84 Rockwell Automation Publication 2100-IN012G-EN-P - August 2016
Chapter 7 Final Checklist Before Energizing
If there is an accumulation of dust or dirt, clean out the MCC by using a
brush, vacuum cleaner, or clean, lint-free rag. Do not use compressed
air; it redistributes contaminates on other surfaces.
19. Conduct an electrical insulation resistance test to verify the MCC
wiring integrity.
Conduct this test by using an insulation resistance tester with a potential
of 500…1000V. Conduct this insulation resistance test phase-to-phase,
phase-to-ground, and when applicable, phase-to-neutral on the MCC
buswork. Conduct the test with all switches or circuit breakers in the
open or OFF/O positions. Typical insulation resistance values are
50 MΩ or greater.
Next, check the field wiring; for example, motor cables and incoming
line cables. Insulation resistance values are affected by temperature,
humidity, or dampness, which can cause a considerably lower insulation
resistance reading. If the insulation resistance values are below 1 MΩ
(for example, affected by dampness, temperature, or humidity) or the
MCC has been stored in a damp or humid area, we recommend that the
equipment be dried out. Dry out the motor cables by injecting a low
voltage current or by using space heaters.
Once the equipment is dry, repeat the insulation resistance test. The
minimum value for insulation resistance on a new installation at startup
or energizing is 1 MΩ. Record these readings in the Insulation
Resistance Reading Recording Table. Use this table to record additional
insulation resistance readings during regular maintenance periods.
20. Check that all arc-resistant parts are installed.
See ArcShield Components
for more information.
21. Check that all unit latches are secure.
See Door Latch Position Diagrams
for more information.
22. Check that all section closing plates are in place.
23. Check that any SecureConnect units are properly installed.
See SecureConnect Unit Checklist
for more information.
24. Close and latch all doors, making certain that no wires are pinched.
Certain applications can have latch requirements different from those
provided. If you have questions regarding proper latching, contact
Rockwell Automation LV MCC Technical Support at 1.440.646.5800
and follow the prompts to Allen-Bradley > Low Voltage Motor Control
Centers > Post Shipment Support.
Refer to the following illustrations for various latch placements.
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.
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