tailieunhanh - OPERATION, MAINTENANCE AND REPAIR OF AUXILIARY GENERATORS Episode 8

Tham khảo tài liệu 'operation, maintenance and repair of auxiliary generators episode 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | TM5-685 NAVFAC MO-912 various relays and indicating lights associated with the control circuitry. The control circuits are classified as either AC or DC. 1 ACcontrol circuits. AC control circuits usually derive their power from the source side of the circuit breaker being controlled. This procedure applies to main incoming line circuit breakers generator circuit breakers and feeder circuit breakers see fig 5-6 . Depending on the system voltage the control power can be taken directly from the main bus since it can be connected through a control power transformer. 2 Tie breaker control circuits. In systems using a tie breaker the control power for the tie breaker and the feeder breakers is supplied through a throw-over scheme so control power is available if either side of the tie breaker is energized see fig 5-7 . In applications that require synchronizing circuitry the running and incoming control buses are usually supplied via the potential transformers. The transformer primaries are connected to both the line side and the load side of the circuit breakers that are used for synchronizing. The transformer MAIN INCOMING LINE GENERATOR FUSE CONTROL POWER TRANSFORMER FEEDER BREAKER Figure 5-6. AC control circuits. CONTROL POWER TRANSFORMER CONTROL POWER BUS GENERATOR BREAKER IZ CONTROL POWER -transformer FUSE LOAD LOAD FEEDER BREAKER 5-6 TM 5-685 NAVFAC MO-912 Figure 5-7. AC control circuits with tie circuit breaker. secondaries are connected to the proper control bus through contacts on the synchronizing switch or through contacts on certain auxiliary relays. The synchronizing switch would be used for manual operation and the auxiliary relay would be used when automatic synchronizing is provided. 3 DC control circuits. DC control circuits derive their power from a battery source consisting of a bank of batteries and a battery charger that maintains the batteries at the proper charge. The battery bank can be rated at various levels ranging between 24 volts and 125 .