IBM eserver pSeries 690 Installation Manual page 36

__ 8. With an appropriate meter, verify that the voltage at the outlet is correct.
__ 9. Verify that the grounding impedance is correct by using the ECOS 1020, 1023,
__ 10. Have the customer turn off the branch circuit breaker and attach tag
20
pSeries 690 Installation Guide
Note: If your power source does not have a standard receptacle, check for
voltage using local procedures.
Measure for appropriate voltages between phases. If no voltage is present on
the receptacle case or grounded pin, the receptacle is safe to touch.
Note:
v For 200-240 V the acceptable phase-phase voltage measurement
range is 180-254 V.
v For 380-415 V the acceptable phase-phase voltage measurement
range is 342-440 V.
v For 480 V the acceptable phase-phase voltage measurement range is
432-509 V.
B7106, or an appropriately approved ground impedance tester.
S229-0237, which reads "Do Not Operate."