Breaker Panels


Making the purchase decision for marine electrical distribution panels —AC or DC—can be tough, not because you’re in danger of selecting a bad product (the ones we looked at for this article were all quite good) but because it’s hard to know how to assess or plan a panel according to what your future needs might be. Off-the-shelf modularity and tech support are keys to a successful purchase. 

Breaker Panels

Each panel maker brings its own philosophy to the market and has managed to carve out a niche. Blue Sea, for example, sells through the discounters and catalog houses and provides good quality, standardized panels in limited configurations at relatively low cost. At the other end of the spectrum you’ll find Bass Products and Ward’s Marine Electric, who deal directly with the customer and make highly customized panels that can include graphics of your own design and any electrical configuration you can describe. The price differential between a simple off-the-shelf panel and a custom panel with identical functions can be a factor of five times or greater.

PanelTronics, Newmar, Marinetics and BEP (Hella) fall somewhere in between Blue Sea and the designer panel companies by offering modular systems in which you (or they) can build a panel to meet your needs from an assortment of assemblies designed to work together seamlessly in both fit and function.

All the electrical distribution panel makers discussed here conform to the recommendations of the American Boat and Yacht Council’s (ABYC) electrical standards and all use UL-rated breakers and conductors. Therefore all of the panels reviewed and all of the panels offered by the these manufacturers can be expected to perform their tasks as advertised, and to do so safely, so long as the installer wires them up correctly.

Panel Basics
Essentially, a marine electrical panel serves to provide and control electrical power to branch circuits on the boat. An AC electrical panel takes shore power or the output of an onboard generator (genset) and provides it to branch circuits that power AC loads such as refrigerators, air conditioners, heaters, and receptacles for TVs, microwaves, battery chargers and other appliances. A DC panel takes power from the batteries or battery charging circuit and provides it to DC branch circuits that feed loads such as navigation lights, cabin lights, and communications and navigation gear.

At the heart of every panel is an assortment of circuit breakers. In both AC and DC panels, the circuit breakers function as switches to control the branch circuits and as current overload detection devices to protect the branch circuits from overheating. And that’s important to remember—circuit breakers are designed to protect the branch circuits (and, therefore, the boat)—not the devices that comprise the loads on those circuits.

The U.S. panel makers purchase most of their breakers from two sources—Carling Switch and AirPax, both strong, high-tech companies that make breakers for aviation, marine, and commercial customers around the world. Magnetic breakers are used in marine applications, and they are fabricated of materials that resist corrosion and hold up under vibration and pounding.

Circuit breakers are rated by voltage, trip amperage, and speed of action. Breakers of a given specification will perform identically regardless of who makes the panels in which they reside. Marine breakers are trip free, meaning that they will trip open on overload, even when the toggle is forcibly held in the ON position.

The fact that the working devices in the competitive panels are identical gives the customer unusually wide latitude in product selection. Rather than focusing on function and safety, you can base your purchase decision on esthetics, fit, and, to some extent, budget.

For this article we asked each of the major panel fabricators to provide samples of their wares. Because we could assume that all the offerings would perform well electrically, we turned our attention to workmanship, component accessibility, installation flexibility, and, perhaps most important, the manufacturer’s ability to provide technical support to the customer. While these assessments were subjective, we were able use them to develop some buying criteria.

Project Planning
Your panel project should begin with some homework, and the best place to start, in our opinion, is on the Blue Sea website. The technical section of this site includes readable, well-illustrated technical articles for the do-it-yourselfer and the marine installer on both AC and DC wiring. The site’s explanations of ABYC standards, including appropriate tables, are especially valuable. While the other panel makers generally do a good job describing their product lines and providing schematics and instructions, Blue Sea is the winner in website information category.

Typically, panel buyers are adding circuits to an existing system, replacing an aging panel, or both. Engineers at all the panel makers’ told us that planning is the most important part of the job, and the one that seldom gets the attention it deserves. You don’t have to be an electrical engineer to plan, but you do have to decide how many branch circuits you need and what you are going to feed with them.

