■ Power Supply Requirements

Power Supply Requirements

GMDSS equipment is required to be powered from three sources of supply:

• ship's normal alternators/generators;
• ship's emergency alternator/generator (if fitted); and
• a dedicated radio battery supply.

The batteries are required to have a capacity to power the equipment for 1 hour on ships with an emergency generator or built prior to February 1995, and 6 hours on ships not fitted with an emergency generator or built after February 1995 in order to comply with SOLAS. The batteries must be charged by an automatic charger, which is also required to be powered from the main and emergency generators. Changeover from AC to battery supply must be automatic, and effected in such a way that any data held by the equipment is not corrupted (i.e.: "no break").
During Coast Guard inspections, the batteries must be able to go from 100% discharge to fully charged in no longer than 10 hours in order to pass certification. The charger to must be obtainable at all times during vessel operation and too should be inspected to make sure it functions properly. When the reserve source of energy consists of batteries, the battery capacity must be checked at intervals not exceeding 12 months. If not completed within past 12 months, this must be done during inspection.
Storage batteries provided as a reserve source of energy must be installed in accordance with applicable electrical codes and good engineering practice. They must be protected from adverse weather and physical damage. They must be readily accessible for maintenance and replacement.