ships, voltages upto and equal to 1000 volts is called as low voltage system and voltages above 1000 volts is called high voltage system. Normally low voltage system is common on b... Read more
There are three types of overcurrent relay (OCR) used for motor protection: Electronic Thermal Electromagnetic Electronic OCIT (overcurrent inverse time) relays have largely supers... Read more
The standard cage-rotor a.c. induction motor operates as an almost constant speed drive over its load range. This feature is satisfactory for most of the ship’s auxiliary ser... Read more
The induction motor has two main components, the stator and the rotor. The stator carries three separate insulated phase windings which are spaced 120 degree (electrical) apart and... Read more
LV generator circuit-breakers and other large distribution circuit-breakers (600-6000 A) on board ship are traditionally of the air break type called ACB (air circuit breaker). Thi... Read more
The central section of the main switchboard is used for the control of the main generators. The switchgear cubicles on either side of the generator panels are used for essential se... Read more
Regular inspection and the correct maintenance of generators and their associated control gear is essential to prevent failure and inefficient operation. Always ensure that the gen... Read more
An undervoltage (U/V) release mechanism is fitted to all generator breakers and some main feeder circuit-breakers. Its main function is to trip the breaker when a severe voltage di... Read more
The general term “overcurrent” applies to a relatively small increase over the full load current (FLC) rating (e.g. due to mechanical overloading of a motor) rather tha... Read more
Ships’ staff must operate equipment in a safe manner and maintain it in a safe condition at all times. Failure to do so will cause danger with serious consequences arising. K... Read more
