Rockwell Automation 2100 CENTERLINE Low Voltage Motor Control Centers - Manual (Page 94)

94 Rockwell Automation Publication 2100-IN012E-EN-P - February 2012
Chapter 9 Maintenance
5. Periodically clean or replace the air filters depending on the environmental
conditions.
6. Check for the proper function and freedom of movement (no sticking or
binding) for the disconnect handle operating and defeater mechanisms.
7. Replace broken, deformed, malfunctioning, or badly worn parts or
assemblies.
8. Inspect unit bus-stab connections for wear or corrosion.
Wear and/or corrosion can increase resistance and cause an increased
temperature of the contact point, leading to failure. Replace bus stabs if
wear or corrosion is excessive. Lubricate bus stabs with NO-OX-ID grease
(catalog number 2100H-N18 or 2100H-N18T) before installing the unit
into the section.
9. Inspect current carrying parts such as fuse clips, knife blades of
disconnects, and line and load terminals of devices for discoloration,
corrosion, or other signs of wear or possible failure.
10. Check locking or interlocking devices for proper working condition.
11. Adjust, repair, or replace any device if necessary.
12. Check power contacts for excessive wear and dirt accumulation and
vacuum or wipe contacts with a soft cloth to remove dirt as needed.
Contacts are not harmed by discoloration and slight pitting. Contacts
should never be filed, as this could reduce the life of the contacts. Contact
spray cleaners should not be used, as they cause sticking on magnetic pole
faces or in operating mechanisms, interfering with the electrical continuity
of the contacts. Contacts should be replaced only after the silver has
become badly worn. Always replace contacts in complete sets to avoid
misalignment and uneven contact pressure.
13. Check for loose wire connections on power and control circuit terminals.
Loose connections can cause overheating, hot spots, or arcing faults that
could lead to equipment malfunction or failure. Replace any damaged
parts or wiring.
ATTENTION:
When working on or near energized electrical equipment, follow
established electrical safety-related work practices. Refer to NFPA
70E Standard for Electrical Safety in the Workplace.
To prevent injury or death to personnel lubricating disconnect switch
contacts, make sure the MCC power source(s) is disconnected and
the respective disconnect(s) is locked in the OFF/O position. For plug-
in units, remove the unit from the MCC.
To prevent personal injury or damage to equipment, make sure that
the unit handle operator is in the OFF/O position before removing the
unit.