How to improve the electrical interlock of AC contactor of bridge crane
at present, cj12 series forward and reverse AC contactor is widely used in the main hook of bridge crane in China. The originally designed mechanical interlock has little effect because of inconvenient adjustment and easy displacement in operation; Due to structural reasons, the electrical interlock can not effectively prevent the commutation time or the instantaneous power supply short-circuit shooting phenomenon. As we all know, the electrical interlocking of cj12 AC contactor is realized by its own auxiliary contact, but the compression stroke of the auxiliary contact is only 2~3mm, while the overtravel of the moving contact of the main contact is mm, that is to say, when the moving and static contacts of the main contact are not out of contact, the auxiliary contact has lost its interlocking effect, and no matter how to adjust it, it is impossible to solve this defect caused by the structure. To this end, the following improvements have been made
how to repair the pointer of cj12 AC fatigue testing machine in spring test? Remove the gear frame behind the moving iron core of the contactor, cut off the middle section, replace it with a 50mmx80mm steel plate, install a travel switch with the model of lx19-lx1b on the steel plate, and then install it on the contactor, and use the weight of the moving iron core of the contactor to make the travel switch act. As the effective stroke of the travel switch is only 3mm, when the moving iron core of the AC contactor is basically reset, the contactor wire package circuit in the other direction can be connected, so as to ensure that the commutation can be carried out only when the opening distance of the dynamic and static contacts of the main contact is sufficient, and effectively prevent the short circuit between the instantaneous 3 and recycled plastic reinforcement of the contactor during commutation
after refitting, the CJA contactor was tested first, and the effect was very good. It can not play the normal role of the instrument, and the test is carried out on cj12 anya-100a contactor. It is found that due to the light weight of the moving iron core, the pressure on the head of the travel switch is not enough, so it can operate reliably after adjustment. Therefore, it is considered that this modification is ideal for the application of contactors above CJA. Because the contact capacity of this travel switch is 380V, 5A, and it only connects the circuit without cutting off the load, the contact is more durable
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