Technical data

CORRECTIVE MAINTENANCE
CV ELECTRICAL POWER SYSTEM MAINTENANCE MANUAL 2A5A2-ELEC-MM-1-0 14
4.4 Measuring High Voltage
DANGER!
Shock hazard! Verify power to the unit is isolated before performing this
corrective maintenance procedure. This procedure exposes conductors
that carry high voltage sufficient to cause lethal electric shock.
When performing work in the CV power room, be aware of potential
exposure to high voltages sufficient to cause lethal electric shock.
Drawing References
7532934 Control van structure demarc panel – power
Special Tools
Digital MultiMeter (DMM), high voltage probe rated to at least 4000 VAC
Spare Parts
None
Preconditions
None
Procedure
1. Follow instructions in Section 6.2, General Notes, regarding hazmat
requirements, torque specifications, inspection of mounting hardware, and use of
Nylok® nuts, as applicable.
2. Perform the following steps in accordance with local requirements for SOC and
tag in/out, as applicable.
3. In the CV, at the
POWER DISTRIBUTION UNIT, set POWER BUS #1 (2A5A2-1B-EP01-1)
and
POWER BUS #2 (2A5A2-CB-EP01-2) to OFF.
DANGER!
Before disconnecting any cable, power must be turned off and locked out.
4. At the power demarcation panel, disconnect the cable. For the HPU boost
transformer, disconnect HPU power bus #1 cable (2A5/2A7-CBL-EPO1) or HPU
power bus #2 cable (2A5/2A7-CBL-EPO2). For the hotel boost transformer,
disconnect hotel power bus #1 cable (2A5/2A7-CBL-EPO3) or hotel power bus
#2 cable (2A5/2A7-CBL-EPO4).
5. Using a Digital MultiMeter (DMM) with a high voltage probe rated to at least 4000
VAC, clip the DMM probes to the test points.
6. Ensure that the clips and test leads do not contact each other or any conductor.
Position the DMM so that it can be read from several feet away.
7. Move non-essential personnel 10 feet from the open enclosure. Ensure that the
maintainer who will read the meter is clear and safely away from any conductors.
8. Restore HPU/hotel power.