How to handle an overheated current transformer in an emergency?
Apr 06, 2026| I. Emergency Handling Steps (Execute in order of priority)
1. Immediately reduce the primary load. Quickly transfer part of the load to reduce the current flowing through the transformer, thus reducing heat generation at the source.
2. Activate or install temporary cooling measures. If a backup cooling device is available, put it into operation immediately; otherwise, use forced cooling with a fan or install a temporary water-cooling device for auxiliary cooling.
3. Use an infrared thermal imager to locate the hot spot. Confirm whether the heat source is at the joint, the casing, or internally, and determine whether it is due to poor external contact or an internal fault.
4. Check the secondary circuit status. Confirm that there is no open circuit on the secondary side, as an open circuit will cause deep saturation of the iron core, generating a large amount of heat.
5. Request an emergency power outage. If the temperature continues to rise, exceeding 80℃ for the transformer body or 130℃ for the joint, immediately report to dispatch and request a shutdown for maintenance. ⚠️ Tightening joints or opening covers for inspection while the equipment is energized is strictly prohibited: Operating high-voltage equipment while it is energized poses an extremely high risk and can easily lead to arcing accidents.
II. Inspection and Handling After a Power Outage
1. Inspect primary joints: Check for looseness, oxidation, or burning. Clean and retighten or replace as necessary.
2. Test insulation resistance: Use a 2500V megohmmeter to measure the insulation between the primary and secondary windings and ground to rule out internal moisture or insulation deterioration.
3. Inspect the core and windings: Check for inter-turn short circuits, loose cores, or other faults that could increase eddy currents.
4. Verify equipment selection: Confirm that the rated current of the current transformer meets the actual load requirements to avoid prolonged overload operation.
