The common faults of explosion-proof pneumatic cranes can be classified into four categories: electrical system faults, braking system faults, mechanical component faults, and abnormal operation. The following are specific types of faults and analysis:

1、 Electrical system malfunction

Switch issue:

Reason: The switch itself does not meet the quality standards, or the switch malfunctions due to technical errors or negligence during installation.

Performance: The crane cannot be turned off after work, causing more serious problems such as burnt resistors, abnormal resistance heating, and chaotic closing of controller gears.

Electrical component issues:

Reason: Poor quality of electrical components or overheating caused by prolonged operation.

Performance: There is a chaotic problem with the gear closure of the relevant controller, which cannot return to the zero position normally and can easily cause the contacts to be burned out.

Explosion proof electrical component failure:

Reason: Aging, damage or improper installation of explosion-proof electrical components.

Performance: Decreased explosion-proof performance and potential safety hazards.

2、 Brake system malfunction

Brake coil burnt out:

Reason: The crane has been running continuously for a long time without sufficient heat dissipation, resulting in excessive temperature rise of the brake, insulation material failure, and short circuit between coil turns.

Performance: The brake cannot work properly, affecting the safe operation of the crane.

Rectification module burnt out:

Reason: The overcurrent generated when the brake coil is overloaded and burned out has broken through the diode of the rectifier module, or the quality of the rectifier module itself is not up to standard.

Performance: The brake cannot be powered on normally, resulting in brake failure.

Brake friction plate issue:

Reason: The clearance for adjusting the brake is small, and friction between the friction plate and the brake disc cannot be avoided during the operation of the motor, resulting in an increase in the temperature of the friction plate and the failure of the adhesive due to overheating.

Performance: The adhesive joint of the brake friction plate cracked, accelerating the heating of the motor and brake coil, accompanied by abnormal noise.

3、 Mechanical component failure

Wire rope issue:

Reason: The steel wire rope rotates in the wrong direction, the rope roller frame is skewed, and the pressure of the rope roller on the hoisting steel wire rope is too small.

Performance: The steel wire rope may experience phenomena such as breakage, climbing, misalignment, jumping, and jamming during use.

Wheel malfunction:

Reason: Unreasonable operation method, excessive overload working time leading to bridge deformation, wheel displacement phenomenon, and installation process not meeting actual specifications.

Performance: Wheel gnawing phenomenon occurs, affecting the stable operation of the crane.

Malfunctions of pulleys, drums, gears, and other components:

Reasons: uneven material, installation not meeting requirements, poor contact between rope and wheel, long-term overload operation, etc.

Performance: Uneven wear of the pulley groove, fatigue cracks in the drum, and broken gear teeth affect the normal operation of the crane.

4、 Abnormal operation

Rising stall:

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

Performance: When the master shifts up, the load does not increase, but rapidly decreases.

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.

Performance: When the master returns from downshifting to zero gear, the motor speed does not decrease to zero within the "braking time".

Slipping hook:

Reason: Insufficient braking force of the brake, sudden failure of the brake, etc.

Performance: The lifting mechanism has experienced a loss of control due to hook slipping (including sliding), posing a serious safety hazard.

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