Practical knowledge of electrical engineering

 Three-phase 3 phase induction motor five wire with color yellow, green, red, light blue, respectively the U, V, W, N protective earthing line double color (PE) transformer in operation, each transformer phase current should not exceed electric motor rated current; The maximum unbalance current shall not exceed 25% of the rated rotor current. Transformer operation should be performed periodically maintenance. The same transformer power supply system, unsuitable mixed protective earthing and protection by zero. The voltage transformer secondary coil normally rated voltage 100 v. Secondary side of voltage permanent magnet generator transformer at work may not be rotor and stator short circuit. Due to short circuit will produce a lot acmotor2.blogspot.com of short circuit current, may burn out diesel generator set transformer, voltage transformer for this time, secondary side are installed fuse protection. Secondary side of voltage transformer must be grounded at one end. This is to prevent the secondary synchronous generator coil insulation breakdown, a high pressure into the secondary small diesel engine side, endanger the safety of person and equipment. Current transformer secondary side close to the short circuit conditions at work. Rated current of the secondary coil is commonly 5 a current transformer secondary side is not electric generator allowed to open at work, current transformer secondary side generator must be grounded at one end, to prevent the first and second coil insulation breakdown, the side of a high voltage into the secondary side.