Advantages of Distributed Power Systems

‘Smart’ Circuit BreakersThe remotely operated switches in a distributed power system use electronic circuit breakers (ECBs). Current practice is to cluster several electronic circuit breakers in what I will call a Power Distribution Module, or PDM. The PDM is connected to the boat’s main two-wire bus, and then the individual circuits in one area of the boat (such as the lighting circuits
Author:
Updated:
Original:

‘Smart’ Circuit Breakers

The remotely operated switches in a distributed power system use electronic circuit breakers (ECBs). Current practice is to cluster several electronic circuit breakers in what I will call a Power Distribution Module, or PDM. The PDM is connected to the boat’s main two-wire bus, and then the individual circuits in one area of the boat (such as the lighting circuits in a cabin) are fed from the electronic circuit breakers in the PDM. A data cable connects the PDM to the boat’s control panels, and is used to trigger the electronic circuit breakers.

Whereas a traditional switch or circuit breaker has a given current (amperage) rating, an electronic circuit breaker is programmable. A boat builder can install a series of identical PDM units throughout the boat (so only one model has to be stocked by the boat builder, and kept as a spare by the boat owner), wire all the circuits, and then hook up a laptop when the job is finished and program the individual electronic circuit breakers to whatever trip characteristics are desired. This greatly simplifies the installation. If the equipment at the end of any circuit is subsequently modified, the electronic circuit breaker can be re-programmed. Electronic circuit breakers used on lighting circuits can also function as dimmers.

How a power distribution module works

Electrical circuit breakers control individual appliances, such as light or instruments, and are clustered together in a Power Distribution Module (PDM). Microprocessors in the PDM allow a great deal of control over each appliance.

calder1

1. The blue and brown terminals are the positive and negative feeds to six individual circuits; check the thumb for a size reference

2. The heavy black and red cables (see the image below) are the positive and negative connections to the boat’s main power junctions

3. The white buttons are the manual override controls for the electronic circuit breakers

4. The black squares in the middle are the electronic circuit breakers

5. This microprocessor runs the PDM and relays data

6. The entire unit is “potted” in resin to keep moisture out. With the cover removed, here's how the unit looks —

calder2

Related

pic00

Installing a Helm Pod

Our 1987 Pearson project boat came with an elderly but functioning Raymarine chartplotter, located belowdecks at the nav station. Since I usually sail solo or doublehanded, it was of little use down there—it needed to be near the helm. When I decided to update the plotter along ...read more

Panamerican

Pan American Game Success

Team USA’s young sailors went to the quadrennial Pan-American Games in Lima, Peru this summer with high hopes, and returned with a good haul of medals—two Golds, three Silvers, and two Bronze. Gold medals went to Ernesto Rodriguez and Hallie Schiffman (Mixed Snipe) and Riley ...read more

190916-AC75

U.S. Team Launches First America’s Cup Boat

Fast forward to around 2:25 to see the boat in action. First day out and already doing full-foiling gybes: not too shabby! Hard on the heels of the unveiling of New Zealand’s first AC75, the New York Yacht Club’s American Magic team has now launched its first America’s Cup ...read more

GGTobCaysHorseshoeColors

Picking a Charter Destination

Picking a destination should reflect the interests of your group, says People often ask about my favorite charter destination, and invariably, I sidestep the question with one of my own: “Well, what do you want to do on your vacation?” Most often I hear an incredulous, “Why, ...read more

sinking

Waterlines: Chasing Leaks on Boats

Chasing leaks on boats is a time-honored obsession. Rule number one in all galaxies of the nautical universe through all of nautical history has always been the same: keep the water on the outside. When water somehow finds its way inside and you don’t know where it’s coming ...read more

BestBoatNominees2020-Promo

Best Boats Nominees 2020

Bring on the monohulls! In a world increasingly given over to multihull sailing, SAIL magazine’s “Best Boats” class of 2020 brings with it a strong new group of keelboats, including everything from luxury cruisers nipping at the heels of their mega-yacht brethren to a number of ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com Relieve the load  One of the ancient arts of the sailor is setting up a “stopper” to relieve a loaded rope without letting anything go. The classic use for a stopper is to take the weight off the genoa ...read more

05

Ask Sail: Water Getting into Coax

Q: While inspecting behind the nav station for my spring cleaning, I discovered water behind my chartplotter and VHF radio stack. Freshwater to boot! Do electronics leak? I didn’t think so. — Everette Gracy, Norton Shores, MI Gordan West Replies  Last winter your region was ...read more