The loop resistance tester is widely used in the measurement of contact resistance, loop resistance, cable and wire, weld contact resistance of various domestic electrical control switches in enterprises. Our company R & D and production of high-precision loop resistance tester, accurate measurement data, performance comparison. Stable, in line with the requirements of China’s electric power and power supply management department for high voltage switch field maintenance and high voltage switch plant circuit resistance.

So how to maintain the loop resistance tester?

The circuit resistance tester should be placed in a dry, ventilated, dust-free, non-corrosive gas room, shall not be stacked in a wooden box, should be stored with the panel facing up. Place moisture-proof materials at the bottom of the device to protect the device from moisture.

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Several common problems in field testing of loop resistance tester:

1. The voltage wiring circuit is open or has poor contact (the contact resistance is infinite when the wiring is open). When there is strong electromagnetic interference around the test, such as when the bus is charging, the charging bus will use air as the medium and interfere with the two voltage test lines of the tester through the capacitor. Differential mode voltage occurs. First, if the influence of external environmental interference is large, the loop resistance tester will display a value far greater than the resistance value of the tested object. At this time, if the system tester has enough field test experience, it may be possible to judge the abnormal test analysis results to solve the problem in development, but also attract attention, and finally get the correct test research results, but if the tester is inexperienced, it may misjudge the switching circuit resistance value exceeds the standard, and may use power outage maintenance. This method mainly deals with the defects, which will cause some unnecessary losses to the production and life of the power company in the future. Secondly, if the interference intensity is not very large, the display value of the instrument is just within the qualified resistance range of the circuit breaker, and the situation of “poor contact of the voltage circuit” will also lead to misjudgment.

2. In most cases, the circuit breaker terminal will produce an oxide film or oil film on the outer surface of the terminal after long-term operation, which may occur when the voltage test claw of the circuit resistance tester is connected to this type. A patch board. Poor contact, voltage test line claw itself produces a certain contact resistance. When the contact resistance value is equal to the internal resistance value of the voltage sampling circuit, the test result will be seriously affected.

3, open the voltage wiring circuit, open the loop resistance tester, no strong electric field interference in the test site. In this case, since the differential mode voltage of the amplifier input is basically non-existent, the test parameters displayed by the loop resistance tester are close to 0. If the loop resistance tester has sufficient field test experience, the abnormal voltage loop test line can be identified as the loop resistance test line. The electrician suggests to remove the abnormal test line of the instrument voltage loop in order to get the final correct test result. On the contrary, it may misjudge the problem of the tester, interrupt the test, replace or repair the tester, extend the power failure time, and bring unnecessary trouble to the test work.