The power frequency withstand voltage test device is the core equipment for insulation performance testing of power equipment, and its maintenance and operation directly affect the accuracy of test results and the service life of the equipment. The following is an explanation from four aspects: daily maintenance, operation standards, fault handling, and safety precautions.
1. Key points of daily maintenance
① Appearance and connection inspection
Regular inspection: Check monthly whether the equipment casing is damaged, whether the grounding wire is secure, and whether the insulation layer of the high-voltage lead is aged or cracked.
Fastener inspection: Ensure that the wiring terminals, bolts, and other fasteners are not loose, to avoid poor contact that may cause heating or ignition.
② Electrical performance testing
Insulation resistance test: Every six months, use a megohmmeter to measure the insulation resistance of the high-voltage output terminal to ground, which should be ≥ 100M Ω (refer to GB/T 16927.1).
Leakage current monitoring: Regularly test the no-load leakage current. If it exceeds 10% of the rated value, insulation problems need to be investigated.
③ Mechanical component maintenance
Regulator maintenance: Clean the carbon brush and slip ring of the regulator every quarter, apply specialized conductive paste, and ensure good contact.
Oil immersed transformer: Check whether the oil level is normal, whether the oil color is clear, and if necessary, filter or change the oil.
④ Storage and transportation
Storage environment: The equipment should be stored indoors in a dry, ventilated, and non corrosive gas environment, with a temperature of -10 ℃~+40 ℃ and a humidity of ≤ 80%.
Transportation protection: During transportation, it should be securely fixed to avoid severe vibrations, and high-voltage components should be wrapped in shock-absorbing materials.
2. Operating standards
① Preparation before the experiment
Environmental inspection: Ensure that the test site is free of flammable and explosive materials, with a humidity of ≤ 80% and a temperature of ≥ 5 ℃ (to prevent insulation materials from getting damp or becoming brittle at low temperatures).
Equipment grounding: The shell of the test device, the shell of the tested object, and the shielding layer of the high-voltage lead must be reliably grounded with a grounding resistance of ≤ 4 Ω.
Subject handling: Clean the surface of the subject, remove all external connections (such as secondary circuits, grounding switches), and avoid interference.
② Experimental process control
Boosting speed: Control the boosting speed according to standard requirements (such as 1-3kV/s) to avoid insulation breakdown caused by sudden voltage changes.
Voltage holding: After reaching the test voltage, hold for a specified time (such as 1 minute) and observe the fluctuation of the ammeter.
Exception handling: If there is discharge sound, smoke, or a sharp increase in current, immediately reduce voltage, cut off power, and discharge.
③ Post experimental processing
Full discharge: Use a discharge rod to discharge the high-voltage end of the test sample and test device for at least 5 minutes (capacitive equipment needs to be extended).
Data recording: Record the test voltage, current, time, and abnormal phenomena as the basis for equipment status evaluation.
3. Common faults and their solutions
| Fault phenomenon | Possible reasons | processing method |
| Unable to boost voltage | Poor contact of carbon brush in regulator | Clean the carbon brush and adjust the slip ring pressure |
Output voltage fluctuation | Unstable power supply voltage or regulator malfunction | Check the quality of the power supply and repair the voltage regulator |
| Overcurrent protection action | The insulation of the test sample is damaged or the circuit is short circuited | Check the test sample and identify the short circuit point |
| Partial discharge abnormality | There are air gaps or impurities inside the insulation | Clean the test sample and return it to the factory for repair if necessary |
4. Safety precautions
① Personnel protection
Operators must wear insulated gloves and shoes, and stand on insulated pads to operate.
Warning signs should be set up in the experimental area to prohibit unrelated personnel from entering.
② High voltage operation specifications
Before boosting, ensure that all personnel stay away from the high-voltage area and maintain a safe distance (e.g. 10kV equipment ≥ 0.7 meters).
It is strictly prohibited to touch high-voltage components or change wiring during the testing process.
③ Emergency situation handling
If breakdown or flashover occurs, immediately cut off the power and discharge, wait for 15 minutes before approaching the equipment.
Record the fault phenomenon, analyze the cause, and repair it before retesting.
④ Long term suspension management
Long term unused equipment should be powered on once a month to prevent components from getting damp and aging.
Cover with a dust cover during storage to prevent metal parts from rusting.
Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website: www.kvtester.com
