T.S. Patriot State Engineering Manual

Patriot State was the training ship of the Massachusetts Maritime Academy from 1986 to 1998.

Electrical System Operation

Generators shall be not paralleled or disconnected from the bus, and electric power shall not be shifted from shore power to ship's power or vice versa except under the direct supervision and control of the ship's Electrical Officer, Chief Engineer, First Assistant Engineer or Second Assistant Engineer. There are no exceptions.

Turbogenerator Start-up

  1. Check over the unit.
    1. Check the oil level in the sump. Make sure that the temperature of the oil in the sump is at least 60°F.
    2. Look around the unit for rags, loose parts, leaks, etc.
    3. Trip and reset the emergency trip mechanism.
  2. Establish cooling water flow through the condenser.
    1. Open the auxiliary circulating pump suction, and the inlet and outlet valves on the condenser, leave the circ pump discharge valve closed until the pump is started.
    2. Start the pump.
    3. Open the auxiliary circulating pump discharge valve. Opening the discharge valve on centrifugal pumps after the pump has started is good engineering practice, because it reduces the starting load on the drive motor. Also, in this case, if the pump is completely lined up before it is started, pressure from the other circulating pumps will cause the pump to spin backwards, further increasing the starting load on the motor.
  3. Establish cooling water flow through the auxiliary air ejector. The air ejector is cooled with condensate from the auxiliary condenser. Before the turbine is started, and when it is operating under low loads, there is a shortage of condensate. This shortage is made up by recirculating the condensate
    1. Open the condensate outlet valve on the auxiliary air ejector condenser.
    2. Open the condensate pump vent. (No valve on Patriot State)
    3. Open the recirculating line.
    4. Start the condensate pump, and open the condensate pump discharge valve.
    5. Watch the level in the hotwell, and adjust the recirc flow to keep the level low or empty. If the recirc valve is left open while the condensate pump is not pumping, or is open too wide, the hotwell will fill up and overflow through the turbine bearings.
  4. Raise vacuum.
    1. Open the two gland sealing valves for the turbine, and the gland leakoff valve. Sealing steam comes from the auxiliary exhaust system, and should be maintained at 1-2 psi at the glands.
    2. Line up the air ejector by opening the vapor suction line and cutting in steam to the second stage only. Vacuum should rise rapidly to 20" Hg.
    3. When the vacuum has reached 20", cut in the first stage and bring vacuum up to 29" Hg.
  5. Spin the turbine. The turbine should be started spinning without delay after the vacuum is established to prevent the rotor from standing still in a hot environment, which would cause the rotor to bow and cause vibrations.
    1. Crank the throttle valve hand wheel fully clockwise. This action sets the tripping mechanism.
    2. Crack open the drain ahead of the throttle and slowly open the steam root valve. When line to the throttle is warmed, drained and up to pressure, close the drains.
    3. Hand crank the oil pump to establish oil pressure. Watch for the governor power piston to rise and then slowly open the throttle until the turbine starts rolling. When the internal oil pump begins to deliver oil, you can stop hand cranking.
    4. Slowly increase the steam to the turbine to bring it up to speed. Watch the governor to see that it takes over. When it has, open the throttle wide. It is possible to overspeed and trip the generator if it is brought up too fast.
  6. Watch the unit carefully.
    1. Walk around the generator and check for any problems such as lube oil leaks or unusual noises. If in doubt, shut the unit down.
    2. Keep you eye on the vacuum, oil pressure and temperature, and air box temperature.
    3. Allow the turbine to idle for about 30 minutes if possible, or at least until the oil temperature reaches 100°F.
    4. When the oil temperature comes up, start cooling water to the lube oil cooler, and adjust to maintain 110° F.
    5. Adjust the cooling water flow to the air box to maintain 40° C.
    6. When you are satisfied with the operation of the turbo-generator, you can put it on the line.

Generator Paralleling

This procedure assumes that one generator is already on the line, and that the prime mover is up to speed and ready.

