EMERGENCY GENERATOR
SOLAS Requirements
Emergency generator and ESB should be located above the uppermost continuous deck, not forward of collision of bulkhead.MSB or any machinery space should not interface with the supply control and distribution of emergency...
SHAFT DRIVEN GENERATOR ARRANGEMENT
The a.c. shaft generator is a synchronous machine which produces alternating current with a frequency that is dictated by variations in engine speed. At the full rated r.p.m., frequency may match with the electrical...
MOTOR STARTING METHOD
Star Delta Starter
This
is means of reducing
starting current of induction motor by initially connecting to the stator winding to ‘STAR’.
Once
the motor comes up to
speed (68%) to be connected
in DELTA.
When
motor start in ‘STAR’
it has the effect
of:
Reducing...
SHORE ELECTRICAL SUPPLY
A shore supply is required so that the ships generators and their prime movers can be shut down for major overhaul during a dry dock period.
Requirements/Checks
There must be a suitable connection box conveniently located...
BRUSHLESS ALTERNATOR
In
this machine slip-rings
and brushes are eliminated and excitation is provided not by conventional direct
current exciter but by a
small alternator.
The a.c. exciter has the unusual arrangement of 3phase output windings on the rotor and magnetic...
ELECTRIC PROPULSION
An electric propulsion system for a ship is often simply described as a diesel electric or turbo electric system. It is characterised only by the type of prime mover, with no reference to the...
AUTOMATIC VOLTAGE REGULATOR
Sudden load current surges (eg. Due to motor starting) on a generator causes a
corresponding change in its output voltage. This is due to an internal voltage drop in
the generator winding and effect is called...
TAILSHAFT SURVEY
Different types of surveys
Normal survey : These are the conventional survey processes in which the tail- shaft is completely withdrawn at intervals as detailed in Table:1 and thoroughly examined to the satisfaction of the
Recognised...
NOx REDUCTION TECHNOLOGIES
Industrial Sources The three major primary sources of NOx, in combustion processes:
Thermal Nox - Formed when nitrogen and oxygen in the combustion air supply combine at high flame temperatures. Thermal NOx is generally formed...
REFRIGERATION AND AIR CONDITIONING
Refrigeration Cycle
Compression
The function of a compressor is to raise the pressure of a refrigerant vapour, by compressing the vapour. With the function of the compressor, a refrigerant carries heat from low temperature region to...