The circuit resistance tester under UHV power can help many power workers conduct various power tests more conveniently.
High voltage circuit breakers increase circuit resistance due to oxidation of contact surfaces and poor contact fastening. When a large current flows, the temperature at the contact point increases, accelerating the oxidation of the contact surface and further increasing the contact resistance. The accident is serious and requires frequent or regular measurement of contact resistance. The "circuit resistance tester" is suitable for testing the contact resistance of the main contacts of high and low voltage switches. The resistance test of various switchgear conductive circuits should not be less than 100A. There are currently three main types of "circuit resistance testers" on the market:
① The output current of the "circuit resistance tester" is 100A, with a range of 1999 μ Ω and a resolution of 1 μ Ω. This "circuit resistance tester" is widely used in the market and is the best-selling.
② The output currents of the circuit resistance tester are 100A and 200A. The measuring range is 1999 μ Ω and the resolution is 1 μ Ω. This type of "circuit resistance tester" is not widely used in the market.
③ The circuit resistance tester outputs four current levels of 100A, 200A, 400A, and 600A, with a range of 1999 μ Ω and a resolution of 0.1 μ Ω. This "circuit resistance tester" is the least commonly used on the market and is suitable for special occasions.
1. According to the four line measurement method, connect the tested product to the dashboard using a dedicated test line. Note that the voltage measurement line should be connected to the inside of the current output line.
2. Turn on the AC220V power supply and press the power switch. At this moment, the ammeter and resistance meter display "000".
3. Press the measurement switch, adjust the current output knob until the ammeter displays "100.0", then read the number on the resistance meter as the resistance value of the tested product and make a record.
4. After the test is completed, turn the current output adjustment knob to the minimum, reset the measurement switch, and then turn off the power switch.
5. If you want to repeat the test, simply reset the measurement switch, re clamp the test clip, and then press the measurement switch.
Circuit resistance tester: According to the requirements of the "Preventive Testing Regulations for Power Equipment" (DL/T 596-1996), the test current for the conductive circuit resistance of various switchgear shall not be less than 100A.
Due to oxidation of the contact surface and poor contact fastening, the contact resistance increases. When a large current flows through, the temperature of the contact point increases,
This accelerates the oxidation of the contact surface, further increasing the contact resistance. If it continues, serious accidents will occur. Therefore, it is necessary to regularly or periodically measure the contact resistance.