  1. Adjust generator to produce correct voltage, phase, and frequency.
    1. Place the voltage regulator cutout switch to the "automatic" position.
    2. Check the generator voltage by placing the voltmeter transfer switch in the "generator" position and read the voltmeter. Adjust the voltage adjusting rheostat until the oncoming generator's voltage is slightly above bus voltage.
    3. When the desired voltage is obtained, turn the voltage regulator to automatic.
    4. Turn the frequency meter switch to the "bus" position and check the frequency of the bus on the frequency meter.
    5. Turn the synchroscope to the proper position for the oncoming generator.
    6. Observe the synchroscope and adjust the governor control until the synchroscope pointer is rotating slowly in the clockwise direction. This will insure that when the oncoming generator is connected to the bus it will pick up a small portion of the load. If the synchroscope pointer is rotating in the counterclockwise direction, the generator will become motorized and may trip the reverse power relay. If the synchroscope pointer is rotating too fast in the clockwise direction, the generator will assume too much load and could trip.
  2. Connect the generator to the bus.
    1. Close the generator circuit breaker when the synchroscope is 1 or 2 °ees before the 12 o'clock position. This connects the oncoming generator to the bus.
    2. Turn the synchroscope to the "off" position.
  3. Balance the loads.
    1. Division of load between a.c. generators operating in parallel is a function of the power input to the generators. So, the governor control switches are used to balance load. Adjusting the governor control switch in the "raise" direction causes that generator to pick up load, and "lower" causes it to shed load. While turning the governor control switches, the wattmeter of both machines must be observed until the load is balanced between the two generators.
    2. Next balance the inductive load (amperes) using the voltage adjusting rheostat of the generators.
    3. If the load is balanced with rated voltage and frequency being generated, the paralleling operation has been successfully completed.
    4. Continue to maintiain a good watch on all operating equipment.

Generator Shut Down

  1. Reduce the load

    If the generator is tripped off while still supplying a large load, the circuit breaker contacts are subjected to severe induced arcing and may be damaged.

    If the machine is operating alone, you can reduce the load by securing lights, pumps, and other loads being supplied by the generator.

    If the generator is operating in parallel, you must still unload it before it is secured, but you don't want to lose other equipment that is being supplied. Therefore, you must shift the load from one generator to another. First, it must be determined if the generator that is to remain on line will safely supply the load. The generators on this ship will provide 750 kilowatts and 1250 amps. If the remaining generator does not have the capacity to supply the load, the load must be reduced until it can. This is most easily done by securing all unjustified loads and non vital loads. Once it has been established that the remaining generator will supply the load, the load can be safely shifted to the remaining generator.

    To shift the load, turn the governor motor control switch of the generator to be secured in the "lower" direction, while simultaneously turning the remaining generator's governor motor control switch in the "raise" direction. By observing the wattmeters, continue to shift load until the generator that is to be secured is carrying only a very small load. It is important not to go beyond the zero mark on the wattmeter. If this happens, you are now motorizing the generator and also drawing power from the remaining generator. The small load that is left on the generator that is being secured can easily be picked up by the remaining generator with little sudden stress. This procedure is called "sneaking off a generator" and is the safest way to load and unload generators during a parallel condition securing operation.

  2. Disconnect the genertor from the switchboard electrically.
    1. Trip the generator circuit breaker that is being secured by pushing the "trip" button which is located near the operating handle of the circuit breaker.
  3. Secure the prime mover.
    1. Trip the throttle valve. Take low oil pressure alarm and generator trip switch circuits out of service.
    2. Shut off water flow to the oil cooler and to the generator air cooler. Drain the water from the coolers.
    3. When the stop valve ahead of throttle valve is closed, open the drain ahead of the throttle valve to relieve pressure and to drain the line.
    4. Secure steam to the air ejector and the condensate pump. Break vacuum in air ejector.
    5. Shut off steam supply to the packing gland sealing system at 5" Hg.
  4. Keep an eye on the unit
    1. Let the circulating pump continue in operation for about 30 minutes to cool the unit and draw out all vapor . Secure the circulating system.
    2. When the turbine is shut down, take every precaution to guard against steam leaking into the turbine casing as a protection against corrosion of the internal ports.
    3. If the hotwell is filling up rapidly, check that the recirc valve is closed.

