HVAC Procedure and Performance Guide

TASK: Measure resistance in electrical circuit

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Resistance must be correctly measured in specified circuit. Test device must be calibrated, connected and operated according to manufacturer’s specifications.  Applicable safety procedures must be followed.


  1. Review manufacturer’s specifications.
  2. Collect tools, equipment and materials.
  3. Put on safety and protective equipment and apparel.
  4. Locate specified circuit and correct test points using wiring diagrams.
  5. Disconnect electrical power to equipment.
  6. Remove access cover(s).
  7. Set up, calibrate and connect meter according to instruction manual.
  8. Measure resistance and record findings.
  9. Disconnect meter and reconnect circuit.
  10. Replace access cover(s).
  11. Leave equipment in required operating status.
  12. Remove safety and protective equipment and apparel.
  13. Gather tools, equipment, and leftover materials and leave work site clean.