Isolation/Insulation Test
Correction Code 44000100
Perform the isolation/insulation test when diagnosis requires verification that a circuit or component is properly isolated, or a cable has sufficient insulation.
Only technicians who have been trained in High Voltage
Awareness and have completed all required certification courses (if
applicable) are permitted to perform this procedure. Proper personal
protective equipment (PPE) and insulating HV gloves with
a minimum rating of class 0 (1000V) must be worn at all times a
high voltage cable, busbar, or fitting is handled. Refer to Tech Note
TN-15-92-003, High Voltage Awareness Care Points
for additional safety
information.
Special tools required for this procedure:
Part Number | Description |
1076921-00-B | Insulation Multimeter, Fluke 1507 (NA) |
1076921-00-A | Insulation Multimeter, Fluke 1587 (EMEA) |
1076921-01-B | Insulation Multimeter, Fluke 1508 (APAC) |
1130480-00-A | Test Probes, Slim, Fluke TP38 |
Procedure
- Inspect the condition of the HV rubber gloves and protective outer gloves. Do not use any PPE that is out of date, leaking, or otherwise compromised.
- Inspect the condition of the isolation/insulation tester that it is fit and functional. Do not use any equipment that has frayed or damaged probes, leads, connectors, or exposed metal.
- Install the probes to the tester.
- Set the tester to measure isolation/insulation MOhms (MΩ) scale.
-
Set the tester to the test
voltage appropriate for the component being measured.
-
HVAC PTC heaters and
refrigerant compressors - 250VCAUTIONTest voltages greater than 250V will damage PTC heaters and compressors.
- Charge ports only - 1000V
- All other components - 500V
NoteRefer to Toolbox article 6230600 for additional information. -
HVAC PTC heaters and
refrigerant compressors - 250V
- Put on the PPE.
- Set and hold the probe ends to the locations to be tested.
- Press the START/TEST button on the tester to begin the test.
-
Observe and remember the
measured isolation resistance/insulation resistance in MOhms (MΩ).
WarningDo not remove the probes from the test locations.
-
Release the START/TEST
button, or press a second time, (as appropriate) to end the test.
WarningDo not remove the probes from the test locations. Removing the probes prematurely prevents the tester from discharging the circuit under test. These videos demonstrate that without proper discharge, high voltages are present and dangerous.
-
Allow the tester to
discharge the circuit under test.
NoteFor some testers, a measured value will decrement to zero. This video demonstrates proper discharge after measurement.
-
Verify that there is no
indication on the tester of high voltage present in the circuit under
test.
NoteIndicators on the tester display might be:
- Lightning bolt icon
- TEST icon
- HV icon
- Attention icon
- LED lit
- Remove the probes from the test locations.
-
Set the tester to measure
high voltage DC.
WarningThe tester must not be set to measure isolation/insulation MOhms (MΩ).
- Set the probe ends to the same locations previously tested.
- If the voltage is greater than 10V continue to hold the probes to the test locations for an additional minute.
-
If after a minute, the
voltage is still greater than 10V and:
- The voltage is not gradually decreasing - Remove the test probes and escalate a toolbox session to region.Do not touch the component until the voltage is verified to be safe (10V or less).
- The voltage is gradually decreasing - Continue to hold the probes to the test locations until the displayed voltage is 10V or less.
- Remove the probes from the test locations.
- Remove the HV PPE.
- Refer to Toolbox article 6230600 for component expected isolation resistance specifications and additional information.