HVAC Procedure and Performance Guide

TASK: Connect pressure switch

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Antishort-cycle timer must be installed according to manufacturer’s specifications. Connections must be mechanically secure and electrical continuity must be established.  Device must prevent compressor restart before pressure equalization after previous shutdown. Applicable safety procedures must be followed.


  1. Review job order and manufacturer’s specifications.
  2. Determine required voltage, current rating and cycle time for timer.
  3. Collect tools, equipment and materials.
  4. Put on safety and protective equipment and apparel.
  5. Disconnect electrical power to equipment.
  6. Remove old timer.
  7. Verify that new timer is a suitable replacement.
  8. Mount new timer and make electrical connections according to specifications.
  9. Reconnect power to system and verify that correct voltages are available.
  10. Start system and check operation.  If timer is adjustable, make required adjustments.
  11. If equipment does not operate to specifications, troubleshoot and make required adjustments and repairs.
  12. Leave system in required operating status.
  13. Remove safety and protective equipment and apparel.
  14. Gather tools, equipment and leftover materials and leave work site clean.