How many time have I been confronted to technicians, trying to reboot a piece of equipment and saying “I have tested it at the factory and it worked fine”. Too many, I can tell you.

Even the best audiovisual system technician seems not to be aware that power on a yacht is not the same as power in his house or at the factory. But it is.

Because of the nature of the boat and despite all efforts from shipbuilders, power onboard is less reliable than power ashore. You have three main problems with your energy onboard :
• more frequent loss of power
• unclean peaks of energy
• earth problems and induced current

Loss of power

During the build or refit period, the ship is usually unpowered, unless for tests or measurements. Unexpected shutdowns will  happen very often during this period. You can also loose power when the engineers switch power from the generators to the shore lines, or reverse. More rarely you can have unexpected generator failures onboard, with power shut down for several minutes.

Unexpected shutdowns can have various results on audiovisual and IT systems. Electronics equipment, espacially computer based equipment, are very sensitive to power failure. Sometimes you will need to reboot your system and everything will be back on track, but sometimes you may loose saved settings or have hardware problems (power supply damaged, hard disk crashed…).

I have seen HiFi amplifiers loosing there settings after unexpected power failure, or automation controlers crashing with no other option than unplugging and replugging the power socket to reboot them!

Unclean peaks of energy

A boat is working as a small community, with power loads changing frequently. This induce perturbations over the electrical communications, and “peaks” of energy when demending systems are powered on or off. These peaks of energy are not a problem for strong power supplies, which can easily absorb them. But smaller sensitive power supplies can be disrupted, and induce crashes of the equipment they supply. I have seen this happenned a lot with Set Top Boxes, Automation controlers or Mac Minis: these gears crashed and a hard reboot (I mean by unplugging the power supply) was needed to restart the system. Every time, the technician in charge told me “I don’t understand, it never happened at the factory”. And I trusted him: it never happens at the factory, but it always happens onboard!

Earth problems and induced current

Most ships are now build with steel hull and a lighter aluminium superstructure. When in contact, steel and hull are subject to corrosion and to inducced currents, which can result in potential difference between two zones of the boat. To avoid this, shipbuilders link the two parts with a piece of isolation. Problem is you now have several potential zones onboard that might induce disruption and perturbation to your system.

To avoid, or at least reduce, all these problems, you should always follow these recommandations:
• connect your sensitive equipment to UPS (servers, IP switches, antenna controlers, IPBX…). If possible, connect guests and owner audiovisual equipment to UPS as well.
• connect cat5 or cat6 cables shield only on one end (patch panels but not sockets for instance). This will avoid induced current between the patch panel and distant sockets, especially if cables are pulled through different decks.
• use PoE (Power over Ethernet) devices to connect equipment such as Set Top Boxes, Telephones etc… this will help to clean the peaks on the electrical communication and avoid crashes or “freezing”. It will also give you the possibility to reboot equipment remotely and individually.
• always install a specific circuit breaker for the AV system. And open the breaker when you know there will be power disruption.
• always make sure interior designers will leave good access (front and rear) to the system gears. If not, don’t even install the system, as you will not be able to operate it properly!
• simplify your system: the more gears you have, the less reliable your system will be. Instead, make sure you are using all the features of each component of the system : THIS is your added value!

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Tech tips by bruno