HVAC Procedure and Performance Guide

TASK: Install motor contactor

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Motor contactor must be installed according to manufacturer’s specifications.  Contactor must be securely mounted, electrical connections must be mechanically secure and electrical continuity must be established.  Contacts must be rated for voltage and current requirements.  Contacts must be aligned and must operate with minimum arcing.  Applicable safety procedures must be followed.


  1. Review job order, manufacturer’s specifications and equipment nameplate data.
  2. Determine size and type of contactor, contact rating and coil voltage required.
  3. Collect tools, equipment and materials.
  4. Put on safety and protective equipment and apparel.
  5. Disconnect electrical power to equipment.
  6. Remove old contactor and coil.
  7. Verify that contactor is suitable replacement.
  8. Mount new contactor and connect to wiring according to specifications.
  9. Install and connect coil according to specifications.
  10. Energize coil and close contacts.
  11. Inspect contacts and adjust alignment as required.
  12. De-energize coil.
  13. Reconnect electrical power.
  14. Verify that voltage supplied to contactor is correct.
  15. Start equipment and check contactor operation; verify that device operates correctly.
  16. If equipment does not operate to specifications, troubleshoot and make required adjustments and repairs.
  17. Leave equipment in required operating status.
  18. Remove safety and protective equipment and apparel.
  19. Gather tools, equipment and leftover materials and leave work site clean.