How to measure the loop resistance of circuit breaker with high current?

Power Systems Many high-current electrical devices need to accurately measure the resistance of loops in preventive tests and hand-off tests. The circuit breaker is an important electrical equipment in the power system. The national standard GB763, GB50150 and the power industry standard DL/T596 make provisions for the measurement of the circuit breaker's conductive loop resistance: DC voltage drop method should be used to measure and the current should not be less than 100A.

The resistance of the breaker circuit is mainly determined by the contact resistance between the dynamic and static contacts of the circuit breaker. The existence of contact resistance increases the loss of the conductor during power-on, and increases the temperature at the contact. The value of the value directly affects the current-carrying capacity during normal operation, and affects the cutting-off capability of the short-circuit current to some extent. Therefore, the circuit breaker resistance per phase is an important data for circuit breaker installation, maintenance and quality acceptance.

There are many ways to measure the contact resistance. Japanese scholar Isao Minowa proposed using superconducting quantum devices to measure contact resistance. H.Archi proposed using electrolyzer method to measure contact resistance. Polish scholar Jerzy Kaczarek proposed using third harmonic method to measure contact resistance. These methods are generally conducted under laboratory conditions. The method used by the institute. In engineering, the four-terminal method is usually used to measure the contact resistance of actual contacts.

In the past, a DC dual-arm bridge was commonly used to measure the contact resistance of a circuit breaker. However, when using two-arm bridges to measure the circuit breaker's conducting loop resistance, it is difficult to eliminate the oxide film with a large resistance because the two-arm bridge measurement loop passes a weak current, and the measured resistance value is too large. However, the oxide film is easily broken at a large current and does not prevent the normal current from passing through. Therefore, the test should not be too small when using the DC voltage drop test.

The HLY-100A loop resistance tester independently developed by Yangzhou City Fei Ke Te Electric Co., Ltd. adopts the latest power supply technology, high precision, small size, light weight, simple wiring, making the previously very troublesome on-site circuit breaker loop resistance test become more Easy and more convenient.

GOST  12821-80 PN6-PN40

Our flanges are completely finished according to the standard. GOST 12821-80 PN6-PN40 is neck flange with pressure PN6-PN40, and we produce ANSI, JIS, EN, DIN flanges. We grant our buyers with our strict quality control system and good serivce. In addition, we also do the United States, Japan, Britain, Germany, the series of products. won a lot of customer recognition, over the same period the company won three national patents.

Gost 12821-80 Pn6-Pn40

Gost 12821-80 Pn6-Pn40,Gost 12821-80 Pn6-Pn40 Carbon Steel Flange,Gost 12821-80 Pn6-Pn40 Weld Neck Flange

Jinan HeChuang Mechanical Manufacturing Co., Ltd. , http://www.hechuangmechanical.com