In our June/July issue, we looked at optional bonding systems, which are typically associated with corrosion prevention. Closely related to bonding systems are mandatory alternating current safety grounds. If your vessel has an AC power system—supplied by shore power, a genset or inverter—then the safety ground is critically important.  

The terms “ground,” “bond” and, to some extent, “DC negative” are often used interchangeably. While they are related, they each have a different mission.

In marine electrical systems, a ­grounded conductor is always common with ground. This would apply to the ­neutral or white wire in a 120-volt, alternating current (VAC) system. The conductor must always be common with the ground at its source, which includes a dockside utility transformer, onboard ­generator or inverter, or onboard transformer. The conductor can also include objects that are permanently connected to the grounding system, thereby making them grounded at all times.

A grounding conductor provides a path to a power source only in the event of a fault. It does not carry current or amperage under normal conditions. Grounding conductors are typically green, and they are, or should be, part of every onboard alternating current electrical system. All ungrounded, or “hot,” AC conductors must be run with a grounding conductor alongside them in the same sheath or bundle.

Contrary to popular belief, electricity does not seek ground. In fact, it seeks to return to its source, which often is grounded. In the case of an onboard AC system, this means that a fault will attempt to return to a dockside utility transformer, where the ground and neutral are bonded. If the boat is away from the dock, the electricity will seek to return to one of the other aforementioned sources: the generator or inverter.  

The most common type of AC ­electrical fault involves an energized, hot or ungrounded conductor coming into contact with a metallic object. This object could include an electrical enclosure such as an inverter chassis; the outer portion of a galley appliance, such as a refrigerator, toaster or coffee maker; or engine blocks and tanks. If these objects are not grounded, then they will become energized by the fault.

In a scenario I experienced personally, an energized conductor chafed against a fastener securing a sail track. The vessel was hauled. I leaned an aluminum ladder against the rail on a rainy day. When the ladder made contact with the rail, a return path was completed via the utility company’s grounded transformer, and via my hands and feet. I received an electric shock.

Probably thanks to my heavy-soled boots, this shock was uncomfortable but not life-threatening. If I’d been barefoot, you likely would not be reading this column now.

The reason this near-catastrophic scenario occurred was because the sail track was not grounded. Here’s where bonding and AC safety grounds intersect. These two systems should be common for this very reason. Had the sail track been bonded when the wire chafed through to it, the fault current would have been able to return to its source, thereby tripping a circuit breaker.  

Some builders, in an attempt to mitigate corrosion, opt to isolate bonding and AC safety ground systems. The scenario I experienced is precisely why that approach is undesirable. Ultimately, for the greatest degree of safety, all grounding, bonding, DC negative and lightning-protection systems should be common; electrocution protection should trump real or perceived corrosion mitigation.

Steve D’Antonio offers services for boat owners and buyers through Steve D’Antonio Marine Consulting.

The post Monthly Maintenance: Proper AC Safety Grounds Can Prevent Electric Shock appeared first on Cruising World.

For years, I’ve been touting the advantages of 24-volt DC systems on boats. Higher voltage equates to lower current and less electrical resistive loss in an onboard electrical system. Boatbuilders say that the primary reason they have not adopted 24 or higher voltages is a lack of available components. Well, rest assured, that is rapidly changing.

As with many marine systems, much of what we see on boats gets its start in much larger industry sectors, primarily automotive and recreational vehicles. In this case, the movement to all-electric or hybrid-electric propulsion systems in cars and light trucks is a primary driving force. Consumer demand for onboard equipment with functionality similar to a new Audi or Tesla plays a part as well. So, with that said, let’s look at where we are today, and at how to think about upgrades on an older boat or accessory choices on a new one. 

Electrical Fundamentals

One big worry about cruising boats and their wiring has to do with voltage drop, where battery-level voltage doesn’t actually reach the appliance the battery is supplying. Boats will often have longer wire runs than automotive applications. All wire has some inherent electrical resistance that will lower the voltage at the appliance. This is acceptable, to a point. 

The American Boat and Yacht Council and the International Standards Organization identify two levels of acceptable voltage drop for battery-powered direct current (DC) systems: 3 percent and 10 percent. The bigger the wire diameter, the less inherent resistance it will have. As for voltage, higher voltages mean that lower amperage is required to achieve the same level of power (watts). 

