The contact resistance test set under Wuhan UHV can help many power workers conduct various power tests more conveniently.
Correct Procedure:
1. Safety isolation: Completely disconnect the circuit to be tested (such as switches, circuit breakers, busbar connections, etc.) from the power grid or system (open the isolation switch, circuit breaker and exit to the test position, remove the fuse, etc.).
2. Discharge and grounding: Fully discharge the parts that may store charges, such as capacitors and long cables. And reliably ground the equipment near the testing point, release residual charges, and ensure that the equipment potential is zero during testing.
3. Electrical testing: Use qualified electrical testers to conduct electrical testing at testing points to confirm that the equipment has no voltage. This is the most critical safety step!
4. Wiring: After confirming that there is no power, connect the current output lines (C1, C2) and voltage measurement lines (P1, P2) correctly to the designated points of the tested circuit according to the requirements of the tester manual. It is usually required to clamp the voltage wire inside the current wire to eliminate the influence of contact resistance.
5. Testing: Start the tester for measurement.
6. Wiring and restoration: After the test is completed, disconnect the power supply of the tester first, and then remove the test wires in sequence (first remove the voltage wire, then remove the current wire, and finally remove the grounding wire). Finally, restore the device to its original state.