Failure status

Failure cause

Troubleshooting method

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 phenomenon.

2

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

The phase is grounded.

Clear the grounding phenomenon.

3

After rotation of the controller, 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 send rated power, and rotation is slow

1. The brake is not completely released

2. Voltage drop in the circuit

3. Wrong wiring of the  resistor

1. Check and adjust the brake mechanism

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

3. Change resistor wiring

5

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

1. In case of short circuit in the circuit of the terminal switch

2. Wrong order of conductor connected with the controller

1. Check the conductor led to the terminal switch

2. Check wiring

6

The contactor does not fall off after the power supply is cut 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 megohm meter for handling

2. Eliminate the failure whether the contactor is welded

3. Eliminate the oil stain on the contact surface