Common Faults Of 50 Ton Double Girder Overhead Crane

Common Faults of 50 ton Double Girder Overhead Crane

Double-girder bridge cranes are the most common type of cranes, and 50 ton double-girder bridge cranes often have some simple faults during use, making them unable to work.
 

For new operators or units without maintenance personnel, certain identification techniques must be mastered to avoid affecting the production of the factory while waiting for repairs.

First, the power indicator light of the double-girder bridge crane is on, and the control linkage channel indicator light is on, but the crane cannot start.
 

The maintenance personnel went to the scene to check and found that the safety door from the control room to the platform was not closed. When the mechanic closes the safety door, everything crane works normally.
 

In the safety maintenance of the crane, there are door switches on the car door, driver's cab door and inspection door. When the crane driver or maintenance personnel go to the crane for maintenance, they must open the crane access door or open the crane track beam inspection door.
 

At this time, the closing contact of the electrical switch on the opened door is broken, the main contact of the electrical box is released, the power supply of the crane is cut off, and the crane cannot be started.
 

This protection can not only protect the maintenance personnel from the threat of electrification of the axle pulley, but also prevent others from injuring the maintenance personnel when starting and moving.
 

Therefore, the protection function of the safety door switch is very necessary.

Secondly, the power supply of the double-girder bridge machine is normal, and the safety door is closed, but it cannot be started.
 

The maintenance personnel found that the lifting control cam did not return to the zero position, that is, although the zero position symbol of the cam was at the zero position, it did not touch the zero position repair contact.
 

Most of the reasons for this situation are that the crane has been used for many years, and its contact elasticity is weakened, sometimes forming inaccessible errors. After replacing the new contacts, the deactivation problem can be solved.
 

It can be seen from the structure of the cam manipulator that only when the manipulator handle is in the zero position, the car, the zero contact and the car manipulator will be closed. In any other working position, i.e. non-zero position is in closed position.
 

Therefore, when any manipulator handle is not at the zero position or the zero position contact is not closed, the main circuit of the crane cannot be connected, and the crane cannot start.
 

This can avoid the dangerous accident that the tissue suddenly moves when the handle is reactivated in the operating direction and does not return to the zero position for some reason. This is the zero protection function of the crane.