Overhead Cranes: Daily Inspection and Maintenance Requirements

 At the start of each shift, your overhead crane should be run through the following tests at a minimum. This is not a comprehensive list, but a minimum reasonable standard of care crane machine. 

Hook Motion Check:

• Since the direction of any three-phase AC motor can be reversed by reversing and lines feeding the motor it is important that the motion travel is in correct relationship with the button being depressed.
• To check/correct hook motion, carefully inch the up button and observe hook motion. If the hook block does not travel up, stop and reverse any two leads for that circuit at the power source.
• Do not attempt to reverse hoist motion by changing control leads in the push button station or at the contactor or change the nameplate of the push button station.

Correct Push Button Directions:

• Make sure all push button labels are correct.

Upper Limit Switch:

• Inch hook carefully up to the hoist keeping an eye on the location of the hook block.
• If the hook stops automatically when the block is close to the bottom of the hoist, the limit is working correctly.
• If the hook block does not stop within the design distance of the hoist body, limit is not working correctly.

Lower Limit Switch:

• Lower hook block while watching wire rope drum.
• Hook block must stop lowering at floor or before last three wraps on drum are unwrapped – whichever is first.
• If either test fails, the limit is not working or set correctly.

Operational Check:

• Move slowly in all travel directions. Ensure no obstructions are present.
• Listen for sounds not typically present in operation of crane in all three motions. 

Overhead Cranes: Daily Inspection and Maintenance Requirements