Ø QUE-ANS:10-30 words
[1] When must an emergency power source some on line?
An emergency power source must come on line when following a total electrical failure.
[2] Why are both an emergency generator and batteries recommended?
Both an emergency generator and batteries are recommended so that at the moment of total power failure there is not a black out, as a battery supply will instantaneously supply power to lighting.
[3] How long must battery powered lightening run on passenger ships?
On passenger vessels, battery powered lighting must be able to run for a minimum of 3 hours.
[4] When is the testing of emergency power supplies done?
Testing of emergency power supplies are done weekly on a normal basis where practical.
[5] What are the special interlocks fitted to the main and emergency generation circuit breakers for?
The special interlocks that are fitted to the main and emergency circuit breakers are interlocks that prevent parallel running of the emergency and ships generators as it is not normally possible to synchronize them.
[6] What are two methods of auto-starting an emergency generator?
The two most common methods of automatically starting an emergency generator are by compressed air and battery.
[7] How is the auto-start tested?
The auto start can be tested by simulating a power failure by pulling a fuse in the auto start panel which supplies the under voltage or under frequency relay.
[8] What is the only way to test the performance of the emergency power supply?
The only way to test the performance of an emergency generator is to give it a proper load test by means of disconnection of normal mains power.
[9] What equipment is usually fed by batteries?
Equipment normally fed by batteries are; emergency lighting, emergency generator starting, radio equipment, navigation lighting, alarm panels, communications.
[10] What is the supply given to shipboard general alarm?
24v dc
[11] Where from you get the supply for emergency loads during normal voyage?
From ship’s service alternator through emergency switch board’ a tie breaker is fitted between the main switch board and the emergency switchboard.
Ø 30-60 words
[1] What is done to ensure the Emergency Generator is Always Available and Will Start?
The System should be checked regularly and operated weekly to ensure it’s availability if required. Fuel tanks should be kept full, ample cooling water in radiator cooling system and starting equipment should be functional, i.e. batteries should be fully charged or air receivers full
[2] Why emergency source of electrical power is provided?
Emergency source of power supply is provided so that in the event of an total power failure, A supply will still be available for emergency lighting, alarms, communications, water tight Doors and services necessary to maintain safety.
[3] Why must an emergency electrical power system be proved?
An emergency electrical power supply must be provided so that in the event of an emergency involving total power failure, a supply will be available for emergency lighting, alarms, communications, watertight doors and other necessary services to maintain safety and to permit safe evacuation of the vessel to lifeboats.
[4] What is done to ensure the Emergency Generator is Always Available and Will Start?
The System should be checked regularly and operated weekly to ensure it’s availability if required. Fuel tanks should be kept full, ample cooling water in radiator cooling system and starting equipment should be functional, i.e. batteries should be fully charged or air receivers full.
[5] What are the Essentials supplied by the Emergency Switchboard?
Essentials are: Emergency Lighting, Alarms, Communications, Watertight Doors and other services necessary to maintain safety and to permit safe evacuation of the Ship by Lifeboats. Also you will find that a Steering Gear Motor, Emergency Air Start Compressor and Emergency Fire Pump Motor are supplied from the Emergency Switchboard.
[6] State the danger arising from reducing the excitation of the outgoing generator before it is off loaded.
When the excitation of the outgoing generator is reduced, the current taken by it is reduced. The current (load) of the other generator is thus increased and if exceed the rated current, the overload relay will trip the generator and a blackout would occur.
[7] Briefly describe how a running AC generator would be taken off load and another generator put on load without a blackout.
The incoming generator is synchronized with the running generator after having ensured that the frequency and voltage of both generators are identical, both having the same phase sequence and the phase angle difference between the voltages is zero. To minimize the possibility of blackout, both generator should be allow to run in parallel for a short time before taking the outgoing are off load.
Ø 100-150 words
[1] What are the Essentials supplied by the Emergency Switchboard?
Essentials are: Emergency Lighting, Alarms, Communications, Watertight Doors and other services necessary to maintain safety and to permit safe evacuation of the Ship by Lifeboats. Also you will find that a Steering Gear Motor, Emergency Air Start Compressor and Emergency Fire Pump Motor are supplied from the Emergency Switchboard.
They are used for supplying essential power to: Radio Equipment, Telephone Exchange, Fire Detection, General Alarm Circuits, etc. These Systems are often supplied from two sets of batteries worked on a regular charge/discharge cycle.
They are also used as Emergency Supplies, i.e. for Emergency Generator Start-up and Emergency Lighting. Being used in this case in a “stand-by” role to give power when Main Supplies fail.