Cranes are often used in industrial production, of which gantry cranes account for the majority, so we should pay more attention to the gantry crane equipment inspection and grounding protection inspection, as long as this can really ensure the integrity and safety of equipment.
For the inspection of gantry crane should not only master the standard inspection method, but also according to the specific inspection content and environmental factors to take targeted inspection method, only in this way can really improve the inspection level.
The inspection of gantry crane includes the inspection of mechanical part and the inspection of electrical part.
Among them, there are various types of inspection methods for the mechanical part, and there are many contents, including the detection of the camber of the girder mid-span and the local buckling of the girder webs.
The test method of arch degree in the middle span of girder of gantry crane is as follows: the girder is padded flat with cushion frame, and the elevation difference between upper cover plates at the two ends of base plates is no more than 2mm.
If it is a double girder structure, the cushion frame should be placed directly below the girder base plate;
If it is a single girder structure, the support center line of the pad frame shall be placed 700mm outside the girder seat plate.
On the one hand, it is necessary to check whether the metal structure of tower crane is well connected with the electrical equipment shell.
On the other hand, check the repeated grounding of zero wire. If the measured repeated grounding resistance is less than or equal to 10, the tower body buried in the ground can be repeatedly grounded; otherwise, an independent grounding body should be set up for repeated grounding.
Not only that, but also check the total current loop of gantry crane tower crane whether there is a short circuit protection device, the selection and setting is in accordance with the provisions, record the rated current of fuse or circuit breaker action setting current;
Calculate or measure phase zero circuit impedance quantitatively to calculate single phase short circuit current.