The math here is simple. Wattage (power) is equal to volts times amps. (I’m talking about DC applications here.) Things like power factor come into play with alternating current (AC) equipment. So, by using higher voltages, designers can generate higher power to run more electrically demanding DC equipment. And there is no question that modern cruising boats have considerably more gear on board than boats built 10 or 20 years ago.

Equipment Changes

Cruising boats have been working with 12 volts for decades. When I was cruising back in the late 1970s and ’80s, our boat was equipped with 12-volt battery power to run our VHF radio, loran-C, depth and speed gauges, an AM/FM stereo, and ­incandescent cabin and navigation lighting. 

We didn’t have shore power because we had no need for it. The alternator on the engine recharged the batteries. We read at night using oil lamps that essentially eliminated the need for electric cabin lights. We cooked with LPG. We used sun showers to heat our water, and our head was completely manual. We had manually operated and electric bilge pumps. Our wind instruments consisted of telltales in the rigging, a masthead indicator and a handheld velocity meter. Life was good and, by today’s standards, quite simple. Today, you’d be hard-pressed to buy a new boat without air conditioning, extensive refrigeration, a water heater, and an array of electronic equipment including radar, autopilot, television and LED lighting. 

Additionally, unlike my old cruiser with a fully mechanical diesel fuel-injection system, a modern cruiser is likely to have a fully electronic fuel-injection system, again requiring more electrical power. 

Oh, and let’s not forget the bow thruster, anchor windlass and electric winches for sailhandling. 

The bottom line is that electrical power demands on a new boat have continued to increase. Even though additions such as LED lighting draw a minuscule amount of current (amperes) compared with incandescent options, the sheer amount of equipment that modern boat buyers expect to have on board is considerable. 

48 Volts and New ­Technology

In the automotive and marine markets, there is still a vast amount of 12-volt electrical equipment in use and available. Interestingly, we seem to be jumping past the 24-volt options in many cases and going right into the 48-volt world. 

Generally speaking, 24-volt systems have been used for large diesel-engine starter motors and some high-current gear, such as bow thrusters and anchor windlasses, but have never caught on in a wholesale fashion, at least here in the US. Historically, some American builders embraced 32-volt systems, but those systems have largely been replaced as boats aged and equipment became nearly impossible to find. Today, you are likely to see a boat with a mix of 12-, 24- and 48-volt gear installed. 

The advantages to higher voltage include a significant weight savings in the wiring. Heavy-gauge wire cabling is just that: heavy. It’s also quite expensive. One cruising catamaran builder told me that by switching to a primarily 24-volt system, he was able to save approximately 1,000 pounds just in wire. 

Now that we are beginning to see lithium-battery technology taking over in the marine world, additional and rather significant weight savings are also coming into play. While 48-volt lithium-battery systems are now mainstream, 48-volt alternators are also becoming readily available. Lithium batteries weigh approximately one-third less than their lead-acid counterparts, and typically offer about 50 percent more usable energy. Companies such as Vetus, Kenyon, Victron and Mastervolt, as well as the RV and automotive sectors, are introducing 48-volt equipment at a noticeably increased rate. 

Even with this increase in equipment production, it’s still going to be a while ­before 12-volt gear is long forgotten. So, the question becomes how to mix and match voltages required on a new boat. 

Enter the DC-to-DC voltage converter. With these electronic marvels, we can step down voltages electronically from 48 to 12 or 24 volts, or step them up from 12 to 24 or 48 volts. Most modern cruising boats have at least one, and often several, of these converters. Expect to see more of these mixed systems as equipment manufacturers evolve and old inventory gets used up. 

Summing It All Up

I see no letup in the development of hybrid and fully electric power systems in the automotive world, and I believe that this reality will continue the drive toward higher DC voltage systems across the board. 

Marine industry standards ­development is currently underway to address things such as wire sizing and safe lithium-­battery installations, as well as electric propulsion for recreational boats. This fact is a true indicator that these changes to boats are imminent. Standards-writing bodies can’t afford to invest time without a clear signal of need from the industry. 

Consumer demand will continue to be a driver too, and I don’t see much interest in going back to sun showers and oil lamps on board.  

The post Making Onboard Adjustments for a Mix of 12, 24 and 48 Volts appeared first on Cruising World.

Recently I met with a client to review and critique his vessel’s systems. One item I saw related to the bonding or grounding system. These systems serve similar purposes: to carry stray, galvanic or fault current back to its source.

