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Top 8 Electric Chain Hoist Failures and Effective Repair Solutions
September 07, 2024
Table of Contents
Electric chain hoists are essential tools in many industries, offering reliable lifting and material handling capabilities. However, like all mechanical equipment, they can encounter issues that disrupt their functionality. In this comprehensive guide, we will delve into the 8 most common electric chain hoist repair problems and provide you with practical solutions to address them. Whether you’re experiencing unresponsive controls, overheating motors, or directional movement errors, this guide will help you troubleshoot and repair your electric chain hoist efficiently.
Electric Chain Hoist Failure 1: Hoist Operation Unresponsive
Cause
Repair
No power
Check the three-phase power breaker, switch, fuse, and connecting cables.
Incorrect power voltage and frequency
Check if the on-site power voltage and frequency match the specifications on the hoist nameplate.
Overload
Reduce the load to within the hoist’s rated capacity.
Incorrect, loose, or damaged internal wiring
Inspect the wiring according to the wiring diagram and replace any damaged cables.
Hoist motor overload or thermal protection switch activated
Refer to the section on “Motor or Brake Overheating” in this table.
Brake not releasing
Check the brake coil and replace the brake if necessary.
Check the rectifier input/output voltage and replace the rectifier if necessary.
Contactor malfunction
Inspect the hoist control contactor and its connecting cables. Replace the contactor if necessary.
Emergency stop switch triggered or pendant control button damaged
Unlock the emergency stop switch by turning it clockwise. Check all pendant control buttons and contacts and replace any faulty components if necessary.
Transformer malfunction
Check the transformer for signs of overheating or burn damage and inspect the coil windings. Replace the faulty component if necessary.
Motor burnout
Replace the motor rotor, stator, or other damaged components.
Electric Chain Hoist Failure 2:Hoist Moving in the Wrong Direction
Cause
Repair
Incorrect power phase sequence
Check the power phase sequence and swap two of the three-phase power lines.
Incorrect electrical wiring
Check all wiring according to the electrical wiring diagram.
Electric Chain Hoist Failure 3: Motor or Brake Overheating
Cause
Repair
Incorrect voltage or frequency
Check if the on-site power voltage and frequency match the specifications on the hoist nameplate.
External environment temperature too high
If the ambient temperature exceeds 40℃, reduce the hoist’s operating frequency. Take measures to lower the ambient temperature, such as improving ventilation or moving the hoist away from heat sources.
Electric Chain Hoist Failure 4: Hoist Can Lift But Cannot Lower
Cause
Repair
Electrical circuit for lowering is open
Check the reliability of the lowering control circuit wiring and inspect the electronic limit switch on the lowering side.
Pendant control wire contact is poor
Check the reliability of the pendant control wire core. If the wire core is broken, replace the entire pendant control wire.
AC contactor malfunction
Check the contactor coil and wiring. Replace the contactor if necessary.
Pendant control button or contact malfunction
Check if the pendant control button is stuck and if the contacts are faulty. Replace them as needed.
Chain jamming
Check if the chain can smoothly enter the chain box, and inspect the chain links for any foreign objects. If any damage is found on the chain or the chain guide, replace them promptly.
Electric Chain Hoist Failure 5: Hoist Can Lower but Cannot Lift
Cause
Repair
Hoist overload
Reduce the load to within the hoist’s rated capacity.
Low power voltage
Check if the on-site power voltage and frequency match the specifications on the hoist nameplate. Measure the voltage at the hoist input power terminal block.
Electrical circuit for lifting is open
Check the reliability of the lifting control circuit wiring and inspect the electronic limit switch on the lifting side.
Pendant control wire contact is poor
Check the reliability of the pendant control wire core. If the wire core is broken, replace the entire pendant control wire.
AC contactor malfunction
Check the contactor coil and wiring. Replace the contactor if necessary.
Friction clutch malfunction
Inspect the clutch settings or replace it.
Chain jamming
Check if the chain can smoothly enter the chain box, and inspect the chain links for any foreign objects. If any damage is found on the chain or the chain guide, replace them promptly.
Electric Chain Hoist Failure 6: Unable to Lift Rated Load or Achieve Normal Lifting Speed
Cause
Repair
Hoist overload
Reduce the load to within the hoist’s rated capacity.
Low power voltage
Check if the on-site power voltage and frequency match the specifications on the hoist nameplate. Measure the voltage at the hoist input power terminal block.
Friction clutch malfunction
Inspect the clutch settings or replace it.
Chain jamming
Check if the chain can smoothly enter the chain box, and inspect the chain links for any foreign objects. If any damage is found on the chain or the chain guide, replace them promptly.
Electric Chain Hoist Failure 7: Hoist Drifts after Stopping
Cause
Repair
Brake not engaging
Check the brake status and its “gap” value. Replace it as needed.
Hoist overload
Reduce the load to within the hoist’s rated capacity.
Exceeding duty cycle
Lower the hoist duty cycle.
Electric Chain Hoist Failure 8: Periodic Control Failure of the Hoist
Cause
Repair
Contactor contact is poor
Check if the contactor contacts are burnt and replace them if necessary.
Poor cable contact
Inspect all cables and terminal blocks and replace them as needed.
Pendant control button or contact poor contact
Check if the pendant control button is stuck and if the contacts are faulty. Replace them as needed.
Note:
Inspections and repairs must be carried out by trained professionals.
Be aware that the electrical components of the hoist involve high-voltage connections; take precautions to prevent electric shock, which can result in serious injury or death.
Always disconnect the power supply before performing inspections and repairs.
Clearly mark the area with “Under Inspection” signs.
Do not perform inspections or repairs while the hoist is under load.
By understanding and addressing these common electric chain hoist repair issues, you can extend the lifespan of your equipment and ensure smooth, efficient operations. Regular maintenance and timely repairs not only prevent costly downtime but also enhance safety in your workplace. As a leading manufacturer of cranes and electric hoists, Dafang Crane is committed to providing top-quality products designed for durability and performance. Explore our range of advanced lifting solutions on our website, and discover how our innovative hoists and cranes can meet your material handling needs with unmatched reliability.
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