Cranes are often used in industrial production, of which gantry cranes account for the majority. Therefore, we should pay more attention to the inspection of gantry crane equipment and its protective grounding inspection, as long as this can truly 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 the gantry crane includes the inspection of the mechanical part and the inspection of the electrical part.Among them, there are various types of inspection methods for the mechanical part, including the detection of the camber of the girder midspan and the local buckling of the girder web.
The test method for the camber of the main girder of the portal crane is as follows: the main girder shall be leveled with a pad frame, and the elevation difference between the upper cover plates at the seat plates at both ends shall be no more than 2mm.If it is a double girder structure, the support frame should be placed directly under the girder plate;If it is a single girder structure, the center line of the pad support 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 the zero line. If the measured repeated grounding resistance is less than or equal to 10, the embedded tower body can be used for repeated grounding; otherwise, an independent grounding body should be set for repeated grounding.
Not only that, but also check the total current loop of gantry crane tower has short circuit protection device, selection and setting is in accordance with the provisions, record the rated current of the fuse or circuit breaker action setting current;Calculate or test phase zero circuit impedance quantitatively to calculate single phase short circuit current.