Tests and Maintenance Performed with the Control Unit Removed
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HAZARD OF IMPROPER LUBRICATION
Failure to follow these instructions can result in equipment damage.
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Once the control unit is removed, perform the following tests and maintenance:
Stab Assemblies—Inspect the stab assemblies (see Stab Assembly) for signs of arcing or overheating. Replace the disconnect assembly (FA/KA type circuit breakers) or the jaw connector assembly (B-, H-, J-, or L-frame circuit breakers) immediately if overheating has occurred. For replacement disconnect assemblies, see Section 14—Circuit Breaker and Fusible Switch Replacement.
Stab Assembly
Circuit Breaker or Disconnect Switch—Verify proper operation of the circuit breaker or disconnect switch. Inspect switch blades; if evidence of arcing or excessive heat is present, replace the switch assembly. Exercise the push-to-trip feature on the circuit breakers.
Operator Mechanism in the Tripped Position
Operator Mechanism—Verify proper operation of the operator mechanism (see Operator Mechanism in the Tripped Position). Test for proper ON, TRIP, OFF, and RESET positions (F-, K-, and Lframe circuit breakers) or ON, TRIP, and OFF positions (B-, H-, J-, M-, or Pframe circuit breakers). Verify proper door interlock operation.
Fuses—Inspect all fuses and fuse clips (see Inspecting Fuses). Replace any parts showing signs of overheating or arcing.
Inspecting Fuses
Starter Contacts—Check the starter contacts (see Starter Contacts). Replace any that are badly worn or pitted. (See the Schneider Electric Literature Lists for the appropriate instruction bulletin.)
Starter Contacts
Control Devices—Check for proper operation of starters, relays, timers, and other control devices (see Control Devices).
Control Devices
Overload Relay—Manually trip the overload relay to ensure proper operation (see Tripping the Overload Relay). Verify that the thermal unit is the proper size for the application. Refer to the thermal unit selection tables (Section 13—Thermal Overload Unit Selection).
Tripping the Overload Relay
Wiring and Electrical Connections—Verify that all electrical connections are correct; tighten them if necessary (see Tightening Electrical Connections). For any inaccessible electrical connections, please contact Schneider Electric Services. Also inspect all power and control wiring, replacing any wire that has worn insulation or shows signs of overheating or cracking.
Tightening Electrical Connections
Starter Interlocks—Check the mechanical interlocks on reversing, multispeed, or reduced voltage starters.
Barriers/Insulators—Inspect all insulators, braces, and barriers (see Manual and Automatic Bus Shutters); replace any that show signs of arcing damage, tracking, excessive heat, or cracking.
Special Units—Follow the manufacturer’s recommended maintenance procedures for special units (for example: drives, soft starts, and automatic transfer switches).