Current transformer abnormality and accident handling - News - Global IC Trade Starts Here Free Products

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

GW MB10F 0.8A 1000V rectifier bridge

Photocoupler

Since the current transformer is in normal operation and the secondary circuit is close to the short-circuit state, it is generally considered to be silent, and the current transformer is often accompanied by sound and other phenomena. When the secondary circuit suddenly opens, a high induced potential is generated in the secondary coil, and its peak value can reach several thousand volts or more, which jeopardizes the life and equipment safety of the worker on the secondary circuit, and the high voltage may cause an electric arc to ignite. At the same time, the magnetic flux in the core increases sharply and reaches a high saturation state. The core loss is severely heated and may damage the rheological secondary winding. At this time, the non-sinusoidal wave is caused by the increase in the magnetic flux density, so that the silicon steel sheet vibrates extremely unevenly, and a large noise occurs.

1. When the current transformer is open circuited, if the operation personnel finds such a fault, the load should be kept unchanged, the protection device that may be malfunctioned is deactivated, and the relevant personnel are notified to eliminate it quickly.

Second, the current transformer secondary circuit disconnection (open circuit) processing 1, abnormal phenomena (1) the current meter indication is reduced to zero, the active, reactive meter indication is reduced or has a swing, the meter is slow or stop.
(2) Differential disconnection light card warning.
(3) The current transformer emits abnormal noise or heat, smoke or secondary terminal wire discharge, sparking, etc.
(4) The relay protection device refuses to move or malfunctions (this phenomenon is only found after the circuit breaker has tripped or rejected the trip to cause a step-by-step trip).
2. Exception handling (1) Immediately report the fault phenomenon to the schedule.
(2) According to the phenomenon, it is judged whether the current transformer belonging to the measurement loop or the protection loop is open. Consideration should be given to deactivating protection that may cause malfunction before handling.
(3) Where the secondary circuit of the current transformer is checked, it shall stand on the insulating mat, pay attention to personal safety and use qualified insulating tools.
(4) When the secondary circuit of the current transformer causes an ignition, the power should be cut off first, and then the fire can be extinguished with a dry asbestos cloth or a dry fire extinguisher.

Third, the current transformer body fault current transformer failure in one of the following situations, should immediately stop processing:
(1) The inside emits a strange sound, overheating, accompanied by smoke and burnt smell.
(2) Serious oil leakage, porcelain damage or discharge.
(3) The phenomenon of fuel injection on fire or glue.
(4) The elongation of the metal expander significantly exceeds the specified value at ambient temperature.