Let me clarify two related matters. First, electricity does not “seek ground” as so many dockside sages insist. No, whether from a battery or shore power, it seeks to return to its source. One example of the return-to-source concept is all-too-often tragic; it relates to electric-shock drowning, or in-water electrocution. When AC current, which originates from shore power, “leaks” into the water in which the vessel floats, it attempts to return to its origin, which in most cases is a transformer located on the dock or in the marina parking lot. Once power passes through a transformer, that transformer becomes a power source. So if a shore-power transformer is installed aboard a vessel, fault current will seek to return to that transformer—rather than through the water—and on to the one supplying the marina, making it a safer option.

RELATED: The Dos and Don’ts of Boat Wiring

Second, while the terms are frequently and understandably used interchangeably, “bonding” is often used in conjunction with underwater metals and corrosion prevention, while “grounding” often refers to the connection of equipment chassis and hardware to the DC-negative terminal. The two systems are, however, almost always connected (along with the AC safety and lightning ground systems), so for the purposes of this discussion, they are one in the same.

In the case of my client’s boat, I noticed a 14-gauge wire connected to the engine block. It appeared rather new, and when I asked about it, the owner confirmed that an electrician had installed it in the not-too-distant past. A poor block ground can cause oil-pressure and coolant-temperature-gauge issues, which may have been the impetus for adding it. While this “fix” may have solved one problem, it created a fire risk.

Another electrical myth is “electricity takes the path of least resistance.” In fact, electricity takes all paths, with the current flow being proportionate to the resistance. Thus, more current flows through lower-resistance, larger-wire paths; when both are present, larger wires carry more current than smaller wires. But what happens if the larger wire breaks, or is inadvertently disconnected, or the connection loosens or corrodes? In that case, a small-gauge wire connected to an engine block will be called upon to carry high current, such as from a starter or alternator.

A few years ago, I was inspecting the engine room on a 60-footer. A mechanic had recently replaced the batteries, then started the engine to test his work. However, when removing the old batteries, he’d dropped one cable behind a battery box and then failed to reconnect it when installing the new batteries. When he turned the key, instead of flowing through a cigar-size 2/0 cable, the starter current instead took an alternate path through a 12-gauge bonding wire connected to the engine block. A few feet away, I recall feeling the heat on my face as it almost instantly glowed white-hot, and the insulation melted and then burned away. Fortunately, the wire melted before anything caught fire.

It doesn’t take a miss-wire scenario for an event like this to occur. If the starter’s or alternator’s positive cable chafes against the engine block (ABYC standards prohibit starter positive cables from touching the block in any way), current will attempt to return to the battery via all paths, including small bonding wires.

The simple moral? Every grounding/bonding wire connected to the block of an engine or generator, or to any other piece of DC equipment, must be capable of carrying full starting or fault/short-­circuit current, which means it can be no less than one size smaller than the largest DC-positive cable. Furthermore, bonding wires should not be connected to current-carrying parts. If the chassis of the block, thruster, etc., is common with the DC-negative, then it should not be bonded. Engine blocks and gensets that utilize isolated ground starters and alternators may, on the other hand, be bonded.

Steve D’Antonio offers services for boat owners and buyers through Steve D’Antonio Marine Consulting.

The post Sailboat Grounding Systems appeared first on Cruising World.

If you’ve been attending boat shows for the past 10 or 20 years like I have, you have surely noticed significant design evolutions from the major sailboat builders. Wide beam carried all the way aft to a plumb transom—which often articulates into a sweet boarding deck, sometimes even opening up a garage for a tender and motor—are becoming the norm. Dual helms and twin rudders are commonplace, and you’d be hard-pressed to find a boat without installed air conditioning and sophisticated refrigeration systems. Boats 30 feet and longer often have a bow thruster as an option, and shore power is standard equipment.

Recently I had the opportunity to turn on the not-so-way-back machine and take a trip to the 1980s to remind me what life on board back then was about. Let me share with you some of my observations and what I would consider changing if I were to buy such a boat.

The sample boat here is a Germán Frers-designed 1983 Beneteau First 42, offered for sale by Dave McKenny at Brewer Yacht Sales in Rhode Island. It is a one-owner boat that was repowered about 10 years ago, and its hull and deck have been repainted. The interior woodwork is the classic dark bright finish of the era and is in excellent condition. More common to that time, the boat has two proper sea berths port and starboard, amidships above and behind the standard saloon settees. And the upholstery has been updated.