Shifting from Shore Power to Ship's Power

  1. The ship's auxiliary plant will be started and one turbo generator brought up to speed. When the generator is ready in all respects, first check the amperage being drawn on the shore power ammeter. If the load is in excess of 600 amps, strip equipment off the board until the load is reduced. Selectively start with white handled (non vital) switches.
  2. Parallel the generator with shore power by using the manual voltage regulator and matching voltages. Control the synchroscope until it is slowly rotating clockwise. Check the synchronizing lights and have the cycles at 60+. As the synchroscope slowly rotates clockwise, close the generator circuit breaker at the "11 o'clock" position.
  3. Put the voltage regulator in "auto" and increase the load on the ship's generator until it is taking approximately the same amperage as the shore power.
  4. Open the ship's shore power breaker and tag it. Stabilize plant operation. NOTE: The shore power cable can be left connected and energized to be available if needed up until a few hours of getting underway.
  5. When the plant has stabilized and the shore power cable is to be removed, the shore power breaker on the dock is opened and tagged. At Buzzards Bay, Facilities personnel have the keys to the building where the breaker is located.
  6. At this point, test for voltage on all phases in the ship's shore power cabling, connection box to insure that there is no voltage.
  7. Disconnect the shore power cables from the ship's shore power connection box and coil the cables on the rack ashore. Wrap conductor ends to make them weather tight. Replace the ship's connection box cover and store all tools.
  8. Set up the emergency diesel generator by turning the start switch to "on" (no. 9, 120 vdc panel).

Shifting from Ship's Power to Shore Power

NOTE: It is not possible to parallel shore power to the ship's system and it should not be attempted.

  1. Check the appropriate shore power circuit breaker in the engine room and insure that it is opened and tagged.
  2. Unlock the pier building and insure that the shore power breaker is opened and tagged.
  3. Check for voltage at the shore power cabling connections on the ship and the dock. Insure that there is no voltage.
  4. Connect the shore power cables to the shore side connection and bring the other end aboard ship. Do not connect up.
  5. In order to insure the phase sequence is correct when the power is energized (so ship's motors won't run backwards):
    1. Connect a phase sequence meter at the ship's shore power cable connections. Mark shore power lugs to correspond with the leads on the meter, if not already so marked.
    2. Stand well clear and close the engine room shore power breaker and note the phase rotation and power to all three phases.
  6. Open the engine room shore power breaker and test all three phases on the shore power connection to insure that there is no voltage.Double check the shore power cables to insure there is no voltage.
  7. At this point:
    1. The engine room shore power breaker is open.
    2. The shore side shore power breaker is open.
    3. There is no voltage present in the ship's connection box or the shore power cable.
  8. Connect the shore power cable to the ship.
  9. In order to insure the phase sequence will be the same as the ships when the power is energized.
    1. Connect the phase sequence meter at the ship's shore power cable connections as before using previous marks as a guide.
    2. Stand well clear and close the shore power breaker on the dock. Note the phase rotation and power to all three phases. If the rotation is not the same as when previously checked, secure the shore power breaker and reverse any two leads.
  10. After the rotation has been shown to be correct and the shore power breaker on the dock is secured, check connection to insure there is no voltage and remove the meter. Check all connections for tightness and replace the ship's shore power box cover.
  11. Close the shore power circuit breaker on the pier and the indicator light above the ship's connection box will light indicating power available. The shore power available light on the main board will also be lit.
  12. Place the emergency diesel generator, start switch in "off" position (no. 9, VDC panel). Pass the word "ship's power will be interrupted in five minutes while shifting to shore power."
  13. Reduce the electrical load on the ship's generator to the minimum.
  14. Trip the ship's generator off the board. (No lights or power on board.)
  15. Close the ship's shore power breaker. Restart auxiliary machinery that was previously running. Reclose the emergency bus tie breaker. Put it back on normal power.

Direct comments to William Haynes whaynes@maritime.edu
Mon, Jul 1, 1996
TSPS Engineering Manual ©1995 Massachusetts Maritime Academy