Generators

• Phase


  The distribution of a load in electricity
• Single-phase power


  • A two-wire alternating current (AC) power circuit with one power wire (the phase wire) and one neutral wire, with current flowing between the power wire (through the load) and the neutral wire
• Three-phase power


  • A three-wire AC power circuit with each phase AC signal 120 electrical degrees apart
• Single-phase power


  Does not offer the same consistency as three-phase power due to peaks and dips in voltage
• Three-phase power


  Delivers power at a steady, constant rate
• Shipboard electrical distribution components

  • Switchboard connection
  • Protective devices
  • Regulating device
  • Fuse block
  • Automatic bus transfer
  • Coaxial cable
  • Shielded wire
• Emergency generator


  A small separate generator which supplies the electric power for emergency load in the event of main power supply failure
• Emergency generator


  • Located outside the main and auxiliary machinery space and not forward of the collision bulkhead
  • Has own switchboard near vicinity
  • Provided with independent means of automatically starting (by air or battery) to ensure immediate run up following a main power failure and repeated starts of at least 3 times, and further attempt can be made within the 30 minutes
  • Adequate and independent supply of fuel with a flash point of not less than 43 °C
  • Must be able to be started in cold condition up to zero (0 °C)
  • For cold weather, JCW system must be treated with anti-freeze agent, and heating arrangement provided
• Emergency generator maintenance


  1. Test run every Saturday

  2. Air bottle pressed up or starter battery fully charged, at all-time

  3. Changeover the selector switch to local position before starting

  4. Make sure breaker switch at 'off' position before starting

  5. During testing, check frequency, voltage and ampere

  6. Fuel tank, always checked to ensure adequate level

  7. Air filter of generator, regularly cleaned

  8. Required tools and spares kept in a container

  9. Emergency light for this room should be always checked
• Emergency switchboard


  A switchboard which distributes emergency load that power is supplied from emergency generator during the main power source failure
• Emergency switchboard distribution


  • Emergency Bilge pump (440 V)
  • Sprinkler system (440 V)
  • One of the steering gears (440 V)
  • Navigation Equipment (220 V)
  • Radio Communication (220 V)
  • Transformed and rectified supply to Battery systems (220 V)
  • Transitional Emergency Power Battery (Emergency lights for 30 minutes)
  • Low power DC system Battery (Alarms and control system)
• Equipment supplied by emergency generator

  • Emergency lightening to alley way /boat deck / engine room
  • Navigation system
  • Steering gear
  • Emergency fire pump
  • Emergency air compressor
  • Battery charging
  • Fire detecting and alarming system
  • Radio equipments (Communication equipment)
  • Daylight signaling lamp and ship's whistle
  • Navigation Aids
  • General Alarm
  • Manual fire alarm
  • Watertight door
• Requirements/Regulations for emergency power

  • All passenger and cargo vessels shall be provided with emergency sources of electrical power, for essential services under emergency conditions
  • Emergency source may be generator or batteries, but must be complied with the rules
  • Emergency sources must be installed in position such that they are unlikely to be damaged or affected by any incident, which has caused to main power
  • Emergency source of power should be capable of operating with a list of up to 22 ½ ° and a trim of up to 10 °
  • Emergency generator with its switchboard, is located in a compartment which is outside and away from main and auxiliary machinery space, above the uppermost continuous deck, and not forward of collision bulkhead
  • For batteries, the above same rules applied, nut must not be fitted in the same place as emergency switchboard
• Passenger ship emergency power requirements

  • Emergency generator shall be automatically started and connected within 45 sec
  • Capable of supplying simultaneously at least the following services for the period of 36 hours: Emergency lightening, Fire detecting and alarming system, Internal communication equipments, Daylight signaling lamp and ship's whistle, Navigation equipment, Navigation lights, Radio installations, Watertight doors, One of the fire pumps, emergency bilge pump
  • A set of automatically connected Emergency batteries must be capable of carrying certain essential services for the period of 30 min: Emergency lighting, Navigation lights, Fire detecting and alarming system, Internal communication equipment, Daylight signaling lamp and ship's whistle
• Cargo ship emergency power requirements

