NOT OPERATE tag (S229-0237) directly
to the circuit breaker.
8. You may now perform maintenance on primary power components per the instructions.
Lockout/Bagout Procedure for PDU
This may be used as an alternative to the Lockout/Tagout Procedure to ensure that no power is present in
the machine, and that primary power can not be accidentally applied. This procedure is also referenced as
required by the MAPs.
1. Use a multimeter with the pair of high-voltage probes (part number 93F2731). Set the multimeter to
the highest ac voltage setting.
2. The following measurements are to be taken at the ac filter (located inside the rear cover at the
bottom of the frame). Measure phase-to-phase ac voltage between test points O1 and O2. Repeat
measurement for test points O1 and O3. Repeat measurement between test points O2 and O3.
3. The purpose here is to guarantee that initially primary power is present at the test points. If the volt-
ages measured in Step 2 indicate that primary power is not present, have customer switch on power
for this frame, then go back to Step 2.
4. Switch off frame circuit breaker (located inside rear cover near bottom) to disengage ac power inside
frame.
5. Now locate plug for this frame, and remove plug from receptacle.
6. Verify that there is no power present by repeating the measurements made in Step 2. If power is still
present, check with customer or other maintenance personnel before reconnecting plug from Step 5.
Return to Step 5 to locate the correct plug.
7. Now that the correct plug has been removed from the receptacle, install a safety lockout bag (part
number 74F9606) over the plug and lock the bag closed.
8. You may now perform maintenance on primary power components per the instructions.
Chapter 1. Maintenance Analysis Procedures (MAPs)
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