Once you think you know what you want, put the customer service folks to work at each of the vendors. They are a wonderful resource, and their help is free for the asking. If you can tell them how much space you have for the panel (usually less than you want) and the number of circuits you need to control, they’ll come up with solutions from their product lines. Remember, you always want to have some room on your new panel for growth. What follows below is a discussion of the design philosophy of the major panel makers, along with our observations about their products.

Panel Makers
A quiet Connecticut-based company, Bass Products does no advertising and most of its products go to OEM customers such as Hinckley. While Bass has a wide range of “standard” panels, their strong suit is the custom one-off panels they do for yachts. While they’ll make panels in any color you want, they’re known for rich “Bass brown” cover plates. They’ll screen your boat’s logo on the panel and arrange switches and gauges in any configuration you need. Of course, one-off custom panels are quite expensive. If you wish, they try to meet your needs with one of their stock panels. All of their sales are factory-direct.

Blue Sea sells only through the large retailers and its distribution network, and does not do custom work other than populating its panels with an assortment of breakers that match the customer’s specification. Its off-the-shelf panels cover the needs of most recreational sailors. The company takes pride in the amount of technical assistance it offers through its catalog, website, and product sheets.

Blue Sea fabricates its panels from vender-supplied parts and subassemblies. Its workmanship standards are high. The panel we inspected was solidly constructed and the only unit we saw with tin plating on the brass bus bars to reduce their susceptibility to corrosion.

BEP Marine-Hella Inc. and its BEP Marine electrical panel line was the only offshore line we inspected. BEP is a New Zealand company with a wide line of stock panels. If you like a flashy Euro look to your panels, BEP might be the choice. The powder-coated marine-grade aluminum panels are covered with curved plastic facias giving the panel a deep 3D look. BEP is also clever at cramming a lot of breakers into a relatively small space.

Marinetics, a California company, is the granddad of the marine panel industry. It was founded in the late 1960s by folks from the aerospace industry who believed the equipment designed to aviation tolerances would perform well in the marine environment—at least better than what was then offered for use by recreational mariners. The company claims to the first to convince the breaker vendors to harden their products for the marine environments and the first to standardize their panels. While the company still has a dealer network, about half of its sales are generated over the Internet. They provide excellent telephone technical support.

Breaker Panels

The central Marinetics product is a 7.5″ high by 10.5″ high master control panel (AC or DC) with room for eight breakers, a gauge, and a 3″ adaptor port that can accommodate extra circuit breakers, instrumentation, battery selector, inverter/shore panel switch etc. Many of Marinetics sales are made to owners of older boats who are replacing older Marinetics panels with newer, more capable versions.

Newmar is another veteran in the marine electricity business. It designs its panels with the do-it-yourselfer in mind, and provides extra space for making connections —”wiggle room,” as one engineer put it. That isn’t to say Newmar is careless with space. The unit we examined was a compact AC/DC panel that nicely fit a full system into a small package.

Newmar has gone modular in its design and likes to see the final fabrication done at the distributor/dealer level with direct input from the customer. That is to say that the distributor/dealer stocks blank panels, breakers, instruments, labels etc., and works with the customer to assemble a “custom” panel out of the stocked components.

PanelTronics, a Florida company, is arguably the best-known of the makers of marine electrical distribution panels. Their products are sold through the discounters as well as distributors and chandleries. PanelTronics urges customers to seek design help from the company’s technical service reps.

PanelTronics hardware is highly modular. The customer can select a standard panel or simply tell PanelTronics the space available and the types of breakers and instruments needed, and the company will do the rest.

PanelTronics also is especially competent on custom refit panel designs on 30-foot-plus boats, where space is at a premium and the number of branch circuits is large. The PanelTronics printed brochure is terrific. It helps the customer mix and match panel modules.

PanelTronics would be hard to beat in the breaker ID department—the company has over 2,000 polycarbonate labels (for translucent lighting) on stock. So, you’ll be able to find the switches for both your port and starboard jacuzzis.

Ward Marine, like Bass, is strictly custom. Call them with your requirements and they’ll put their technicians to work designing your custom panel. The company can provide engineering, digital engraving, and panel pre-wiring for both the one-off and the hundred-off customer. They tend to work more as a supplier to boatbuilders than to the do-it-yourself crowd.

