The core risk in winter is that insulators contaminated by fog, dust, dirt, or snow will have reduced insulation performance, leading to surface flashover and even high-voltage ground short-circuit accidents, which directly disrupt power supply.
Maintenance Measures:
- Maintain surface cleanliness: Wipe insulators with a towel (cotton yarn ends are strictly prohibited) to remove dust and dirt. Cotton yarn ends may leave fibers, which could cause partial discharge or reduce insulation.
- Enhance insulation performance: After cleaning, apply a layer of insulating silicone oil to the insulator surface. This not only repels dust and moisture but also improves the insulator’s resistance to flashover in humid or snowy conditions.
Outdoor isolating switches face harsh winter environments (wind, frost, rain, snow, fog). Inflexible operating mechanisms or difficulty in operation in cold weather may lead to “failure to cut off power in time,” expanding accidents. Outdoor isolating switches generally require ice-breaking capability and high mechanical strength.
Maintenance Focuses:
- Bearing seat maintenance: Ensure the bearing seat is well-sealed. The grease inside must be clean, free of impurities, and maintain good lubrication to prevent jamming due to cold-induced grease hardening.
- Rotating parts inspection: Check that the rotating shaft and the mechanism in the manual operation box operate flexibly without jamming or obstruction.
- Linkage mechanism adjustment: Ensure the cross-link linkage mechanism is properly adjusted and operates flexibly, avoiding misalignment that could affect switching actions.
Strong winter winds are a major risk factor. Fuses that are poorly assembled, carelessly operated, or not tightly closed may accidentally fall due to slight vibrations from strong winds.
Preventive Measures:
- Assembly adjustment: Properly adjust the distance between the steel sleeves at both ends of the fuse tube to match the size of the fixed part, ensuring a tight fit.
- Post-operation inspection: After operation, test the fit multiple times. Use an insulating rod to touch the operating ring and shake it slightly to check if it is tightly installed. Only confirm it is secure before completing the operation.
The transformer oil conservator is equipped with an oil level gauge to monitor the oil level. In winter, low outdoor temperatures often cause the oil level to drop below the gauge’s lower limit. The oil level is related to the transformer’s operating temperature, load, oil tank leakage, and ambient temperature. Abnormal oil levels affect safe operation.
Oil Level Management and Replenishment Precautions:
- Timely replenishment: When the oil level is abnormal (below the lower limit), replenish oil promptly.
- Pre-replenishment preparation: Before replenishing oil for an operating transformer, switch the heavy gas protection to the signal device to prevent accidental tripping caused by oil level changes or air entry.
- Post-replenishment checks: After replenishment, inspect the Buchholz relay and release accumulated gas in time. If no abnormalities occur within 24 hours, the heavy gas protection can be restored to its normal state.
- Forbidden operation: Do not replenish oil through the oil drain valve at the bottom of the transformer, as this may cause dirt at the tank bottom to enter the transformer body, affecting insulation and cooling.
