Project Description
How does insolution resistance test work. The moving coil 2 is connected in series with the positive terminal of the hand-cranked generator through a current-limiting resistor. The measured insulation resistance R is connected between the “line” and “ground” of the insulation resistance meter, and is connected in series with the moving coil 1 and the generator. The dotted line outside the “line” terminal button is the protective ring, which acts as a shield, and is connected to the negative end of the hand-cranked generator.
When measuring Rx, with the change of Rx, I1 changes, while I2 is basically unchanged. When Rx tends to 0, I1 is at the maximum, and the pointer deflects to the maximum position, which is the “0” position, under the action of the rotating torque and the reaction torque. When Rx tends to ∞, I1 tends to 0, and the pointer deflects to the minimum position under the action of the reaction torque, that is, the “∞” position. Therefore, the insulation resistance meter can measure the resistance between 0 and ∞.
When the insulation resistance tester is working, it generates high voltage by itself, and the measurement object is electrical equipment, so it must be used correctly, otherwise it will cause personal or equipment accidents. Make the following preparations before use:
(1) Before measurement, the power supply of the equipment under test must be cut off and short-circuited to ground. Never allow the equipment to be charged for measurement to ensure the safety of people and equipment.
(2) For equipment that may induce high voltage, this possibility must be eliminated before measurement can be performed.
(3) The surface of the measured object should be cleaned to reduce the contact resistance to ensure the accuracy of the measurement result.
(4) Before measuring, check whether the insulation resistance meter is in normal working condition, mainly check its “0” and “∞” two points. That is, shake the handle to make the motor reach the rated speed. The insulation resistance meter should point to the “0” position when it is short-circuited, and it should point to the “∞” position when it is open.
(5) When using the insulation resistance meter, it should be placed in a stable and firm place, and far away from large external current conductors and external magnetic fields.
