Why is the resistance too large when the loop resistance tester is testing?

1. Reasons for testing equipment

1. The reason for the accuracy of the tester itself is to first ensure that the accuracy of the tester used is completely correct.

2. Check the wiring terminals on the panel of the tester to see if there is any loose contact or oxidation.

3. Ensure that the wiring of the circuit resistance tester is correct, and check whether the voltage input line is connected to the inside of the current output line.

4. The current clamp of the loop resistance tester guarantees reliable contact with the product under test, avoiding excessive contact resistance and affecting the test result.

5. Ensure sufficient test time, and carry out the test according to the time specified by the national standard.

2. The contact resistance of the high-voltage switch itself is too large.

1. Whether both ends of the high voltage switch are grounded. If both ends are grounded, a parallel circuit will be formed. Parallel value. The correct approach is that at least one end of the high-voltage switch is not grounded.

2. The surface of the static and dynamic contacts of the high voltage switch is oxidized.

3. Mechanical impurities or carbides remain between the moving and static contacts of the high-voltage switch.

4. The contact spring is broken, annealed, etc., resulting in a drop in contact pressure)

5. The effective contact area of the loop resistance tester is reduced.