A, the principle of electrical maintenance
1, for defective electrical equipment, no emergency to begin, should be asked to produce failure after and before and after the failure phenomenon. For new equipment, but also should be familiar with the circuit principle and structure characteristics, comply with the relevant rules. Removal should be thoroughly familiar with all electrical components before the function, location, connection mode and its relationship with other devices around, in the absence of the assembly diagram, should disassemble, sketching, and on the tag.

2, should check whether there is any obvious cracks and defects on equipment, understanding of the history of its maintenance, use fixed number of year, etc., and then to check inside the machine. Before dismantling should line up around the fault factors, identified as machines to remove after failure, otherwise, remove blindly, will likely be the repair the bad ? equipment