In Marine Industries the electrical equipment which are used are differ from the electrical equipment used shore based or land installted because of the different reason :- Climate Condition, vibration, the continuous motion of ship, temperature and condition of uses.
Effect of Inclination:-
– According to SOLAS Regulation of Machinary Installations – “Main propulation and all auxilary machinery to the ship is capable of operating when the vessel is upright and when inclined at any angle of list up to and including 15′ either way under static conditions and 22.5′ under
dynamic conditions (rolling) either way and when simultaneously inclined dynamically (pitching) 7.5′ by stern.
Effect of Temperature :-
Extremes of temperature will effect the performance and the effective life of any electrical apparatus. Devices which depends on electromagnetic operation by shunt coils will find that the resistance of the coil increases with temperature and so with less current, the field strength is reduced. Tempature also affect the life of insulation of elctrical appliance or wires.
Suppiers and Users :-
A ship electrical system can be divided into “suppliers” and “users”
Now the Suppliers or Generation covers :-
- Prime Movers
- Starting Arrangement
- Control Device to maintain correct the value of speed, frequency and voltage
And the Distribution Covers:-
- Main Switchboards
- Auxilary Switchboards
- Section Switchboards
- Starter Panel
- Circuit Breaker
- Switches, fuses, etc.
And the user or Consumer includes :-
- Motor driving machines
- Heating Installation
- Lightening Circuits
Primary Essential Service :-
Primary Essential service are those which are need to be in contionous operation for maintaining propultion and steering. which are:-
- Sterring Gears
- Pumps for Controllable pitch propellers
- Scavenging air blower, fuel oil supply pumps, fuel valve cooling pumps, lubricating oil pumps and cooling water pumps for main and auxiliary engines and turbines necessery for propulsion.
- Ventillation necesssary to maintain the proplusion
- Forced draft fan, feed water pumps, water circulating pumps , vaccum pumps and condensate pumps for steam plants on steam turbine ship
- Oil burning installations for steam plants on steam turbine vessels and for auxiliary boilers where steam is used for equipment supplying primary essential service.
- Azimuth thrusters which are the sole means of propulsion plant and lubricating oil pumps and cooling water pumps.
- Electrical generators and associated power sources suppling primary essential equipment.
- Hydraulic pumps and suppling primary essential equipment.
- Viscocity Control Equipment for heavy fuel oil.
- Control, monitoirng anf safety devices/ systems of equipment for essential sevices.
- Fire detection and alarm system.
Secondry Essential Service :-
This are not need to be in contionous operation which are as follow :-
- Fuel oil tranfer pumps and fuel oil treatment equipment
- Lubrication oil tranfer pumps and its treatment.
- Pre-heaters for heavy fuel oil.
- Starting air and oil control air compressor.
- Bildge,ballast and heeling pumps.
- Fire pumps and other fire extinguishing ,medium pumps
- Ventiallating fans for engine and boiler rooms.
- Navigation lights, aids and signals
- Internal communication equipment
- Lightening System
- Electrical equipment foe watertigth and firetight closing aplliances
- Hydraulic pumps suppling secondry essential equipment
- Ambient temperature control equipment
- Other truster like boosters, etc