1. Briefly describe the precautions for ship dock repair and shore power connection.
1.1. It is necessary to confirm whether the shore power voltage, frequency, etc. are the same as those on the ship, and then check whether the phase sequence is consistent through the phase sequence indicator light/meter on the shore power box (the wrong phase sequence will cause the motor running direction to change);
1.2. If the shore power is connected to the ship’s three-phase four-wire system, the insulation meter will be zero. Although it is a normal state, attention should be paid to the actual grounding fault of the electrical equipment on the ship.
1.3. The shore power of some shipyards is 380V/50HZ. The pump speed of the connected motor decreases, and the pressure of the pump outlet will drop; the fluorescent lamps are difficult to start, and some will not light up; the amplifying components of the regulated power supply electronic circuit may be damaged, such as If there is no data stored in the memory element, or there is a battery backup power supply, the AC part of the power supply can be temporarily turned off to protect the regulated power supply electronic board.
1.4. It is necessary to be familiar with all the switches of the ship and shore power conversion in advance. After making preparations for the shore power and other wiring, put all the main and emergency generator switches on the ship to the manual position, and then stop to replace the shore power, and try to shorten the time for power exchange ( Fully prepared can be done in 5 minutes).
2. What are the interlocking protection functions between the main switchboard, the emergency switchboard and the shore power box?
2.1. Under normal circumstances, the main switchboard supplies power to the emergency switchboard, and the emergency generator set will not start automatically at this time.
2.2. When the main generator trips, the main switchboard loses power and the emergency switchboard has no power, after a certain delay (about 40 seconds), the emergency generator automatically starts and closes, and sends to important loads such as radar and steering gear. and emergency lighting.
2.3. After the main generator resumes power supply, the emergency generator will automatically separate from the emergency switchboard, and the main and emergency generators cannot be operated in parallel.
2.4. When the main switchboard is powered by the onboard generator, the shore power circuit breaker cannot be closed.
Post time: Mar-28-2022