Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control - Manual (Page 177)

Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014 177
Preventative Maintenance Schedule Appendix C
Operating Mechanisms
Check for proper functioning and freedom from sticking or binding. Replace any
broken, deformed or badly worn parts or assemblies according to individual
product User Manuals. Check for and securely re-tighten any loose fasteners.
Lubricate, if specified in individual product instructions. Many devices are
factory lubricated. If lubrication during use or maintenance of these devices is
needed, it will be specified in their individual product instructions and/or User
Manual. Note: Allen-Bradley magnetic starters, contactors and relays are
designed to operate without lubrication. Do not lubricate these devices, because
oil or grease on the pole faces (mating surfaces) of the operating magnet may
cause the device to stick in the "ON" mode.
Contacts
Check contacts for excessive wear and dirt accumulations. Vacuum or wipe
contacts with a soft cloth if necessary to remove dirt. Contacts are not harmed by
discoloration and slight pitting. Contacts should never be filed, as dressing only
shortens contact life. Contact spray cleaners should not be used as their residues
on magnet pole faces or in operating mechanisms may cause sticking and can
interfere with electrical continuity. Contacts should only be replaced after
contact face material has become badly worn. Always replace contacts in
complete sets to avoid misalignment and uneven contact pressure.
Vacuum Contactors
Contacts of vacuum contactors are not visible, so contact wear must be checked
indirectly. Vacuum bottles should be replaced when:
1. The contactor wear indicator line shows need for replacement, or
2. The vacuum bottle integrity tests show need for replacement.
Replace all vacuum bottles in the contactor at the same time to avoid
misalignment and uneven contact wear. If the vacuum battles do not require
replacement, check and adjust over-travel to the value listed in the product User
Manual.
Power Cable and Control Wire Terminals
Loose connections in power circuits can cause overheating that can lead to
equipment malfunction or failure. Loose connections in control circuits can
cause control malfunctions. Loose bonding or grounding connections can
increase hazards of electrical shock and contribute to electromagnetic
interference (EMI). Check the tightness of all terminals and bus bar connections
and tighten securely any loose connections. Replace any parts or wiring damaged
by overheating, and any broken wires or bonding straps. Refer to the User Manual
for torque values required for power cable and bus hardware connections.