  • Emergency generator shall be automatically started and connected within 45 sec
  • Emergency power source, Emergency generator must be sufficient to operate certain essential services at least for the period of 18 hours: Emergency lightening, Fire detecting and alarming system, Internal communication equipment, Daylight signaling lamp and ship's whistle, Navigation equipment, Navigation lights, Radio installations, One of the fire pumps, emergency bilge pump
• Battery requirements


  • Where emergency source of electrical power is an accumulator battery, it shall be capable of carrying loads without recharging and battery voltage throughout discharge period must be maintained within 12% above or below its nominal voltage
  • Battery system is automatically connected upon loss of main power
  • Batteries are required as transitional power source for 30 min for: Fire detecting and fire alarm, Emergency lightening, Navigation lights, Internal communication equipment
• Procedure for starting emergency generator in black outs

  1. Normally emergency generator cut in automatically when main power fails

  2. Starting is initiated by start up relay

  3. Falling of frequency or voltage of Main power, cause the start up relay to operate generator starting equipment

  4. If this system fails, after switching the MODE selector to Manual (Local) position, generator can be started manually by means of Back up starting equipment within 30 minutes of transitional emergency power battery lighting
• Emergency light maintenance


  1. Every Saturday, routine testing of emergency lights is carried out

  2. Ensure that batteries are fully charged and ready for use

  3. Burnt out bulbs replaced at once
• Places provided with emergency lighting


  • Engine room lighting
  • Bridge lighting
  • Passage way lighting
  • Embarkation light
• A rotating magnet called the ___ turns inside this stator producing magnetic field.

  Rotor
• The generator consists of a stationary set of conductors wound in coils on an iron core. This is known as the __

  Stator
• The __ __ __ __ a ship needs to be supplied efficiently throughout the ship

  Power Distribution on board
• Enclosure that houses various electrical instruments, indicating devices, protective devices, and regulating apparatus required for the control of the generators and for the distribution of electricity.

  Switchboard
• Contains buswork and distributes electrical power from generator to various circuits

  Switchboard
• An electrical protective device consisting of a fusible (easily melted) metal-alloy strip of wire encased in a cartridge.

  Fuse
• Protects the circuit/equipment from possible damage due to excessive current

  Fuse
• An electrical device that opens due to various trip setpoints (over-current, under- voltage, under-frequency) to protect generators and loads

  Circuit Breaker
• __ may be operated manually or electrically, and can be used as switches in some circuits

  Circuit Breaker
• A device that senses a loss of power from a normal (N) source and will automatically disconnect the load from the normal source and connect it to an alternate (A) source

  Automatic Bus Transfer (ABT)
• Can connect a load to either a normal (N) or alternate (A) source, but unlike ABTS (which shift automatically) must be shifted manually

  Manual Bus Transfer (MBT)
• Electrical power is distributed as follows:

  Generators Distribution switchboards Load centers Distribution panels Loads
• Emergency (E) power is normally supplied by two or more __ __ __ which will start automatically upon a loss power to the SSDS


  Emergency Diesel Generators (EDGs)
• __ systems optimize continuity of power (increase equipment reliability), but do not increase personnel safety

  Ungrounded
• Shipboard electrical power is __

  ungrounded
• Emergency Generators should be capable of giving power for a period of __ hours for a cargo ship and __ hours for a passenger ship.

  18 and 36
• Shipboard power is generated using a __ and an __ working together.

  Prime Mover and an Alternator
• __, 3 phase power is preferred over DC as it gives more power for the same size.

  AC
• ___ is preferred over single phase as it draws more power and in the event of failure of one phase, other 2 can still work

  3 Phase
• Act as a carrier and allow transfer of load from one point to another.

  Bus Bars
• Act as switch unsafe and a in condition can be tripped to avoid breakdown and accidents.


  Circuit Breakers