The onboard electrical and electronic systems, however, are mostly original, with the exception of a fairly recent autopilot, a 1,000-watt DC-to-AC electrical inverter and an Isotherm seawater-cooled DC refrigeration/freezer upgrade for the original icebox in the galley. The boat has no shore-power system installed, which amazingly was not that uncommon back then. There is no bow thruster or electric windlass; winches are all sized properly but fully manual. So the question is, what would I do to bring this boat’s almost-40-year-old electrical/electronic systems into the new century?

Charge It

Step one would be to analyze the existing source of electrical power. Currently the boat is equipped with a pair of Group 31 flooded-cell lead-acid batteries. They get recharged by a stock 65-amp alternator controlled by an ancient Balmar voltage regulator. This battery bank has an amp-hour capacity of about 200 amps, but unfortunately flooded lead-acid batteries like these suffer from cycle-life reduction if they get continually discharged below about 50 percent of their capacity. In effect, this boat currently has about 100 amp-hours of power available for running accessories.

In my dream redo, this would not be adequate, and I consider it marginal even as the boat is equipped now without a bit of engine run time to keep those batteries charged.

For me, one of the first upgrades would be to replace these batteries with a pair of group 31 absorbed glass-mat batteries. AGMs have considerably higher recharge-acceptance rates compared with flooded-cell batteries, and can be discharged up to 80 percent of capacity, meaning that engine run times will be at a more acceptable level when away from the dock, at least in terms of electrical-power generation. Upgrading the alternator and voltage regulator to a 100-amp Balmar set would also be on my list for this boat to minimize engine run time.

My intention is to add quite a bit more electrical equipment to this boat, and I prefer not to run things such as alternators near their maximum capacity for extended periods of time. Limiting the amount of full output extends their potential service life considerably.

Plug and Play

AC power on board today is almost a must for boats that are going to be berthed at a dock. Yes, global warming is real, and sleeping on board without air conditioning at this point in my life just isn’t happening.

I’ve lost my enthusiasm for cold showers as well. In the old days, we used sun showers hanging from the boom in the cockpit and got by just fine, but that was then and this is now. The luxury of hot water on demand is not too much to ask in this day and age. So besides adding air conditioning to this boat, we are going to need to add a water heater and appropriate plumbing to deliver hot water to the galley and two heads.

The current refrigeration system, an Isotherm ASU unit, is only a 12-volt, and I would think about swapping that out for a 12-volt DC/120-volt AC unit. Or, as a money saving measure, I might just leave the 12-volt unit in place because I’m going to be installing a proper battery charger to keep my new AGM batteries charged up anyhow. We’ll let the charger replenish the power used by the Isotherm unit.

The bottom line here is that the boat is going to get shore power installed for the first time. The question becomes whether a 30-amp system or a 50-amp system will be needed. Determining that requires performing a load analysis. Here’s how I would go about doing it.

First we have to determine how many Btu we’re going to need to cool the boat. A visit to marinaire.com will connect you with a calculator that will provide the Btu per hour needed to air-condition the boat in either moderate or tropical environments. I chose moderate for this boat because based on MarineAire’s world map, only South Florida is in its tropical zone, and the plan for this boat is to stay in the mid-Atlantic to Northern states the majority of the time.

Based on the calculator results, I still came out needing one of the company’s largest units, which can produce 16,000 Btu of AC and 17,000 Btu of heat when needed. This unit draws just under 11 amps of AC power at 110 volts.

My new water heater will draw 13 amps, and I’ll need another 8 amps for my P-12 Blue Sea 40-amp battery charger.

With an air conditioner, water heater and battery charger plugged in and running, we’re looking at just over 30 amps of AC power needed. That figure does not include any provision for a microwave oven, coffee maker, hair dryer or any other small AC appliance while at the dock.

Knowing this opens up two options for shore power: either a 50-amp service or possibly two 30-amp setups. The potential problem here is the marina itself; many don’t offer a 50-amp option at the dockside pedestal. There are myriad adapters available that would allow you to tap into multiple outlets to get to 50 amps, but remember: You don’t want to pull more than 30 amps from a 30-amp service.

