An article published in Marine Engineering Online, briefs about the emergency generator.
Here is an excerpt from that.
What is an Emergency Generator?
Emergency Generator is a small separate generator that supplies the electric power for emergency load in the event of main power supply failure.
Where is it located?
It is located outside the main and auxiliary machinery space and not forward of the collusion bulkhead.
Auto switch on
It has its own switchboard near the vicinity. It is provided with independent means of automatically starting (by air or battery) to ensure immediate power back up following a main power failure and repeated starts of at least 3 times, and further attempt can be made within the 30 minutes.
Supply of fuel
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
- Once in every week, emergency generator must test run
- Air bottle pressed up or starter battery fully charged, at all-time
- Changeover the selector switch to local position before starting
- Make sure breaker switch at ‘off’ position before starting (an interlock between E/R Main switchboard breaker and emergency switchboard breaker is provided to prevent simultaneous closure of both breaker)
- During testing, check frequency, voltage and ampere
- Fuel tank, always checked to ensure adequate level
- Air filter of generator, regularly cleaned
- Required tools and spares kept in a container
- Emergency light for this room should be always checked
What is an emergency switch board?
- Emergency switchboard is the one that distributes emergency load that power is supplied from emergency generator during the main power source failure.
- It has two sections- one for 440V and another is 220V.
- Under normal condition, 440 V supply is taken from E/R Main Switchboard, through a Circuit BreakerWhen main power is lost, this Circuit breaker is tripped (opened)
- Emergency generator comes into action, and supplies power through another circuit breaker
- An interlock is provided, to prevent simultaneous closing of both breaker (both main and emergency generator may be running, simultaneously)
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 that gets supply from emergency generator
- Emergency lightening to alley way /boat deck / engine room.
- Navigation systemSteering gear
- Emergency fire pump
- Emergency air compressor
- Battery charging
- Fire detecting and alarming system
- Radio equipments (Communication equipment)
- Daylight signalling lamp and ship’s whistle
- Navigation Aids
- General Alarm
- Manual fire alarm
- Watertight doors
Emergency power sources on ships
Requirements & Regulations
- 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.
Rules and Regulations
Passenger ship
- 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 (at alley way, stairways and exits, muster and embarkation stations, machinery space, control room, main and emergency switchboard, firemen’s outfits storage positions, steering gear room)
- Fire detecting and alarming system
- Internal communication equipments
- Daylight signaling lamp and ship’s whistle
- Navigation equipment
- Navigation lights
- Radio installations, (VHF, MF, MF/HF)
- 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 signalling lamp and ship’s whistle
Cargo Ship
- 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 (at alley way, stairways and exits, muster and embarkation stations, machinery space, control room, main and emergency switchboard, firemen’s outfits storage positions, steering gear room)
- Fire detecting and alarming system
- Internal communication equipment
- Daylight signalling lamp and ship’s whistle
- Navigation equipment
- Navigation lights
- Radio installations, (VHF, MF, MF/HF)
- One of the fire pumps, emergency bilge pump
Rules and Regulations for Batteries
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 following items:
- Fire detecting and fire alarm
- Emergency lightening
- Navigation lights
- Internal communication equipment
Procedure for starting emergency generator when blackout occurs
- Normally emergency generator cut in automatically when main power fails
- Starting is initiated by start up relay
- Falling of frequency or voltage of Main power, cause the start up relay to operate generator starting equipment
- 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
- Once in every week, routine testing of emergency lights is carried out.
- Ensure that batteries are fully charged and ready for use.
- Burnt out bulbs replaced at once.
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Source: Marine Engineering
