All SOLAS vessels need to be equipped with a self-contained emergency source of power supply, with sufficient capacity to supply all services essential for safety in an emergency.  The emergency power source shall be automatically connected to the emergency switchboard in case of failure of the main power supply. It shall supply the required services within 45 seconds. The emergency power source shall not be used as power source during normal operation. For exemption it can be used for powering up from dead ship and for routine testing. //SOLAS Ch.II-1/43.1.2, 43.3.2.1-3 and  DNV-RU-SHIP Pt.4 Ch.8 Sec.2.3.1.1

The emergency power system shall be located above the upper most continuous deck, behind collision bulkhead and be accessible from open deck. Where the emergency source of electrical power is a generator, it shall be driven by a suitable prime mover having an independent supply of fuel with a flashpoint of not less than 43°C and shall have auxiliary systems e.g. cooling system, ventilation and lubrication operating independently of the main electrical power system. The prime mover shall start automatically in case upon failure of main power supply. An alarm indication for emergency source of power not ready for immediate starting shall be arranged in engine control room. If the generator breaker has a test position, this shall be recognized by the control system as not available. // SOLAS Ch.II-1/43.3.1.1, DNV-RU-SHIP Pt.4 Ch.8 Sec.2.3.1.1, Pt.4 Ch.8 Sec.2.3.3 and Pt.4 Ch.8 Sec.2.8.3

Emergency generating set shall be capable of starting from cold condition at temperature of 0 ⁰C. If this is impractical or the vessel is operating in colder conditions a heating arrangement shall be provided. The starting device for emergency generator shall have stored energy capacity for at least three consecutive starts. A second source of energy shall be provided for an additional three starts within 30 minutes, unless manual starting can be demonstrated to be effective within this time. One starting motor is sufficient. Stored energy for starting shall be maintained at all times and shall be powered from the emergency switchboard. All starting, charging and energy storing devices shall be located in the emergency generator room. Compressed air starting systems may however be maintained by the main or auxiliary compressed air system through a suitable screw-down non-return valve fitted in the emergency generator space. //SOLAS Ch.II-1/44.1-2, SOLAS Ch.II-1/44.3 and DNV-RU-SHIP Pt.4 Ch.8 Sec.2.3.3.3

Protective shutdown functions for emergency generator sets shall be limited to short circuit. Other protective functions, such as overcurrent, high temperature etc. shall give alarm only. Such alarms are recommended to be given at manned control station. Any cool down function (or similar) shall not prevent immediate start of stopped emergency generator set. If emergency generator runs parallel to any other power source a shut down or stop signal for the prime mover shall cause disconnection signal to generator circuit breaker. //DNV-RU-SHIP Pt.4 Ch.8 Sec.2.3.3.3

The emergency generator shall have means for manual operation. The generator circuit breaker shall be provided with automatic wind up of the closing spring of the breaker. Automatic connection of the generator during blackout shall only be possible when auxiliary contacts on the incoming feeder breaker show directly that all power supply is disconnected from the emergency switchboard and the bus is dead. Automatic connection of generator shall not take effect before the voltage of the generator is stable and at normal level. For emergency generators, a trip of a control circuit protection shall not lead to uncontrolled closing of the generator breaker against a live bus. //DNV-RU-SHIP Pt.4 Ch.8 Sec.2.8.3

The emergency generator may be used as harbor generator supplying ship’s main electrical system during port stay, provided that the requirements for available emergency power are adhered to all times. The prime mover shall be arranged with fuel oil filters and lubrication oil filters, monitoring equipment and protection devices as required for the prime mover for main power generation and for unattended operation. Overcurrent or overload shall trip the feeders to the main switchboard. A tank level alarm shall be installed on fuel supply tank at a level ensuring sufficient fuel capacity for the emergency services for the required time. Fire detectors shall be installed in emergency generator room. Instructions shall be provided on board to ensure that when the vessel is under way all control devices (e.g. valves, switches) are in a correct position for the independent emergency operation of the emergency generator set and emergency switchboard. These instructions are also to contain information on required fuel oil tank level, position of harbor or sea mode switch if fitted, ventilation openings, etc.  //DNV-RU-SHIP Pt.4 Ch.8 Sec.2.3.3.4
In case non-emergency consumers are connected to the emergency switchboard, the capacity of emergency generator shall be enough to supply all the consumers at the same time, or an automatic disconnection of non-emergency consumers upon start of emergency generator shall be arranged. The capacity needs to be enough that the largest emergency consumer can be connected at any time without overloading the emergency generator. //SOLAS Ch.II-1/43.5.5 and  DNV-RU-SHIP Pt.4 Ch.8 Sec.2.3.1.1

Last modified: Thursday, 4 May 2023, 4:34 PM