The common faults of lever chain hoist can be classified into four categories: mechanical faults, braking faults, electrical faults, and abnormal operation. The following are specific fault phenomena and solutions:

1、 Mechanical malfunction

Roll breakage

Reason: Long term friction between the drum and the steel wire rope leads to thinning of the drum wall. When the thinning reaches a certain degree or cracks appear, the drum may break due to the inability to withstand the weight of the steel wire rope.

Solution: Regularly check the thickness of the drum wall. If the thinning reaches 18% or cracks appear, it should be repaired and replaced in a timely manner. At the same time, pay attention to lubricating the drum and wire rope to reduce friction.

Wire rope breakage

Reason: The stress on the steel wire rope is complex, and the distribution of stress on the steel wires at different positions is uneven; When passing around the drum and pulley, stress is generated, and pressure is generated between the steel wires; Carrying heavy objects beyond the carrying capacity; Excessive winding of pulleys and drums can cause damage or breakage of the steel wire rope.

Solution: Avoid overloading, regularly check the wear of the steel wire rope, and replace damaged or broken steel wire ropes in a timely manner. At the same time, pay attention to the maintenance of pulleys and drums to reduce the number of winding times.

Pulley malfunction

Reason: Uneven wear of pulley groove, wear of pulley core shaft, inability of pulley to rotate, inclination and looseness of pulley, cracks or broken wheel rim of pulley, etc.

Solution: Regularly check the wear of pulleys and replace severely worn pulleys in a timely manner. For problems such as wear on the pulley core shaft and inability to rotate the pulley, maintenance or replacement should be carried out.

2、 Brake malfunction

Brake failure (heavy object sliding down)

Reason: The lever hinge is stuck, the brake wheel or friction plate is contaminated with oil, the electromagnetic iron core has insufficient travel, the brake wheel or friction plate is severely worn, the main spring is loose or damaged, the lock nut or pull rod is loose, and the hydraulic thruster impeller does not rotate properly.

Solution: Remove the stuck part and lubricate the hinge; Clean the brake wheels and friction pads to remove oil stains; Adjust the stroke of the electromagnet or main spring; Replace worn brake wheels or friction pads; Tighten the locking nut and check the pull rod; Repair hydraulic thrusters or electrical components.

The brake does not release

Reason: Hydraulic cylinder or solenoid coil burned out, wire to solenoid disconnected, friction plate stuck to brake wheel, movable hinge stuck, main spring force too high or counterweight exceeding standard, brake rod bent, improper use of oil, voltage below 85% of rated value, etc.

Solution: Replace the burnt hydraulic cylinder or electromagnetic coil; Reconnect the wires to ensure the circuit is unobstructed; Clean the friction plate with kerosene to eliminate adhesion; Lubricate the movable hinge to eliminate jamming; Adjust the main spring force or reduce the counterweight; Straighten or replace the top rod; Replace the appropriate oil according to the ambient temperature; Check the power supply voltage to ensure stable power supply.

3、 Electrical malfunction

Motor failure

Reason: Sudden insufficient motor torque (such as low power supply voltage, open circuit in one or two phases of the rotor circuit, missing phase in the stator circuit, open circuit in the motor winding, etc.), motor overheating (such as increased power supply rate, working at low voltage, improper motor selection, etc.).

Solution: Check the power supply voltage to ensure stable power supply; Check the motor winding and rotor circuit, repair open circuits or open circuit parts; Adjust the motor load to avoid overload use; Choose the appropriate electric motor to ensure that the performance parameters match.

Contactor failure

Reasons: coil heating (such as coil overload, inability of magnetic current path to contact fixed parts, etc.), increased buzzing sound of the contactor (such as coil overload, dirt on the surface of magnetic current path, etc.), contact heating or burning (such as insufficient contact pressure, contact dirt, etc.).

Solution: Reduce the pressure of movable contacts on fixed contacts, eliminate deflection, jamming, and dirt; Adjust the contact pressure, clean or replace the contact; Check the fuse of the control circuit to ensure that the circuit is unobstructed.

4、 Abnormal operation

Rising stall

Reason: The sudden insufficient torque of the motor may be due to low power supply voltage, open circuit in one or two phases of the rotor circuit, or missing phase in the stator circuit.

Solution: Check the power supply voltage and motor winding to ensure stable power supply and smooth circuit.

Downward brake timeout

Reason: Sudden insufficient motor torque, load weight significantly exceeding the rated load weight of the motor, open circuit of one or two phases of the motor rotor, improper setting of braking time, etc.

Solution: Adjust the motor load to avoid overloading during use; Check the motor winding and rotor circuit, repair open circuits or open circuit parts; Adjust the braking time setting to ensure effective braking.

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