1 because of loose wiring, wiring not tighten, causing poor contact, causing the terminal row fever.

2 motor coil and the outlet terminal not fastened, also can cause fever.

3 terminals of the dust and pollution caused by the creepage distance and short circuit burned out.

4 terminals of the dust and pollution caused by the creepage distance and short circuit burned out.

5 terminal and terminal surface may be caused by oxidation, contact resistance value increases, fever, which caused the fault.

6 caused by damp insulation resistance becomes smaller due to short circuit finally burned

7 creepage distance of the short-circuit phenomenon occurs when less than the corresponding voltage

 

In general, the three-phase terminal motor manufacturers in the factory, the distance between each other is in accordance with the regulations set up manufacturing, the insulation distance should meet the requirements, if the wiring column frame intact, and can not cause short circuit for short arc discharge. Analysis of the fault, to maintain the integrity of the premise in the motor terminal box, there are two issues should be considered, one is in the terminal when burned, the coils of the motor is not burnt, coil all motors are intact, then the problem all out at a terminal, terminal two is sub burnt motor coil injury, is also different.

 

If the motor is shut down for a period of time after put into use, then the possibility of damp, terminal oxidation is relatively large, because of poor contact caused fever caused by burn. If the motor run frequently, in the operation of the terminal burned, should judge is caused by the terminal bolt loose, and there must be a period of time temperature accumulation, coupled with the air humidity increases, the surface oxidation of terminal, also will cause the increase of contact resistance, to a certain extent, this phenomenon is the rate of deterioration more and more quickly, in the junction box is complete, generally difficult to detect, and finally in this fault. So the operation requirements of general electric equipment is also provided, regular inspection and patrol is a good way to reduce the chance of failure, a shutdown, open the box tests can detect early signs of some fault.