Processing method when the secondary side of current transformer is opened

- Aug 05, 2020-

(1) Find out which group of current loops and open circuits of the fault belong to the current transformer, and whether it affects the relay protection device. Report scheduling, withdraw protection from possible misoperations.

(2) The primary load current should be reduced as much as possible. If the current transformer is seriously damaged, the load should be transferred in time for power failure inspection and treatment (try to change the operation mode as far as possible so that the user does not power off).

(3) The secondary side of the current transformer should be shorted to the nearest test terminal as soon as possible, and then check the open point. When shorting, you should use good short wiring and follow the drawings, wear insulating boots, wear insulating gloves, use insulating tools.

(4) If sparking occurs during short-circuiting, the short-circuiting is valid. In the circuit behind the short-circuit point, you can further find the fault point.

(5) If no spark is generated during short-circuiting, the short-circuiting may be invalid. The fault point may be in the loop in front of the short-circuit point, and the short-circuit point can be changed forward point by point to narrow the inspection range. In order to shorten the time of the secondary side open circuit, first short-circuit the terminal block of the current transformer terminal box.

(6) Within the scope of the fault, it is important to check the terminals and components that are prone to failure, or the parts that have been moved during the operation due to maintenance.

(7) After the fault is checked, if it is a fault that can be dealt with by itself, such as: loose external components such as wiring terminals and poor contact, etc., it can be dealt with immediately and then put into the protection of withdrawal.

(8) If the fault cannot be handled by itself (such as the current transformer and the inside of the relay) or the fault cannot be identified by itself, it should be reported to the superior in time and relevant personnel should be dispatched to deal with it (the secondary side of the current transformer should be shorted first). Or transfer the load by changing the operation mode, check and deal with power failure (to prevent the loss of protection for a long time).