Look at (1) smoking.

The smoke from the electrical equipment runs in white, yellow and black. White smoke is the steam generated by the heating of the damp electrical equipment, but it is not smoke. Once it is dry and dehumidified, there is usually no problem.
If electrical equipment is yellow smoke in operation, and can be concluded that the overheating of the electrical equipment, because of mechanical failure or power problems make over current electric equipment, large current will be bamboo, wood, such as tape, insulation paper, paint baking to 150 degrees Celsius, the insulation material fast carbonization on the electrical equipment, will be emitted rust-worn gears flaking.
If black smoke is taken, the potential for damage to electrical equipment is high, which means the insulation of electrical equipment is burnt out.
(2) the arc
Electrical equipment is short circuit to produce arc, if arc is red, the explanation is to burn copper, show that copper equipment has been damaged.
Arc is the dazzling white, is the steel piece electric arc; In the arc, the wisps of white silk are rolled out. The zinc in the galvanized is vaporized in the arc.
Various metals undergo different temperatures and their colors become different. Copper is black with temperatures above 100 degrees Celsius in the air; The iron heats up to 300 degrees centigrade and turns purple and blue, heats up to above 600 degrees Celsius and becomes red at 1, 000 degrees Celsius, while aluminum will crack at 658 degrees Celsius.
(3) the coil
If the coil has a color mutation, consider whether there are moisture or corrosive substances around it. If the insulation material of the cable or wire connector is discolored or cracked or peeled off, it must be caused by a poor conductor contact that causes fever.
(4) the temperature
During summer peaks, to the comprehensive and accurate grasp the distribution network equipment operation level, the request power supply sorghum hand-held infrared thermometer, for different levels of load test line, keep the high temperature, high load time data collection and analysis.
Temperature measurement process, the staff is on line all contact drainage line, transformer, switch and cable first main heating area to carry out the PuCe, and the important user and power acquisition system monitoring to heavy differentiation, overload equipment patrol, timely found the defects such as local heating equipment and facilities.
2, smell
Use the human sense of smell, according to the smell of electrical equipment can also judge the failure. If overheat, short circuit, breakdown, it is possible to smell burning smell, fire smoke and plastics, rubber, paint, lubricating oil and other heat volatiles.
3, ask
When the power equipment failure, the maintenance personnel and doctors, the first need to understand the detailed "illness". The whole process of understanding the equipment usage, the medical record and the failure of the equipment to the equipment operator or user. If the fault occurs during or after the operation, it should also be asked about the contents of the operation and the methods and procedures. Generally speaking, it is necessary to know the details and the truth as much as possible, which is often the key to quickly find out the cause and location of the fault.
4, cut
Contact electrical equipment with hands can also "cut" out of trouble.
When the palm of the hand stopped on the electrical equipment for a long time, it felt very hot, the surface temperature of the electrical equipment reached about 50 degrees Celsius. The internal temperature of the electrical equipment is 10 ~ 20 degrees above the surface temperature. Once the electrical equipment is overheated, it will accelerate the insulation aging and shorten its life.
When the insulation paper is broken at 90 degrees on the electrical equipment, it indicates that the electrical equipment has been subjected to high temperature and the insulation may have aged. When the cable or conductor's insulated core is folded into 90 degrees, after repeated two or three times, the line is brittle and cracked, indicating that the cable or wire has been subjected to high temperature for a long time, and the insulation strength has become very low.