Rockwell Automation Publication 2100-IN012D-EN-P - September 2010
75
Final Checklist Before Energizing
Chapter
7
13.
Manually exercise all switches, control auxiliary switches, circuit breakers,
their respective operators, unit interlocks, trip mechanisms (test by
pushing the ‘Push to Trip’ button), and any other operating mechanisms to
verify proper operation.
14.
Check timing relay settings as required.
15.
Check the vents and fans.
a. Check all vents to ensure they are free from obstructions.
b. Check all fans, used for forced air cooling to ensure the shaft rotates
without obstructions.
c. Check that filters are in place and clean, and set up an in-house program
for scheduled cleaning or replacement.
If you have an MCC with arc-resistant design features, if a unit has been
provided with arc resistant baffles over door vents and fans, these baffles
must be fastened securely in place in order to maintain the arc resistant
capabilities of the MCC. Do not install any type of filter in place of, or
in addition to, the arc resistant baffles.
16.
Check all current transformers for proper polarity and ensure their
secondaries are not ‘open’, but are either connected to their respective
devices or ‘shorted.’
17. Recheck that all barriers and parts that may have been removed during
installation have been reinstalled.
Refer to your barrier checklist, see
step
18.
Before closing the enclosure and/or individual units, remove all tools,
metal chips, scrap wire and other debris from the MCC interior.
If there is an accumulation of dust or dirt, clean out the MCC using a
brush, vacuum cleaner or clean, lint-free rag.
Do not use compressed
air - it will redistribute contaminates on other surfaces.
19.
Conduct an electrical insulation resistance test to verify the MCC wiring
integrity.
Conduct this test using an insulation resistance tester (megger) with a
potential of 500...1000V. This megger test should be conducted phase-to-
phase, phase-to-ground, and when applicable, phase-to-neutral on the
MCC buswork. The test should be conducted with all of the switches or
circuit breakers in the open or OFF/O positions. Typical insulation
resistance values are 50 M
Ω
or greater.
ATTENTION:
Current transformer secondaries should not be
‘open’. To avoid possible injury and electrical shock to personnel,
do not energize a current transformer with its secondary open.
ATTENTION:
When conducting an electrical insulation resistance
test, isolate equipment sensitive to high test voltages, such as
meters, solid state devices, motor winding heaters, and capacitor
units.
