In the use of overhead cranes, in order to make it safe and reliable work, eliminate the potential for accidents, maintenance personnel must regularly carry out safety checks on lifting machinery, the inspection includes:
The electromagnetic brake inspection:
- Check whether the mechanical linkage system of the electromagnetic brake system can be flexible action, armature action whether there is a jamming phenomenon, and in the active parts of the lubricant.
- The wiring of the electromagnetic coil must be tight and firm to ensure that the brake armature can be normally absorbed and released. And the coil resistance to ground should not be less than 5M.
- Fasten each fixed bolt, check whether the pressure between the brake tile and the brake wheel is appropriate.
- Check the brake tile material wear, if the wear exceeds 50% should be replaced in a timely manner.
Check the position switch:
- Check whether the position switch installed in each limit part can be accurate and flexible action. And add the right amount of lubricant.
- To prevent metal chips and other debris from dipping into the switch body, the switch should be checked for sealing.
- Check whether the movable and static contacts are intact and whether there are adhesions and short circuits.
- After the inspection, test and check whether the protection function can be realized on the spot.
Check whether the contacts of cam controller and main command controller are in good condition, whether the contact surface of each dynamic and static contact is in a straight line, whether the connecting wires are firm, and whether the ground resistance of each contact should not be less than 0.5M.
Check the resistors used for speed control, whether they are broken or touching each other; the integrity of the insulators, whether the lead wires are solid; measure the insulation of the resistors to the ground, and fill in the asbestos cloth between the resistors with large gaps.
Check whether the sliding contact line is damaged, leakage, insulation is good; brush moving without collision, jumping phenomenon, brush and the wire between the wire has broken strands, if there should be timely replacement and adjustment.
Protect the power distribution cabinet and cab inspection:
- Check the protection switch, emergency stop button, handle, can normal use.
- Check the accuracy of each overcurrent relay action, and readjust if appropriate.
- Check whether the terminals are firm and the fixed bolts are tightened.
- Various indications, displays and ringing signals are normal or not.
- Use megohmmeter to measure the insulation between the cab's box and the electrically charged parts.
In the process of using lifting machinery in addition to the above-mentioned content for regular inspection, should also be the crane motor; protection control panel in the contactor; lifting ropes, etc. for regular inspection.
Overhead crane daily inspection checklist