According to GB/T 1984—2014 "High-voltage Alternating-current Circuit-breakers" and DL/T 596—2021 "Preventive Test Code for Electric Power Equipment", the mechanical characteristics test of circuit breakers requires measurement of opening and closing times, simultaneity, travel curves, and coil current waveforms. The KC-8500 Switch Characteristics Tester is designed for acceptance and routine tests of 10kV–220kV circuit breakers. It adopts a dual ARM + FPGA architecture, with a time measurement resolution of 0.1ms, travel measurement accuracy of ±1% ±1 digit, and coil current measurement range of 0–20A, meeting the on-site requirements for clear capture of opening and closing coil current waveforms and accurate measurement of time parameters.
Conventional solutions mostly use a single ARM processor or general-purpose data acquisition cards, which are prone to sampling rate reduction and inter-channel synchronization deviation when simultaneously acquiring multiple time channels and analog channels, resulting in relatively large calculation errors in opening and closing asynchronism time. The KC-8500 implements multi-channel parallel sampling and hardware synchronous triggering through FPGA, with a synchronization error of less than 0.1ms between time channels and analog channels, and a coil current waveform sampling rate of no less than 20kHz, which can clearly restore the details of the rising edge and hold section of the opening and closing coil current. In addition, the instrument supports automatic identification of travel sensors. After connecting a linear or rotary sensor, it automatically matches the range and calibration parameters, reducing manual setting steps when testing different types of circuit breakers. It has a built-in template library of national and industry standards, and automatically compares and interprets after the test is completed, reducing dependence on operator experience.
The instrument housing must be reliably grounded to prevent induced voltage from damaging the equipment or endangering personal safety. Before testing, confirm that the circuit breaker is in the open position and disconnect the operating power supply. When wiring, connect the opening and closing coils, travel sensor, and auxiliary contacts according to the color markings to avoid strong current entering the signal circuit. During the test, the instrument displays the travel-time curve and coil current waveform in real time, and supports waveform zooming and cursor reading. After the test, turn off the operating power supply first, and then remove the wiring. The instrument is suitable for routine detection of circuit breaker mechanical characteristics in substations, switchgear production workshops, and maintenance teams.