One additional shore-power consideration on this boat is the 1,000-watt DC-to-AC inverter that has been installed. This was possibly done to facilitate running a laptop at some point, or maybe an electric shaver or small hair dryer. It is located in the aft head compartment, so I’m going with the shaver idea.

My inclination would be to relocate the inverter behind a panel in the navigation-station area, probably under the settee at the nav station, and resize it to a 2,000-watt unit. I would add a dedicated battery to supply DC power to the inverter and make sure the battery is connected to my Blue Sea charger. Since I am going to be running only intermittent loads from the inverter, a group 27 AGM will get the job done.

Note that I am not considering a generator for this major upgrade. Space is tight, and I don’t want to carry the extra weight. This is a performance cruiser, and I want it to stay that way. Besides, my plan is to stay mostly in slips when traveling, and so I’ll have access to shore power when I need it.

A Wednesday-night race series is in the plan as well, so I won’t be adding a bow thruster, anchor windlass or electric winches. For the occasional overnight away from the dock, I will still have the power I need to microwave some popcorn and run a laptop to check a weather forecast or watch a downloaded Netflix movie.

Side note: I have no plans to add solar panels or a wind generator either. I love the lines of this boat just the way Frers designed it.

In Control

Based on the proposed changes to the electrical system, a new AC/DC combined panel is in order. The boat is currently equipped with 12 DC circuits and no AC circuits. We will also need to modify the battery-switching system, so that will allow the three new batteries, combined, to be separated.

For the panels, Blue Sea, Paneltronics and Bass Products are all possibilities. I just need to take some measurements to see what will fit where the existing panel is mounted. The design will also depend on whether I decide to go with a single 50-amp shore-power service or two 30-amp services.

In either case, rather than having two cigar-lighter-style outlets, we’ll swap those out for a pair of Blue Sea USB plug adapters, which are more relevant in today’s world.

Instruments and Toys

With the exception of the autopilot, the original onboard electronics need to be replaced. A pair of multifunction displays are in order here, with one mounted at the traditional nav station down below and another in a pod at the helm. An updated VHF with digital selective calling and possibly integrated AIS will also be needed. And since trips north to Maine from Annapolis will be part of the plan, we’ll add radar. Air, wind and speed instruments will also be integrated via NMEA 2000. Since coastal cruising is going to be the primary use for this boat, satellite communications will not be part of the permanent upgrades.

I’m not a television person, so a boat with a flat-screen TV that rises up from behind a settee and interfaces with the chart plotter means nothing more to me than just one more thing that can break and need repair. I do have an iPad loaded with my favorite tunes though, so some speakers and a small AM/FM stereo set that connects to my iPhone or iPad via Bluetooth will augment the good company I plan to have on board for entertainment.

Dollars and Sense

The used-boat market has a huge inventory these days, and there a lot of really great boats available for any price range—and at considerable savings compared with the cost of a new boat.

This Beneteau First 42 that I have my eye on has an asking price of $59,900. Although there is no direct comparison for the 2020 model year from Beneteau, a similar boat in this size range would cost over $200,000. That’s at least a $140,000 differential.

That can buy a lot of upgrades!

The proposals I suggest here will not be inexpensive, but when compared with the cost of a new boat with similar equipment (much of it optional), you can come out tens of thousands of dollars ahead with careful selection of the right used boat. I think the biggest part of any decision here is to be totally honest with yourself about your genuine needs versus your dreams and desires.

Ed Sherman writes frequently on a range of technical topics for CW. He is a longtime Boat of the Year judge, and recently retired as vice president of the American Boat & Yacht Council.

The post Sailboat Electrical System Upgrades appeared first on Cruising World.

It’s time: Your engine barely turns over to start and your cabin lights are getting dimmer faster, both signs that you might have a shortage of available electrical power. That means you’ll either need to replace your existing batteries or figure out how to improve on your current power supply.

What are your options? A trip to the West Marine website is telling. Currently, it lists 56 different battery options. Of those, 17 are flooded-lead acid; 36 use absorbed glass mat (AGM) technology; there are seven gel-cell batteries; and three lithium choices that are proprietary and dedicated replacements for Torqeedo products. If you have any faith in market-driven inventory control, then the choice is clear: AGM is the way to go today. If the buyers at West Marine select twice as many AGM battery options as compared with traditional flooded cell devices, that speaks to me. Further, the only lithium choices West Marine currently offers are dedicated to a specific product that has always used high-quality lithium technology as its power source.

