Insulation multimeter working principle and operation procedure
Overview: The insulation multimeter is a functional instrument used by technicians to perform insulation resistance tests on conductors, electrical parts, circuits and devices to: verify the quality of electrical equipment, ensure that the equipment meets regulations and standards, determine changes in equipment performance over time, and determine the cause of faults.
Importance of Insulation Resistance Measurement
Maintenance technicians use insulation resistance testing to minimise the chance of equipment failure or breakdown and maximise productivity. At the same time, it can also eliminate the occurrence of electric shock, fire and other dangerous accidents, to protect the personal safety of employees.
Insulation resistance measurement process
1. Before testing with an insulation utility meter, technicians should first perform basic voltage, current and resistance measurements.
2. After the equipment is powered off, use a FLUCK insulation multimeter to determine the integrity of the windings or cables in motors, transformers and switchgear. Insulation resistance measurements and leakage current measurements are made on the insulating material to produce an insulation resistance value.
Safe Operation
(i) Before testing
1. work on uncharged circuits wherever possible, using appropriate lockout/tagout procedures
2. Assume that the circuit under test is energised and use appropriate personal protective equipment and safety tools.
3. Remove all jewellery and stand on a rubber insulated sook.
(ii) During the test
1. Do not connect the insulated utility meter to live conductors or live equipment and strictly follow the manufacturer's recommendations.
2. Switch off the equipment under test by means of an open circuit fuse, switch or circuit breaker. Lock and tag the unit under test.
3. Disconnect open circuit conductors, grounding conductors, and all other equipment from unit under test.
4. Discharge conductor capacitance before and after testing.
