Disconnector contact overheating phenomenon and treatment

Addtime:2023-06-05 13:40:06 Resource:ShenGaosuo Electric Co., Ltd.

When the contact is overheated, the blade and conductor joints change color and darken, the contact part of the color change paint changes color or the temperature indicator sheet changes color, softens, displacement, shines or melts; The outdoor disconnector contact is overheated, and steam or snow can be observed at the joint in rainy and snowy weather; If the contact is severely overheated, the knife edge may burn red and even fusion welding phenomenon may occur.

Overheating of the disconnector operating contacts can be caused by:

(1) The closing is not in place, so that the cross-section of the current is greatly reduced, so that the contact resistance increases, and also produces a great repulsion, reduces the pressure of the spring, relaxes the compression spring or screw, and overheats the contact resistance.

(2) Due to loose contact fasteners, the spring of the blade or knife tip is rusted or overheated, so that the spring pressure is reduced; Or improper force during operation, so that the contact position is not correct. These conditions reduce the contact pressure, increase the contact resistance and overheat.

(3) The knife edge is not tightly closed, so that the surface of the contact is oxidized and dirty; During the pulling process, the contact is burned by the arc, and the wear or deformation of each linkage part will make the contact contact poor, and the contact resistance will increase and overheat.

(4) The disconnector is overloaded, causing the contacts to overheat.

The overheating of bus bar and disconnector contacts is handled as follows:

(1) Measure the temperature of the hot spot with an infrared thermometer to judge the degree of heat.

(2) If the bus bar is overheated, according to the degree and location of overheating, allocate the load, reduce the heating point current, and report the dispatch to assist in the allocation of the load if necessary.

(3) If the disconnector contact is overheated due to poor contact, the contact can be pushed by an insulating rod of the corresponding voltage level to make the contact contact good, but not too strong, so as not to slip and expand the accident.

(4) If the disconnector is overheated due to overload. Schedules should be reported to reduce the load to or below the rated value.

(5) In double busbar wiring, if a busbar disconnector is overheated, the circuit can be reversed to another busbar to operate, and then pull the overheated disconnector. Wait for the bus bar to lose power and then service the overheating disconnector.

(6) In the single busbar wiring, if the busbar disconnector is overheated, it can only reduce the load operation and strengthen monitoring, and temporary ventilation devices can also be installed to strengthen cooling. '

(7) In wiring with bypass busbars, the busbar disconnector or line disconnector is overheated, and it can be poured into bypass operation, so that the overheated disconnector is out of operation or power outage maintenance. Line disconnectors without bypass wiring are overheated and can operate at reduced load, but monitoring should be enhanced.

(8) In 3/2 wiring, if a disconnector is overheated, it can be run in an open loop and pull the overheated disconnector apart.

(9) If the heat of the disconnector continues to deteriorate: when it threatens the safety operation, it should be immediately cut off. The disconnector that cannot be powered off can be processed with live operation.

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