The operating power supply of a high-voltage switchgear comprehensive tester is typically rated at 25-265V/10A, with a resolution of 1V and an accuracy of ≤1% reading + 2 digits. In on-site operation and maintenance, power supply settings and sensor matching directly affect test results. The following Q&A is compiled based on common working conditions.
Q: How to correctly select the DC operating power supply before testing?
A: The instrument provides an adjustable DC power supply of 25-265V/10A with a resolution of 1V. It should be set according to the rated operating voltage on the switch nameplate to avoid coil overheating from too high a voltage or mechanism failure to operate from too low a voltage. Before testing, confirm that the power supply output is isolated from the switch secondary circuit to prevent backfeed. An accuracy of ≤1% reading + 2 digits means the deviation between the set value and actual output is small, but it is still recommended to verify key voltage points with an external multimeter.
Q: What are the requirements for displacement sensors for different switch types?
A: The transmission mechanisms of vacuum, SF6, low-oil/high-oil, and GIS combined apparatus differ greatly, and speed measurement sensors are not interchangeable. Linear sensors are suitable for circuit breakers with linear motion, rotary sensors for rotating shafts, universal sensors can adapt to special angles, and laser sensors are suitable for occasions with limited installation space. On site, the corresponding sensor should be selected according to the mechanism structure, and the mounting bracket must be secure to avoid errors introduced by loosening during testing.
Q: How does the ease of sensor installation affect testing efficiency?
A: Easy sensor installation can shorten the working time within the power outage window. When using magnetic or snap-on fixing methods, it is necessary to confirm reliable connection with the moving part under test to avoid distortion of the speed curve due to slipping. For GIS combined apparatus, sensors often need to be installed through observation windows or dedicated interfaces, and the interface dimensions and sensor compatibility should be checked in advance.
Q: How to troubleshoot when test data is abnormal?
A: First check the sensor connection and power supply settings, then confirm whether the switch operating mechanism is normal. If the speed curve shows spikes or flat tops, it may be due to insufficient sensor range or eccentric installation. Excessive ripple in the DC power supply can also interfere with measurement; try adjusting the power supply output or using an external stabilized source. Record the ambient temperature and humidity, and if necessary, take multiple measurements and average them.
