Generating and distributing power
- The generators or alternators, the main switchboard, distribution and protection (fuses and circuit breakers).
- The battery systems, their charging, and the emergency and essential electrical supplies.
- Safe isolation, the recognition of earth faults, and basic testing with instruments.
- Electrical safety and the real dangers of working on live equipment.
Electrical power is generated by the vessel's generators and distributed through the switchboard to the ship's services, protected against overload and fault by breakers and fuses. The engineer must know how to isolate a circuit safely and prove it dead before working on it, recognise an earth fault, and never work on live equipment without the proper precautions. Electricity is an invisible hazard, and most electrical accidents come from working on equipment that was not properly isolated.
WARNING — Isolate and prove dead before working Before working on an electrical circuit, isolate it and prove it dead with an approved tester. Working on equipment assumed to be dead, but not proved, is how electrical accidents happen.
NOTE — Watch for earth faults An earth fault does not stop the system at once but is a warning: a second fault can then cause a short circuit or a shock. The engineer finds and clears earth faults promptly rather than living with them.