Checking rack power system ground continuity (wired)
Before you begin
Attention: Use an IBM-approved analog multimeter. Do not use a digital meter.
Procedure
Repeat the following steps for each rack that you are installing.
Switch off the customer circuit breaker that supplies the AC voltage to the mainline power
cables.
CAUTION:
Do not connect the mainline power cables until instructed to do so.
Attention: Use lockout and tagout procedures as defined in
the Electrical Safety for IBM® Customer
Engineers.
Verify the CB1 main line
switch on the rear of each
DC-UPS is set to Off (down). Refer to Figure 1 or Figure 2.
Figure 1. Location codes for the DC-UPS (Models 98x and 8xE,
single-phase power) (rear)
Figure 2. Location codes for the DC-UPS (Models 98x and 8xE, three-phase
power) (rear)
Verify the DS8000® mainline power cables
are not connected to the customer power.
Verify that the mainline power cables are connected to the DC-UPS.
Prepare the multimeter to measure 0.1 Ohm or less resistance.
Place one lead of the multimeter on the green and yellow wire at the customer end of each
mainline power cable. Place the other lead on the conductive metal of each DC-UPS DSU enclosure. Refer to Figure 3.
Figure 3. Using a multimeter to measure Ohm resistance
Disconnect the DS8000 mainline power
cables from each DC-UPS input power connector.
Twist the lock ring (single-phase) or push the connector handles
away from you (three-phase) to release the connector.
Instruct the customer to call a licensed electrician to connect each wired mainline power cable
to the customer mainline power source.
The mainline power cables of this rack must be connected to the customer's mainline power source
by a licensed electrician. The mainline power cable cannot be modified in any way.
Table 1. Mainline power cable wire color codes ("wired" configurations)
Three-phase wire color code (3-phase high voltage (380
- 415 V), 32A)
Single-phase wire color code (1-phase, 200-240V phase to neutral,
63A)
