The key to solve the problem of contact heating of large current contactor is to make the contact closely connected with copper braid and make it not loose. The effective methods are as follows

(1) The contact between the copper braid and the moving contact is enameled with 60% tin and 40% lead. The length of the enameled head is a little shorter than that of the contact and the Glulam frame, which can avoid the fracture caused by the hardening of the long copper braid.

(2) A layer of DGI conductive paste is applied on the contact between the contact and the copper braid. On the premise of ensuring that the pull-in action does not touch the arc extinguishing cover, try to replace the longer screw as far as possible, remove the spring washer, and fix the contact with two cuttlebone caps, so as to prevent the spring washer from losing its elasticity due to thermal annealing and not playing a fastening role.

3.There are two layers of alkali free asbestos white gauze tape at the junction of Glulam frame and copper braid, which will not burn the Glulam frame in case of heating.