Insulation testing after cable installation
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Power cables with a cross-sectional area of 150 square millimeters and a length of 30 meters have been laid from the distribution room to the power distribution box on the motor side. Now I want to test the insulation resistance of these power cables – how should I proceed? I’m using a megohmmeter. Some expert, please help!
1. Check that the megohmmeter is in good condition； 2. Disconnect the wiring at both ends of the power supply ； 3. Inter-wire insulation: Check the resistance value between each wire and every other wire ； 4. Wire-screen insulation: Insulation between the signal wire and the shield ； 5. Screen-to-screen insulation (split-screen cable): Measure the insulation between shields ； 5. Armored insulation: Resistance of the wire or main shield to the armor, and resistance of the armor to ground ； 6. Ground insulation: Measures the insulation to ground when all wires are short-circuited together. Generally, 1, 2, 3, and 6 are enough.
Simply, like with a new cable, use a multimeter to check it.