Safety is a sense. No instrument or tools can guarantee safety. Only safe practice and quality tools can ensure the safety. When you are to do insulation resistance test there is risk of both human injury also the probable damage to the machine itself. So you should follow the safety tips while doing an insulation resistance test.
Safe procedure of insulation resistance test
01. Work on de-energized circuits whenever possible. Use proper lock-out/tag-out procedures. If these procedures are not in place or not enforced, assume the circuit is live.
03. Never connect the insulation tester to energized conductors or energized equipment and always follow the manufacturer’s recommendations.
04. Shut down the equipment to be tested by opening fuses, switches, and circuit breakers.
05. Disconnect the branch circuit conductors, grounded conductors, grounding conductors, and all other equipment from the unit under test.
06. Discharge conductor capacitance, both before and after the test. Some instruments may have automatic discharge functions.
07. Check for any leakage current through fuses, switches, and breakers on de-energized circuits. Leakage current can cause inconsistent and incorrect readings.
08. Don’t use an insulation tester in a dangerous or explosive atmosphere since the instrument can generate arcing in damaged insulation.
09. Use insulated rubber gloves when connecting the test leads.