The switch mechanical characteristic tester is a high-precision specialized instrument used for testing the mechanical dynamic characteristics of high-voltage circuit breakers. It is of great significance in the power system. The performance of the circuit breaker directly affects the safe operation of the entire power grid, and the mechanical characteristic parameters are the core basis for judging its performance.
Main functions
The instrument can comprehensively test the mechanical characteristics of the circuit breaker. The core test items are as follows:
Time parameters: Measure the inherent opening/closing time of 12 contacts, the same-phase synchronization, the phase-to-phase synchronization, and the reclosing time (such as opening – closing – opening).
Speed and travel: Measure the initial opening/closing speed, the maximum speed, the average speed, as well as the total travel, opening distance, overtravel, and overshoot travel, and draw the travel-time characteristic curve.
Circuit coil current and action voltage: Record the current waveform of the opening/closing coil, and automatically complete the low-voltage operation test of the circuit breaker. Working principle
The instrument is centered around a high-performance microprocessor (such as a single-chip microcontroller or DSP), combined with high-precision sensors and signal processing circuits to achieve testing functions.
Signal acquisition: Through displacement sensors (linear or rotary sensors) connected to the moving contacts of the circuit breaker, and the break-off lines connected to both ends of the break-off, mechanical motion signals and electrical on-off signals during the switch action process are collected in real time.
Core algorithm: After issuing a closing / opening command (using an internal adjustable DC power supply of the instrument), the microprocessor starts high-speed sampling. Taking the moment of coil energization as the starting point, by analyzing the change in break-off status and sensor displacement data, various parameters such as time, speed, and stroke are accurately calculated.
Standard operation procedure
To ensure test accuracy and personal safety, it is recommended to operate according to the following procedure:
Safety preparation
Power off and test voltage check: Confirm that the circuit breaker under test has been isolated from the high-voltage line, powered off, and completed the test voltage check, and hang the “Do Not Close” sign.
Grounding: Securely ground the main unit of the instrument.
Connection and installation
Break-off line: Connect the break-off signal lines of the instrument to the normally open auxiliary contacts of the circuit breaker phase by phase.
Sensor: Select and install displacement sensors according to the type of switch. Linear sensors are commonly used for vacuum switches, and rotary sensors are mostly used for SF6 switches.
Opening and closing control lines: Connect the instrument’s opening and closing control lines and common control lines to the secondary control circuit of the circuit breaker; if using the internal power supply of the instrument, the original operating power supply of the switch cabinet should be disconnected.
Parameter setting and testing
Settings: Configure the test type (conventional test, reclosing test), switch type (vacuum / SF6 / oil), sensor type, and stroke, etc. in the instrument.
Execution: After confirming that the parameters are correct, select the opening test or closing test, and the instrument automatically outputs current to drive the switch action and collects data. Data analysis
View Results: After the test is completed, view the time, speed, travel data and waveform graph on the screen.
Waveform Analysis: By comparing the travel-time curve with the coil current waveform, determine if there are any potential faults such as contact jamming, mechanism sticking, or spring fatigue.
Generate Report: Save the test data and export it via USB or print the test report by connecting a printer.
Key Performance Indicators Reference
Time Measurement: Measurement range 0 – 16000.0 ms, resolution 0.1 ms, accuracy ±0.1 ms
Speed Measurement: Measurement range 0 – 20.00 m/s, resolution 0.01 m/s, accuracy ±(1% reading ±0.1) m/s
Travel Measurement: Measurement range 0 – 900 mm, resolution 0.1 mm, accuracy ±(1% reading ±0.1) mm
Coil Current: Measurement range 0 – 20 A, resolution 0.01 A
Operating Power Supply: DC 30 – 250 V, instantaneous working current 20 A, supports digital adjustment
Post time: Mar-24-2026