Electrical Fault Detection Method for Bridge Crane
There are currently two main methods for detecting electrical faults in bridge cranes, namely sensory method and emergency method. Both methods utilize senses to perceive the fault point and then determine the type of fault based on surface fault phenomena. The detection efficiency is very low, which can easily lead to the recurrence of faults. This article proposes some fast methods for detecting electrical faults in bridge cranes, hoping to provide you with reference.
This article takes a 5t bridge crane as an example, analyzes the causes of common faults, and proposes a set of intuitive and easy to implement electrical fault detection methods in accordance with the electrical equipment maintenance system specified in GB6067-85.
1. Close the power switch and the fuse of the power fuse will melt
Cause of malfunction: There is grounding or short circuit phenomenon.
Troubleshooting method: Check the power circuit, identify the grounding or short circuit point, and eliminate it.
2. The main contactor does not engage
Cause of malfunction: Emergency switch not closed. The safety position switch of the cabin door is not closed. The controller has not returned to zero position. Contactor coil open circuit or no operating power supply.
Troubleshooting method: Check and close the emergency switch or door position switch. Check the controller to set it to zero position. Replace the contactor coil. If there is no operating power, the power should be restored.
3. After the main contactor is engaged, the overcurrent relay acts and the contactor is released
Fault cause: The controller circuit is grounded.
Troubleshooting method: Disconnect the connection between the protective disk and the controller, and then gradually connect it. Close the contactor once every time it is connected, check the wire according to the operation of the overcurrent relay, and eliminate the grounding fault.
4. After the controller is closed, the overcurrent relay acts and the contactor is released
Fault cause: The setting value of the overcurrent relay is too small, and the stator circuit is grounded.
Troubleshooting method: Readjust the setting value of the overcurrent relay, use a megohmmeter to check and troubleshoot the grounding fault.
The causes of electrical operation faults in bridge crane are very complex. Only by conducting timely detection of these faults, determining the type and cause of the faults, can we identify the prevention and solution strategies for crane electrical faults. Thus reducing the impact on equipment and personal safety, and ensuring the safe operation of electrical equipment.