So let’s look at where we are with each of these technology choices and what you need to consider if you are thinking about shifting from one to another.

It’s a System

To really dig into this whole matter and get it right today requires thinking about batteries as part of an onboard system. This system includes the batteries, an alternator, voltage regulator, a shore-power-driven battery charger, maybe an onboard AC generator and, for the cruising sailor, water, wind and/or solar chargers. The system also includes both the AC and DC wiring needed to properly interconnect all the other equipment. The prudent sailor will probably want to add a battery-monitoring system as well to act as a fuel gauge for the electrical power supply.

Let’s begin this analysis by answering the question: What are we trying to achieve?

Value for your battery dollar is the most likely answer. Historically, I’ve always used cost-per-amp-hour of power as my guide. This is determined by knowing the average cycle life and using the battery’s amp-hour rating and either a 50 percent or 80 percent discharge, depending on the recommended levels of discharge per cycle. Next, multiply the amp hours by the number of cycles, and then divide the battery price by the number of amps derived earlier, and you’ll have a value for the cost per amp hour. The problem with this approach is that it relies heavily on battery-cycle life, which is controlled in large part by all the elements in the system that I described above.

When I wrote the first edition of my Power Boater’s Guide to Electricity back in 2000, the numbers looked like this:

• Flooded-cell lead-acid: 0.00065 cents per amp hour
• Gel cell: 0.0027 cents per amp hour
• AGM: 0.0013 cents per amp hour

Keep in mind that these figures were based on manufacturers’ estimated cycle life for their respective products, so there may have been some “optimism” in their advertised cycle-life expectations. Also, because we really didn’t know any better at the time, I assumed an average 50 percent discharge level for each cycle for all three technologies; deeper discharge levels hadn’t been recommended.

Today’s numbers look a bit different because they take into account current pricing and 80 percent discharge levels for both gel-cell and AGM technologies. Here’s how today’s cost-per-amp-hour values add up:

• Flooded-cell lead acid: 0.015 cents per amp hour
• Gel cell: 0.010 cents per amp hour
• AGM: 0.016 cents per amp hour

Clearly, prices have changed for all three types of batteries, but it appears that large disparities between them have been reduced considerably. (Cycle-life data for this analysis came from both West Marine and civicsolar.com.) Add to these prices the cost of the equipment needed to properly charge these batteries to ensure maximum cycle life, and I think you’ll find a significant jump in the gel-cell cost per amp hour. Read on, and I’ll explain.

Gel-Cell Potential

Battery technology has improved considerably in the past 20 years, in part because of the interest in electric cars and trucks, so a change in the cost-per-amp-hour numbers is to be expected. Even back when I originally looked at them, I remember talking with the folks at East Penn manufacturing, makers of the popular Deka brand of marine batteries. They told me their warranty data indicated that their gel-cell line of batteries would outcycle flooded-cell or AGM technology in deep-cycle applications. Their position remains the same today.

But there’s more to consider than just the number of cycles. Because of their construction, gel-cell batteries are the most finicky about their recharge regimen, and in my own experience, improper charging is what kills them—and it can happen rather quickly, typically in one sailing season or less. So, if you want to go the gel-cell route, be prepared to upgrade your engine’s alternator to one with a remote, programmable voltage regulator. Also, make sure that your shore-power charger, if you have one, has a gel-cell setting or adjustable voltage levels for its various phases of charging. Any solar- or wind-charging units must be run through a charge controller that can handle the lower voltages required by the gel batteries.

Here’s why: Depending on the manufacturer requirements, gel batteries should never be subjected to a recharge voltage greater than 14.7 volts, and some vendors state no more than 14.1 volts for any sustained period. Therein lies the problem: Internal voltage regulators on engine-driven alternators are of the constant-rate variety and typically produce in excess of 15 volts. So, in a nutshell, whenever your engine is running, you are rapidly destroying a gel-cell battery unless a programmable regulator has been installed in the system and set appropriately.

Now, don’t get me wrong—gel-cell batteries have some real advantages. They are sealed-valve-regulated, meaning they will vent, but only under overcharging if excess pressure builds up. They require essentially zero maintenance, and have excellent deep-cycling capability and a very low self-discharge rate (3 percent per month). But again, they must be connected to a properly calibrated charging source. If your boat is already equipped with gear that can be adjusted to meet the need, this could be a great choice. Otherwise, some detailed cost analysis is needed, and you might find that your cost-per-amp-hour is too high after all the upgrades are factored in.

