Circuit breaker failure

1. The sound of opening is also accompanied by closing

1. The three-phase short circuit of the circuit breaker can not be closed (generally caused by the SCR burnout)

1. Replace the SCR and check the short circuit

2. Measuring circuit breaker has electricity at the upper end and no electricity at the lower end

2. The undervoltage release is burnt out or not sucked in

2. Under the condition that the device is not short-circuited, it can be tied up with a cord to prevent it from popping up

3. There is no reaction and noise when the power is increased

3. The shunt coil has been attracted, check whether the shunt coil is energized when it is closed

3. The end of the coil can be disconnected first, and the mechanical opening is used. After the production is completed, the circuit can be checked again.

4. Thermal relay failure or action

4. The two endpoints of the relay can be disconnected first, and check after production

5. Mechanical failure

5. See if it can be manually closed, and check after production

Line inductance

1. Trip caused by short circuit and ignition of inductance

1. Observe whether the inductance catches fire or the distance between coil turns is close

1. Knock off the coils with a short distance, and insert insulating materials to separate them

2. Burning KP SCR caused by too few turns

2. Check the number of coil turns to see if there are too few

2. Replace the large inductance coil in time

KP SCR in 12- pulse rectification string

1. The two sections of DC voltage are unstable and swing large, and the inverter cannot start

1. Check whether the rectifier voltage equalization resistance is damaged

1. Replace the voltage equalizing resistor, when the swing is still in progress, the two bridge resistors can be connected in parallel

2. View KP SCR

2. Check whether the rectifier reverse diode is damaged

2. Replace the diode

KP SCR

1. The circuit breaker cannot be closed (top circuit breaker)

1. Check whether the KP SCR is burned out

1. Replace the SCR

2. Unable to start

2. Check whether the KP thyristor pulse lights are all on, and the brightness is the same

2. The brightness is not the same, by reason of 3 , . 4 bar checking is

3. The noise is large when the power is increased

3. Check whether the SCR circuit is normal

3. Two lines can be connected temporarily, and the line can be checked after production is completed

4. Check whether the resistance between rectifier thyristors G and K is normal (generally 10-25R ), if it is not normal, check whether it is a line problem or a thyristor problem

4. Proceed to Article 3 for line problems , SCR problems should be replaced

Hollow reactor

1. Because the required inductance of the series reactor is not large, hollow inductors are generally used, which reduces the weight and volume, and reduces the maintenance cost, because the distance between the turns of the coil is long, and the thickness of the copper pipe is not easy to cause fire and water leakage. phenomenon

With iron core reactor

1. Reactor catches fire

1. Measure whether the resistance of the copper ring of the reactor and the iron core are short-circuited (when the incoming line is 380V , the resistance value should be greater than 1K )

1. Disassemble the reactor and check which coil is short-circuited for repair or replacement

2. Unable to start

2. Observe whether there is water leakage in the reactor

2. Disassemble the reactor and check which coil is leaking for repair or replacement

3. Trip when power can be started

3. Reduce the indoor light observation to see if there is a fire

3. If there are no accessories temporarily and the number of reactor turns is large, the broken coil can be removed without affecting the operation of the machine, and it can be temporarily operated until the end of production