Should you include a voltmeter or ammeter in your panel? If you can afford the money and space, the answer is yes, for both DC and AC panels. Here’s why. Adding a voltmeter to a DC panel provides you information on battery health. This is especially valuable to the cruising sailor, but powerboaters, too, should be able to determine battery bus voltage and the health of their charging circuits.

An AC voltmeter is important to protect your appliance motors from overheating and possible fire hazard. When AC voltage drops, motors demand higher currents and begin to overheat.

Ammeters—AC and DC— tell you your current load. They’re especially valuable in helping you balance the loads of your appliances, thus heading off circuit-breaker trips.

Reverse polarity indicators and— better yet, reverse polarity trip circuits —are a must for AC power systems. A miswired dockside receptacle could energize the ground or neutral side of your AC circuits and present electrocution risks to you and swimmers around your boat. A system that trips the breaker when it detects reverse polarity is highly desirable.

Some type of lighting for the panel is desirable. Manufacturers are getting away from dimming circuits to improve reliability, and are providing simple LED lights. It’s important to remember that an LED light simply tells you that the branch circuit is activated, not necessarily that the devices attached to the branch are operating.

Enclosures — ABYC recommends that DC and AC panels be located in different places in the boat. That’s simply an attempt to keep you (and technicians) from getting tangled up in lethal AC circuits while working with the relatively safe DC wiring. But, the fact of the matter is that boat owners, designers, and builders like all the electric panels in one place. As a compromise, ABYC insists that if AC and DC are handled on a single panel, the AC components be isolated (usually by a plastic box) so a person working on the DC can’t come in contact with the AC. This is definitely a good idea.

DC wires in most boats are color-coded black for negative and red for positive. AC wires are coded black for hot and white for neutral, the latter at ground potential. Some folks working on DC wires in the proximity of AC circuits have tapped into a black AC conductor thinking they were dealing with a black DC negative. That can have lethal consequences, so be careful out there.

One solution to this problem that you’ll see on newer boats is the use of yellow for DC negative instead of black. See the table on page 4 for other DC wire color coding.

Common Mistakes
The engineers we talked with generally agree that most do-it-yourselfers can handle replacement and expansion of a DC panel with a bit of planning and a few sessions online or on the phone with the panel-maker’s customer service organization. AC installations are best left to professional installers unless you really know what you’re doing.

Breaker Panels

The biggest trap a do-it-yourselfer can fall into is to conclude that the job has been well done based only on the evidence that the load performs. Think about that for a minute. A DC light bulb will work regardless of whether you’ve installed the breakers in the positive or negative wires (positive is correct), but if you get the polarity mixed up throughout the system you can accelerate corrosion of your underwater gear.

If you get the polarity of an AC circuit messed up, the light bulb will work, but you might electrocute yourself when you touch a faucet. So, follow the manufacturers’ instructions to the letter. Pay attention to color coding and be sure to label wires as you go. Keep polarity straight and use polarity testers whenever you are working on AC.

Don’t forget to use GFI receptacles on AC circuits. They may keep you vertical even if you do mess up the polarity.

Another common mistake is to under-wire the job. Branch circuit wires have resistance. If you select a wire too light for the job, the wire will heat and resistance will increase. Voltage (electrical pressure) will be lost in the circuit. This loss is called voltage drop and it should be kept under 3% for critical DC circuits such as those that power navigation and communication equipment. Non-critical systems like cabin lights can tolerate a 10% voltage drop.

All of the panel makers in this article produce good products. Let your pocketbook and your sense of design guide you. If your needs are simple—six or eight branch circuits with or without meters — you can probably drop in at the local marine discounter or chandlery and find what you need on the rack. As your needs get more complex, shop around with your phone and web browser and use the technical support services the panel makers offer so generously. Remember, define your present electrical needs, and then add provisions for additional branch circuits later. (We’ve never heard of anyone who complained of having too many slots available in a breaker panel.)

