Common fault analysis and improvement suggestions for explosion-proof electric hoists

1、 Unable to start or operate

Fault analysis:

Power issue:

The power fuse is blown or disconnected, causing the motor to start single-phase with zero starting torque and unable to rotate.

The voltage of the power grid is too low, and the starting torque is proportional to the square of the voltage. The acceleration torque cannot overcome the load torque and cannot reach the operating speed.

Load or transmission issues:

The load is too large, exceeding the rated bearing capacity of the explosion-proof electric hoist.

Mechanical transmission failures, such as damage or blockage of components such as gearboxes and couplings.

Improvement suggestions:

Check the power supply:

Use a test pen or multimeter to check if the power fuse is intact. If it is broken, replace the fuse.

Measure the input voltage of the motor to ensure that the voltage is within the rated range. If the voltage is too low, it is necessary to increase the grid voltage or adjust the power supply line.

Adjust load and transmission:

Reduce the load and ensure that it is used within the rated load-bearing capacity of the explosion-proof electric hoist.

Check the transmission mechanical components, such as gearboxes, couplings, etc., and replace damaged or stuck parts in a timely manner.

2、 Abnormal noise occurs during operation

Fault analysis:

Control circuit malfunction:

Poor contact of contactor contacts, inconsistent voltage levels, and stuck magnetic cores can cause the control circuit to emit "hum" noise.

Motor or reducer malfunction:

The motor produces abnormal noise due to single-phase operation, bearing damage, misaligned coupling axis, or "sweeping the bore".

The lack of lubricating oil, worn or damaged gears, and damaged bearings in the reducer can cause abnormal noise.

Improvement suggestions:

Maintenance control circuit:

Repair the faulty contactor, and if the contact is poor, polish or replace it; If the voltage level does not match or the magnetic core is stuck, replace the contactor.

Maintain the motor and reducer:

Stop the machine and check the motor. If it is running single-phase, check the number of phases in the power supply; If the bearing is damaged, replace the bearing; Adjust the coupling if the axis of the coupling is not regular; If the motor is "sweeping the chamber", it should be overhauled or replaced.

Regularly add or replace lubricating oil to the reducer to ensure that the gears and bearings are fully lubricated; If the gears or bearings are damaged, replace them in a timely manner.

3、 When braking, the sliding distance of the stop exceeds the specified requirements

Fault analysis:

Brake ring wear:

Excessive wear of the brake ring reduces the pressure of the brake spring and decreases the braking force.

Brake surface contamination or poor contact:

There is oil stains on the brake surface, which reduces the friction coefficient and causes slipping during braking.

The brake ring has poor contact with the conical surface of the rear end cover, resulting in insufficient contact surface and insufficient braking force during braking.

Improvement suggestions:

Adjust or replace the brake ring:

Adjust the brake nut according to the instructions and increase the pressure of the brake spring.

If the brake ring is worn out too much, replace the brake ring.

Clean the brake surface and adjust the contact:

Remove the brake ring, thoroughly clean the brake surface, and restore the friction coefficient of the brake surface.

Check the contact between the brake ring and the conical surface of the rear end cover. If there is poor contact, repair or replace the parts.

4、 The temperature rise of the electric motor is too high

Fault analysis:

Overloading usage:

The load is too large, exceeding the rated carrying capacity of the motor, causing the motor to heat up.

Motor bearing or brake failure:

The motor bearings are damaged, resulting in frictional heating.

The brake clearance is too small and not completely disengaged, generating a large amount of friction. Friction heating also increases the additional load.

Improvement suggestions:

Control load:

Ensure that the motor is used within its rated load capacity to avoid overloading.

Maintain motor bearings and brakes:

Check the motor bearings and replace them promptly if damaged.

Adjust the brake clearance again to ensure that the brake is completely disengaged.

5、 Other common faults and improvement suggestions

Fault analysis:

Poor contact between collector and sliding contact wire:

The interface of the sliding contact line is uneven, the collector spring is corroded and ineffective, or there is a chamfer in the position of the carbon brush contact, resulting in poor contact or phase loss.

Loose connecting bolts:

Poor assembly quality or low quality of spring washers in the manufacturing plant can lead to loose connecting bolts.

Improvement suggestions:

Improve the contact between the current collector and the sliding contact wire:

Strengthen the position of the sliding line interface to ensure a smooth interface.

Replace the corroded spring of the current collector and polish the carbon brush contacts to make them smoother.

Strengthen assembly quality and regular inspections:

The manufacturing plant should strictly control the assembly quality to ensure that the connecting bolts are tightened.

Users should regularly check the operation of each link of the explosion-proof electric hoist, and promptly repair any abnormalities found.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment