tailieunhanh - OPERATION, MAINTENANCE AND REPAIR OF AUXILIARY GENERATORS Episode 10

Tham khảo tài liệu 'operation, maintenance and repair of auxiliary generators episode 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | TM 5-685 NAVFAC MO-912 6-5. Paralleled with the electric utility system. a. Stations that can be paralleled with electric utility systems have the same basic characteristics as those discussed in paragraph 6-2. They have additional features including synchronizing circuitry and in the case of the unattended station an automatic mode. b. The prime movers in these stations can be operated in the manual or automatic mode. Operation in the manual mode is discussed in paragraph 6-2a. In the automatic mode relays in the switchgear will sense the loss of commercial power and provide a starting signal to the prime mover. It will then accelerate under control of the governor to the operating speed. The remainder of the prime mover operation is as previously discussed. c. This discussion is the same as paragraph 6-4 d with the exception that if the station is in automatic excitation will be applied by the automatic circuitry. Also in automatic the main circuit breaker will close automatically provided the incoming line circuit breaker is open. d. The comments regarding proper switchgear operation as noted in paragraph 6-4h pertain to paralleling with the utility system. In addition this type of system requires paralleling circuitry which is part of the switchgear. It includes one or more synchronizing switches a synchroscope synchronizing lights incoming voltmeter incoming frequency meter running voltmeter and a running frequency meter. The synchronizing circuitry is energized by turning the synchronizing switch on. e. The synchroscope indicates the condition of the incoming machine with respect to the bus. If the frequency of the incoming machine is higher than that of the bus the synchroscope pointer will revolve in a clockwise or fast direction. The operator should adjust the governor control of the incoming prime mover until the synchroscope pointer is revolving slowly in the fast direction. The machines should be paralleled by closing the breaker of the incoming .