IBM eserver pSeries 690, Руководство по установке, Страница: 33 / 142

Step 9. Check the Outlets and the Power Source
CAUTION:
Do not touch the receptacle or the receptacle faceplate with anything other than
your test probes before you have met the requirements in below.
Do the following to ensure that the customer has provided the correct power to the
system:
__ 1. This system is equipped to use 200-240 V / 380-415 V / 480 V ac, three-phase.
Check that the correct power source is available.
__ 2. Have the customer locate and turn off the branch circuit breaker and attach tag
S229-0237, which reads “Do Not Operate.”
Note: All measurements are made with the receptacle faceplate in the normally
installed position.
__ 3. Some receptacles are enclosed in metal housings. On receptacles of this type,
perform the following steps:
a. Check for less than 1 volt from the receptacle case to any grounded metal
structure in the building, such as a raised-floor metal structure, water pipe,
building steel, or similar structure.
b. Check for less than 1 volt from receptacle ground pin to a grounded point in
the building.
Note: If the receptacle case or faceplate is painted, be sure the probe tip
penetrates the paint and makes good electrical contact with the metal.
__ 4. Check the resistance from the ground pin of the receptacle to the receptacle
case. Check resistance from the ground pin to building ground. The reading
should be less than 1.0 ohm, which indicates the presence of a continuous
grounding conductor.
Note: If measured impedance is greater that 1 ohm and the test instrument
used was a digital multimeter, verify that the grounding impedance is
correct by using an appropriately approved ground-impedance tester.
__ 5. If any of the checks made in substeps 2, 3 and 4 are not correct, ask the
customer to remove the power from the branch circuit and make the wiring
corrections; then check the receptacle again.
__ 6. Check for infinite resistance between the phase pins. This is a check for a
wiring short.
CAUTION:
If the reading is other than infinity, do not proceed! Have the customer
make necessary wiring corrections before continuing. Do not turn on the
branch circuit CB until all the above steps are satisfactorily completed.
__ 7. Have the customer remove tag S229-0237, which reads “Do Not Operate” and
turn on the branch circuit breaker.
Chapter 2. Installing the pSeries 690
17