DS8000 Service Documentation Version 7.5

Checking customer ground continuity with customer CB off (wired)

Procedure

  1. Prepare the multimeter to measure 1.0 V ac or less. Measure the voltage on the female ground pin on each mainline power cable and building ground. Refer to Figure 1 or Figure 2For the top exit line cord feature, refer to Figure 3 and Figure 4.

    Is the voltage less than 1.0 V ac?

    • Yes, go to step 3.
    • No, continue at the following step.
    Figure 1. Three-phase delta mainline power connector at DC-UPS end
    Three-phase mainline power connector
    Figure 2. Single phase mainline power connector
    Single phase, mainline power connector
    Figure 3. Three phase mainline power connector (top exit line cord feature)
    Three phase mainline power connector (top exit line cord feature)
    Figure 4. Single phase mainline power connector (top exit line cord feature)
    Single phase mainline power connector (top exit line cord feature)
  2. Voltage is present at a customer outlet with the customer circuit breakers off.
    DANGER
    Inform the customer that even though the circuit breaker is off, voltage higher than 1.0 V ac is measured at the failing customer voltage outlet pins.

    Do not continue until the voltage is less than 1.0 V ac.

  3. Prepare the multimeter to measure 1.0 ohm or less of resistance.
  4. Measure the resistance between the female connector ground pin on each mainline power cable and the building ground.

    Is the resistance 1.0 ohm or less?

    • Yes, continue with the next section..
    • No, inform the customer. Do not continue until the resistance is 1.0 ohm or less.