How an insulation multimeter works and how to operate it
Overview: An insulation multimeter is a functional instrument used by technicians 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 by conducting insulation resistance tests on conductors, electrical components, circuits, and devices.
Importance of insulation resistance measurement
Maintenance technicians use insulation resistance testing to minimize the probability of equipment failure or malfunction and maximize production efficiency. At the same time, it can also prevent the occurrence of dangerous accidents such as electric shock and fire, ensuring the personal safety of employees.
Insulation resistance measurement process
Before using an insulation meter for testing, technicians must first conduct basic voltage, current, and resistance measurements.
After the equipment is powered off, use a FLUCK insulated multimeter to determine the integrity of the windings or cables in the motor, transformer, and switchgear. Measure the insulation resistance and leakage current of the insulation material to generate an insulation resistance value, as shown in Figure 2.
Safe operation
(1) Before testing
1. Work on non energized circuits as much as possible, using appropriate locking/marking procedures
2. Assuming the tested circuit is live, use appropriate personal protective equipment and safety tools.
3. Remove all jewelry and stand on a rubber insulated school.
During testing
1. Do not connect the insulated common meter to live conductors or live equipment, and strictly follow the manufacturer's recommendations.
2. Turn off the tested equipment through an open circuit fuse, switch, or circuit breaker. Lock and label the tested device.
3. Disconnect branch wires, grounding wires, and all other equipment from the tested unit.
4. Before and after testing, discharge the conductor capacitance separately.
matters needing attention
1. Check all leakage currents through fuses, switching devices, and circuit breakers in the de excitation circuit. Leakage current can cause inconsistent readings and errors.
2. As the instrument will generate an arc when the insulation is damaged, do not use the insulation resistance tester in hazardous or explosive gas environments.
3. Do not use an insulation resistance tester on electronic devices.
4. Please use insulated rubber gloves with leather protection when connecting the test line.
Maintenance principle
(1) During device installation and updates
It will avoid wiring errors and defective equipment in the system, ensure high-quality installation, and prevent electric shock or equipment fire.