A Look at AGM

AGM batteries have come a long way over the past two decades as well. Spiral cells and thin plate pure lead (TPPL) are two of several examples of how battery-makers have worked to optimize the amount of power they can squeeze into a battery of a given size. Like their gel-cell brothers, AGM batteries are sealed-valve-regulated, low maintenance, and can be discharged to extreme levels—80 percent of their capacity versus 50 percent for conventional flooded-cell batteries. AGMs also have a significantly higher recharge acceptance rate—35 to 45 percent of capacity in amperes versus 25 to 30 percent for traditional flooded-cell batteries. And they have a very low self-discharge rate, similar to gel cells.

Unfortunately, like their flooded brethren, AGM batteries are prone to sulfation when left in a partially charged state for extended periods of time. Sulfation is a natural occurrence that over time will coast the cell plates with nonconductive lead-sulfate crystals. This effectively reduces the plate’s exposed surface area to electrolytes in the cell, and in turn reduces the capacity of the battery, ultimately rendering it useless.

This is a common cruising-boat issue that a conscientious captain can easily overcome with a little bit of diligence. The fix here is to make sure these batteries frequently get a full charge.

The good news is that unlike gel cells, AGM batteries can take regular and higher ampere and voltage amounts when recharging, with minimal fear of damage. In fact, one potential problem is that the alternator will be working so hard, it might overheat and be damaged. In the case of a shore-power-supplied charger, just make sure its capacity rating is adequate so it’s not running at 100 percent output constantly. If the charger was marginal when used with flooded-cell batteries, replacing old batteries with AGM technology could force the need for a new charger, again skewing that cost-per-amp-hour number.

Another thing to consider, if you’re replacing traditional batteries with AGMs, is their size and shape. Because of the way in which these batteries are made, they do not necessarily conform to traditional Battery Council International group sizes. Understand that the internal components for these batteries are compressed to maximize the amount of plate contact area with the glass-mat medium before being dropped into the outer case. The advantage here is that these batteries will typically have higher current densities, meaning more power for a given physical dimension; the disadvantage, however, might be the way that space for batteries was engineered into your boat. You might find that the battery storage area is going to need extensive modification to fit your new-age powerhouses. That’s another factor that could skew the cost-per-amp-hour calculation.

The advantages to both AGM and gel-cell batteries include their mechanical prowess. The pressing together and inherent rigidity of the gel in the gel-cell case creates batteries that can withstand vibration and rough-sea pounding much better than their flooded-cell counterparts. Mechanical failure of batteries is not that uncommon.

Ready for Lithium?

Over the past decade, the buzz in the world of batteries has centered on lithium ­technology. Here we have all the advantages of AGM technology, plus an opportunity to have even more current density coupled with an exponential reduction in weight.

What’s not to love?

Well, unless you’ve been living under a rock, you’ve also heard about boats using ­lithium batteries that have burned to the waterline. There are a lot of factors to understand here, which is why you need to think about a battery installation in a system context, and also consider the technology itself.

At least some of the fires caused by lithium batteries were due to the actual chemistry used. But there have also been issues with how they were manufactured (cleanliness when making the individual cells is imperative) and with the design—or lack of it—when it comes to battery management systems, or BMS as they’re called in the trade.

Today, virtually all the vendors I’m familiar with are using lithium-iron-phosphate or lithium-nickel-manganese-cobalt-oxide chemistries, both of which have good track records.

It’s important to understand that if a lithium battery does catch fire, conventional fire-extinguishing systems will not put out the blaze. Once the electrolyte catches fire (regardless of actual chemistry, all of the electrolytes are flammable), the only way to extinguish it is to cool it with water—lots of water! That said, the reputable manufacturers seem to have figured out all of this and do absolutely everything possible to ensure that a fire is ­extremely unlikely.

To keep things in context, consider this: Liquefied petroleum gas is extremely flammable and explosive, yet we use it aboard cruising boats quite regularly. If recognized standards for installation and maintenance are followed, any inherent danger is minimized to the point where we hardly give it a thought. The same thing needs to happen with lithium-battery technology. The American Boat and Yacht Council is working on ­developing a technical information report covering lithium-battery installations, and it is in draft form and being reviewed as I write this. Hopefully we can get a published document in place in 2020.

