Hi-pot and megger test, Start-up procedure, Contactor inspection – Rockwell Automation 1512A MV Controllers, 400A One-High Cabinet, Standard and Arc-Resistant Enclosure User Manual
Page 42: Preliminary checks, Hi-pot and megger test start-up procedure, Contactor inspection preliminary checks
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Rockwell Automation Publication 1512A-UM100F-EN-P - May 2013
Chapter 4
Common Installation
Hi-Pot and Megger Test
Insulation integrity should be checked before energizing medium voltage
electrical equipment. Use a high voltage AC insulation tester or a Megger for this
test. If a Megger is used, a 5000V type is recommended.
Insulation can be tested from phase to phase and from phase to ground. The
recommended level for AC Hi-Pot testing is (2 X V
LL
) volts, where V
LL
is the
rated line-to-line voltage of the power system. The leakage current must be less
than 20 mA. Record the result for future comparison testing.
If a Megger is used, it should indicate 50,000 M
Ω
or greater if the unit is isolated
from the line and the motor. If the unit is connected to a motor, the Megger
should indicate 5000 M
Ω
or greater (phase to ground).
Start-up Procedure
Contactor Inspection
See Publication
or
formation on
pre-energization inspection, vacuum bottle integrity test and insulation resistance test.
Preliminary Checks
Verify the following:
• Contactor current and voltage ratings are correct for the attached load;
• Control voltage is correct;
• Settings for protective relays;
• Heater elements (if provided) in overload relay are secure and undamaged;
• Equipment grounding;
• External power and control connections match electrical diagrams;
• All hardware is correctly reinstalled and torqued to specifications (refer
Recommended Torque Values on page 2 of Chapter 1
);
• All barriers are replaced to correct positions;
ATTENTION: Exercise caution when performing high voltage tests on the
equipment. Failure to do so may result in electric shock causing severe burns,
injury or death.
ATTENTION: Disconnect power factor correction capacitors (if so equipped)
before performing the Hi-Pot test. Failure to do so may result in personal injury
or damage to the equipment. See Power Lockout Procedure (refer to
) for information on dissipating any stored
power in the capacitors.
ATTENTION: Remove all primary fuses for the control power transformer and/
or the potential transformer. Failure to do so may cause damage to the
equipment during the Hi-Pot test.