HTHL-100A 100A automatic transformer circuit breaker contact loop resistance micro ohm meter

100A 200A automatic transformer circuit breaker contact  loop resistance  micro ohm meter

Products features

1. High current: For latest power supply technology, the tester can continuously output high current which overcomes the weakness of instantaneous current produced by pulsed power. It can effectively breakdown/puncture the oxide layer of the switches and then get precise results.
2. Strong anti-interference ability: The last number of test data will stably show in the LCD screen only with ±1 error even in strong Interference situation.
3. Long service life: All the precise resistances used in the tester can reduce the temperature’s impact on the measurement results and military connectors can enhance vibration resistance.
4. Convenience: Small size, light weight.

 Product details

Product parameters 

Brief introduction

Nowadays Power Systems widely use model QJ44 DC double arm bridge to measure contact resistance (DC resistance and Loop resistance of high-voltage circuit breaker) while the minimum current of such model is 1mA which hardly find the decrease of cross-sectional area of transformers’ conductive circuit conductor. The measurement of loop resistance of high voltage switchgear is affected by oil layer and oxide between static and dynamic contact port, so the resistance measurement value will be several times larger, and cannot reflect the true value of contact resistance. Therefore, the Ministry of Electric Power in national standards SD301-88 “AC 500KV Electrical Equipment Transfer and Preventive Test Procedure” and new version of ” Electrical Equipment Preventive Test Procedure” stipulate that the testing current of circuit breaker and isolating switch contact resistance is not less than 100A to ensure accurate test results.

HTHL-100A Micro ohmmeter measures up to the latest power system standards–DL/T845.4-2004 designed for measuring loop resistance of Switching Control Equipment using High-frequency switching power supply technology and digital circuit technology. Test current of the Tester is DC 100A which is recommended in the national standards. The tester can measure the loop resistance at this value and display the result in digital. It is high precision and good stability and can meet most power systems’ requirements in onsite high-voltage switches maintenance and high-voltage switches factory loop resistance measurement. (It performances accurately and stably)