In their daily work, power workers often need to test the loop resistance of power transformers, so they need to use a loop resistance tester. What kind of equipment is this device? This article will give you a brief introduction to what is loop resistance testing. instrument.

At present, traditional double-arm DC bridges are commonly used in power systems to measure the DC resistance of transformer coils and the contact resistance of high-voltage circuit breakers. The test current of this bridge is only one level. In the conductive ring of the transformer coil, it is difficult to find the defect of reducing the cross-sectional area of the conductor. When measuring the contact resistance of the conductive circuit of a high-voltage switch, due to the influence of the oxide layer between the oil film and the static contact layer, the measured resistance value is several times larger, which hides the true contact resistance value. Therefore, the Ministry of Electric Power Standard SD301-88 "AC 500kv Electrical Equipment Transfer and Preventive Test Regulations" and the new version of the "Electrical Equipment Preventive Test Regulations" stipulate that the measured current of the contact resistance of circuit breakers and disconnectors shall not be less than 100a.. To ensure the accuracy of the measurement.

Combining digital circuit technology and switching power supply technology, a circuit resistance tester is designed. It is suitable for the measurement of contact resistance and circuit resistance of switch control equipment. The test current adopts the DC 100a recommended by the national standard. In the case of a current of 100a, the circuit resistance and contact resistance can be directly measured, and the numerical value can be displayed. The instrument is accurate and stable, suitable for on-site high-voltage switch maintenance and high-voltage switch circuit resistance testing requirements.

The loop resistance tester is a commonly used high-voltage power test equipment. Power workers need to be proficient in its test methods and skills before they can successfully measure the loop resistance of the transformer during work.