Periodic Inspection and Maintenance
Perform periodic inspection and maintenance of bus and incoming line lug connections at least annually or more frequently if indicated by service conditions and your established maintenance policy.
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Inspect the bus and line compartment connections for any signs of overheating. Discoloration and flaking of insulation or metal parts are indications of overheating.
NOTE: If overheating occurs, be sure all conditions that caused the overheating have been identified and corrected. Loose or contaminated connections can cause overheating. -
Replace bus bars and terminal lugs that display pitting, corrosion, or discoloration resulting from high temperatures or having been subjected to short circuit conditions.
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Tighten any loose connections found. See Initial Maintenance for information on bus and incoming line compartment connections.
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Bus bar and other joints that were tightened during initial maintenance and do not display signs of overheating or other signs of loosening do not need to be retightened.
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Inspect all insulating materials. Before re-energizing the MCC, replace insulators showing any visible damage (such as cracks).