MODU Requirements for Electrical Installation

Main Electrical Installation

• The offshore unit's main electrical installation must provide power to all normal operation services without resorting to emergency power. These services include propulsion, safety, cooking, heating and refrigeration services. Also, key systems, such as the rudder angle and sliding watertight door position indicators, must have an automatic change-over to the emergency electrical power source. This guarantees the navigation and structural integrity of the unit is maintained during a power outage.

Hazardous Areas

• Install only essential electrical equipment in hazardous areas, such as battery rooms and paint, flammable liquid and gas cylinder storage areas. This reduces the risk of fire in areas where there is a risk of a concentration of flammable materials. Essential electric equipment installed in these areas must be of a design and construction that minimizes the risk of fire.

Emergency Electrical Power

• The emergency electrical power of a mobile offshore drilling unit must provide power for a minimum of 12 hours to the emergency lighting, internal communication system, fire detection and alarm systems and the fire pump. However, if there is a portable communication system in place, the emergency electrical power is not required to feed an internal communications system. The 12-hour requirement can also be provided by dedicated batteries located around the drilling unit instead of the emergency source.

Power Distribution

• Electrical power distribution must be fed to all switchboards and consumers through switch-gears so each section can be isolated for maintenance or during an emergency. All essential systems, such as alarm systems and ventilation, must be connected through a separate circuit to the main switchboard.