1

When the knife switch on the protective disc is closed, the fuse of the operating circuit is burnt out.

A phase in the control circuit h is grounded

Clear the grounding

2

When the main contactor is closed, the fuse on the lead-in wire is burnt out.

This phase is grounded

Clear the grounding

3

After the controller starts turning, the current relay makes action.

1. The setting values of the overcurrent relay are inconsistent

2. A certain link of the mechanical part is stuck

1. Adjust the relay current to be 225-250% of the rated current of the motor

2. Check the mechanical part

4

The motor cannot reach the rated power, and rotation is slow.

1. The brake is not completely released

2. Voltage drops in the circuit

3. Resistor wiring is wrong

1. Check and adjust the brake mechanism

2. Eliminate the reason why the voltage drop value exceeds the standard

3. Connect the resistor wiring

5

The corresponding motor is not powered off when the terminal switch lever makes action.

1. Short circuit occurs in the circuit of the end switch

2. The order of the wires connected to the controller is disordered

1. Check the conductor leading to the terminal switch

2. Check wiring

6

The contactor does not fall off after the power is turned off.

1. Grounding or short circuit of the operating circuit

2. The contactor contact is welded

3. The contact surface of the armature iron is stuck by the oil stain

1. Find the damaged place with the megohmmeter and then handle it

2. Eliminate the error of the contactor being welded

3. Eliminate the oil stain on the contact surface