The last time we looked at panels, in October 1993, we rated PanelTronics and Marinetics tops for do-it-yourselfers both for the wide variety of modules they offered and the versatility of their distribution systems. We have no reason to change our minds today. You can’t go wrong with either vendor.

Blue Sea has entered the market since our earlier evaluation and the company is a welcome addition. If you can use an off-the-shelf system, Blue Sea seems to offer the best pricing because of its mass production/distribution scheme.

Newmar was a solid performer in 1993 and remains in the running today, about midway in the list between price and performance.

BEP’s offerings look good and are beautifully crafted. The company’s products probably are best suited to the OEM market.

If we had unlimited funds and were designing a panel for that very special boat, we’d call Bass and Ward and let them fight over us.


Also With This Article
Click here to view “Color Coordinating.”

Contacts – Bass Products, LLC, 435 Lake Ave., Bristol, CT 06010, 860/585-7923. BEP Marine, Hella, Inc., 201 Kelly Drive, PO Box 2665, Peachtree City, GA 30269; 770/631-7500; Blue Sea Systems, 425 Sequoia Dr.,Bldg. 101, Bellingham, WA 98226, 360/738-8230; Marinetics Corp. 1043 W. Center St. Ste. B6, Costa Mesa CA 92627; 800/762-1414; Newmar, PO Box 1306, Newport Beach, CA 92663, 714/751-0488; PanelTronics, 11960 N.W. 87th Ct, Hialeah Gardens, FL 330108, 305/823-9777; Ward’s Marine Electric, 630 S. W. Flagler Ave. Ft. Lauderdale, FL 33301; 800/297-8240;

Darrell Nicholson, editor of Practical Sailor, grew up boating on Miami’s Biscayne Bay on everything from prams to Morgan ketches. Two years out of Emory University, after a brief stint as a sportswriter, he set out from Miami aboard a 60-year-old wooden William Atkin ketch named Tosca. For 10 years, he and writer-photographer Theresa Gibbons explored the Caribbean, crossed the Pacific, and cruised Southeast Asia aboard Tosca, working along the way as journalists and documenting their adventures for various travel and sailing publications, including Cruising World, Sail, Sailing, Cruising Helmsman, and Sailing World. Upon his return to land life, Darrell became the associate editor, then senior editor at Cruising World magazine, where he worked for five years. Before taking on the editor’s position at Practical Sailor, Darrell was the editor of Offshore magazine, a boating-lifestyle magazine serving the New England area. Darrell has won multiple awards from Boating Writer’s International, including the Monk Farnham award for editorial excellence. He holds a U.S. Coast Guard 100-ton Master license and has worked as a harbor pilot and skippered a variety of commercial charter boats.


  1. Darrell,,
    I just read your article on breaker panels; not a bad article but I feel you missed an important aspect. I do marine electrical work professionally and have for 14 years. I’m a Navy trained electrician/tech. I’m also a really good cabinet maker and have a small shop with machines and tools that I’ve been using for 30 years. I designed and built my own 42′ boat that my wife and I have been living on for the past 14 years.

    Yesterday my job was to install two Blue Sea breaker panels. An AC panel with 3 meters at the top (14 3/4″ x 10″), and a slightly smaller DC panel. I made the mounting frame at my shop, and this is what I found: on three sides of the panel the components stick out beyond the mounting holes. Now, I’ve mounted a lot of electrical stuff and I know that you sometimes need to cut a little extra clearance for a switch or something. But for these panels it was necessary to make 3 separate clearance cutouts at the top (for the meters), 3 separate cutouts at the bottom (for the label light ckt. boards), and a wide cut out on the right for the ckt. breakers. And oh, right, that cut out has to go all the way down, so you can add the three breakers that are not installed yet. And oh, there has to be a little extra cut out for the main breaker that sticks out just a little farther. Darrell, it would be easy to assume that I’m exaggerating how time consuming this was and how accurate the work had to be, but if not done well, half the mounting screws would be dangling in the air. Even so, the material left for the mounting screws is so small it is probably going to break off. The design of those panels is so thoughtless it made me want to vomit.

    I would really like you to actually install one of the panels I’ve described and tell me what you think.

    Sincerely, Winfield Nagle


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