Articles about Catamaran Electrical Systems

You're heading offshore and have come to realize that almost every important system on your boat depends on a steady supply of electricity. You find yourself asking, "will I have enough electrical power on board, especially when I really need it?" Good question. To answer it you first need to take a close look at your projected daily electrical load and see how that compares with the amount of electrical power you can reliably provide on a daily basis. Most multihull sailors preparing for blue water cruising these days find their electrical power situation is unbalanced-too much load for t.....

Multihull sailors attempting to make and manage their own electrical power supply must have some way of storing electrical power for later use. With renewable power sources such as solar, wind and water chargers it's essential to take advantage of favorable charging conditions while they last. And with engine-driven charging sources it's best to be able to charge at the highest rate possible while the engine is running, then tap your stored electricity until it's time to generate again. Although many energy storage mediums have been proposed over the years, lead-acid batteries remain the mo.....

Multihull sailors need adequate charging sources to routinely replenish the battery power they use, and the proper controls for those charging sources to protect and extend the life of their battery banks on board. In this two-part column we'll review the charging controls on the market and their operation. Each charging source you install on your boat must have some sort of charging control to limit or shut off the current once the batteries are full. Alternators and other charging sources are designed strictly to provide power, a given amount for the conditions they operate.....

Part I Understanding DC CircuitsThose sailor's building a new multihull or renovating an existing one are eventually faced with the task of wiring from scratch or rewiring the DC side of the boat's electrical system. This process can be less daunting if you understand what DC circuits are all about, and spend time planning for a proper installation. Think of a circuit as a path that, if followed completely, leads back to the starting place. In this column we are concerned with electrical circuits that provide a reliable path for direct current (DC) on a sailing multihull. While t.....

Some Practical ConsiderationsThere has been growing interest in electric propulsion for sailboats. The lure of clean, silent electric motors capable of replacing the diesel auxiliary inboard(s) seems to be especially strong for multihull sailors, but then they have always been able to think outside the box and are, in general, more open to new concepts than their single-hull counterparts. Despite their forward thinking and willingness to embrace new technologies, however, they ultimately want equipment and systems that work well. And they are, in general, quite willing to spend some extra.....

An electrical power system on a boat is comprised of various electrical circuits. A circuit can be thought of as a path that if followed completely leads back to the starting place. An electrical circuit refers to a complete path for electrical current flowing through wires. An electrical circuit is formed by connecting a voltage source such as a battery bank or AC power source to one or more electrical loads (appliances that use electricity) by means of a conductor, typically copper wire. In a DC battery circuit battery voltage pushes electrical current through various electrical loads w.....

If you have a large AC electrical load and spend time away from dockside shorepower, you'll probably need to look beyond the capabilities of DC-to-AC inverters and start investigating gen-sets. Even if a properly sized inverter is capable of handling your load, the charging system needed to replace battery drain may well be impractical. A good example of an AC load too large for most inverter installations is air conditioning. The instantaneous AC current draw from air conditioning ranges from fairly modest to high, depending on the BTU rating of the unit. But it's not the curr.....

Beyond the glamor of high-output alternators, solar and wind chargers, battery banks and system monitors are the hidden essentials of any respectable marine electrical power system, those heavy-duty DC circuit components that provide safe, efficient wire termination points and switching ability. Long ignored by boat owners, boat manufacturers and electrical system suppliers, these important pieces of gear are now standard equipment on most high quality marine installations.I use the term "heavy duty" to describe this class of electrical devices, not to imply that they all have the same degree.....

This article is a continuation of Marine Electrical Panels from the Nov/Dec 2001 issue.  In this issue we discuss some of the other panel components, and how to make an intelligent choice of electrical panel for your multihull.  Circuit ProtectionAlmost all electrical panels on the market now use circuit breakers as the preferred circuit protection device.  They are more convenient to use, and they provide switching and circuit protection in on neat package.  But fuses are totally absent from the panel scene.  You can still find electrical panels with th.....

Most multihull sailors are aware that photovoltaic (PV) solar panels can be a great way to charge batteries on a catamaran or trimaran. These technological marvels are able to convert light into electricity with no noise or moving parts, and they can do it with greater efficiency (over 16%) than standard incandescent light bulbs can change electricity into light (10% efficient). The advantages of solar panels are numerous and a multihull provides an almost ideal platform for solar power, but even multihull sailors face the sometimes daunting task of finding suitable places to mount.....

One of the best ways to make sure there's always enough battery power on board is to reduce your electrical demand where possible. This doesn't mean you have to give up conveniences or safety gear you've come to enjoy and rely on. Most multihull sailors can reduce their electrical load significantly simply by choosing efficient appliances and operating them wisely. Reducing electricity use before selecting charging gear is similar to insulating a house before selecting a heating system. Reducing demand can get you most of the way toward self-sufficiency and the ability to use.....

The Shorepower Supply When laying out our electrical power system we often neglect the AC side things. AC here refers not to air conditioning, which many modern multihulls choose to include in their list of appliances, but to alternating current, the same type of power found in a house or dockside. In this series of articles we'll review the various options for providing AC power and the system components needed to make your system functional and safe.Let's begin with the Shorepower supply, since almost most cruising multihulls have provisions for hooking up to dockside power. The simplest.....

Sailors in the North American market have become accustomed to the concept of having an inverter (a unit that takes DC battery power and "inverts" it into household AC power) and an AC-to-DC battery charger in one neat package.  At first glance these combination ("combi") units seem to have several main advantages over having a stand alone inverter and charger.  With a combination inverter-charger there is only one piece of equipment to purchase and install, and the cost is typically lower than for separate stand alone units.  Combi units also have an internal trans.....

These days the electrical power system on board a cruising multihull has to be rugged, reliable and, most importantly, easy for the crew to understand and operate. How hard is it to find a system that meets all these criteria? Easier than you might think, especially if you take the right approach to system planning. As a first step I recommend you assume the role of system manager of your own private utility company, for that adequately describes the situation you'll be in whenever you leave the dock. There are rewards and responsibilities that come with the territory. Your best chance of.....