Cranes are often used in industrial production, with gantry cranes accounting for the majority. Therefore, we should pay more attention to the inspection of gantry crane equipment and its protective grounding. Only in this way can we truly ensure the integrity and safety of the equipment.
For the inspection of gantry cranes, it is not only necessary to master standardized inspection methods, but also to adopt targeted inspection methods based on specific inspection contents and environmental factors. Only in this way can the inspection level be truly improved. The inspection of gantry cranes includes two aspects: mechanical inspection and electrical inspection. There are various types of inspection methods for the mechanical part, and there are also many contents, including the detection of the mid span arch of the main beam and the detection of local warping of the main beam web.
The inspection method for the mid span and upper arch of the main beam of a gantry crane is as follows: use a cushion frame to level the main beam and ensure that the elevation difference between the upper cover plates at both ends of the base plate is ≤ 2mm. If it is a double main beam structure, the cushion frame should be placed directly below the main beam seat plate; If it is a single main beam structure, the centerline of the support frame is placed 700mm outside the main beam seat plate.
In addition, the inspection of protective grounding for gantry cranes requires checking whether the metal structure of the tower crane is well connected to the electrical equipment casing; On the other hand, check for repeated grounding of the zero line. If the measured repeated grounding resistance is ≤ 10, a tower body buried in the ground can be used for repeated grounding. Otherwise, an independent grounding body should be set up for repeated grounding.
Not only that, it is also necessary to check whether there is a short circuit protection device in the total current circuit of the gantry crane tower crane, whether the selection and setting comply with regulations, and record the rated current of the fuse or the setting current of the circuit breaker action; Calculate or quantitatively test the phase zero circuit impedance and calculate the single-phase short-circuit current.