Use and Precautions of Insulation Resistance Tester
1 Selection of Insulation Resistance Tester: Choose an insulation resistance tester with appropriate rated voltage. The rated voltage of the insulation resistance tester should be selected based on the rated voltage of the equipment under test. If the rated voltage of the insulation resistance tester (i.e., the DC voltage of its internal power supply) is too high, it may damage the insulation of the equipment under test during testing; if the rated voltage is too low, the measured results cannot reflect the insulation resistance of electrical equipment under the working voltage. Generally, regulations stipulate that when measuring equipment with a rated voltage below 500V, an insulation resistance tester of 500-1000V should be used; for rated voltages above 500V, an insulation resistance tester of 1000-2500V should be used.
2 Usage of Insulation Resistance Tester
①Before use, check whether the pointer's "0" and "∞" positions are correct. The check method is: first open the "L" and "E" terminals, place the insulation resistance tester on a proper horizontal position, and after shaking the handle to the generator's rated speed (generally 120r/min), the pointer should point to the "∞" position. If it cannot reach "∞", it indicates that the test leads have poor insulation or the insulation resistance tester itself is damp. Use a dry and clean soft cloth to wipe the insulation between the "L" and "E" terminals. If necessary, place the insulation resistance tester on an insulating pad. If it still cannot reach the "∞" value, replace the test leads. Then short-circuit the "L" and "E" terminals, gently shake the generator, and the pointer should point to the "0" position. If the pointer does not point to zero, it indicates that the test leads are not connected properly or there is a problem with the insulation resistance.
Note: The above information and technical parameters are compiled and released by Yangzhou Dairui Electric Co., Ltd.