But I digress—back to the systems approach, which I can’t emphasize enough. If you are the technical type and determined to have the latest and greatest technology on your cruising boat, be prepared to spend some real money on all the elements required for the system to operate safely.

First, you will have trouble with your engine alternator running too hot as it works hard to keep up with the charging needs of these batteries. It makes sense to install a thermal sensor that shuts down the alternator if it gets too hot. Balmar offers this option with its alternator/­programmable-voltage-regulator combination.

Next, make sure your shore-powered battery charger has appropriate settings for lithium batteries. Then provide as much cooling as possible to the alternator; I’ve seen electric blower fans employed for this purpose.

Then, be sure you understand how the BMS on your boat functions. You might discover that the BMS is engineered to electrically shut down the battery/batteries if it senses a problem. Well, if the engine is running, this sudden shutdown could cause a voltage spike in your DC-electrical system, possibly damaging expensive and mission-critical electronics. Yanmar recommends installing a conventional battery as a system backup in case this happens. That’s yet another expense and one more thing to worry about.

On the plus side with either lithium or AGM technology, with careful planning and load analysis, the recharge absorption rate is so high that you might just be able to eliminate that AC generator to recharge batteries when offshore. Add some solar- and wind-­generated power, and engine run time with the alternator can be reduced dramatically.

Bottom Line on Batteries

I’m of the opinion that we are at an interim phase in technological development when it comes to batteries and the systems that surround them. We are seeing cities around the world that are mandating no fossil-fueled vehicles within city limits. Initiatives like this will force the play toward more and more electric vehicles. With that comes engineering investment that will pay off in the form of better batteries, enhanced safety protocols and trickle-down technology useful to the marine sector.

For now, though, I’m going to follow the suggested directive from the West Marine ­buyers’ group and go with AGM technology. An AGM TPPL battery is mechanically rugged, requires minimal maintenance, will probably work with my existing battery charger and alternator ­combination. Better yet, they can be heavily discharged and and recharged quite rapidly. That’s good enough for me.

Ed Sherman is vice president of education at the American Boat and Yacht Council, and is a frequent CW contributor on ­technical issues, as well as a longtime Boat of the Year judge.

The post Choosing Boat Batteries appeared first on Cruising World.

Batteries
As providers of power for engine starting as well as navigation and communication gear, lights, fans, pumps and other systems, your vessel’s batteries are perhaps the most important part of the electrical system. Making certain they are reliable and well cared for should be a top priority. Begin by inspecting terminals; these should be tight, and free of all corrosion. To prevent the latter, my preference is for a conductive paste, such as T&B Kopr-Shield, on the contact surfaces (it is not designed to be slathered over completed connections), which are then coated with CRC Battery Terminal Protector.

Ideally, batteries should be equipped with flag terminals, vertical lead or copper plates, through which a bolt is passed to secure cable ring terminals. Under no circumstances should wing nuts be used to secure ring terminals to batteries; always use a hex nut and bolt, preferably stainless steel or bronze. Batteries relying on automotive-style round posts must utilize an adapter lug or terminal. These are available in a variety of styles; however, those that rely on a through-bolt, rather than a cast-in-place stud, should be used. In order to keep resistance at a minimum, no more than four ring terminals should be placed on any single stud, and ideally, less. If any one of your batteries’ terminals supports more than four ring terminals, consider installing a bus bar to which some can be moved.

Because they convey especially high current, and since they are typically not equipped with overcurrent protection (i.e., a fuse or circuit breaker), battery cables used for starting purposes must be routed and protected with special care. As a result of the energy stored in the battery, and the diameter of the cable, a short circuit will spell almost certain disaster because the heat generation will quickly ignite nearby timber, fiberglass, insulation and so forth. The positive cable leading from the battery, or battery switch, to the engine starter, must be routed out of harm’s way, where it will not be repeatedly stepped on, or have gear stored on or dragged over it. Other than its connection to the starter, it must not touch the engine, transmission or motor mounts in any way, and it should be sheathed.

Unless contained in a box, positive battery terminals, as well as those on the starter post, must be fully insulated or enclosed. An ill-fitting rubber boot or cap is not sufficient; if any part of the terminal or stud is exposed then additional insulation must be installed. Starter cable runs and exposed terminals present a very real short-circuit danger; don’t dismiss these guidelines as unnecessary or overkill. On the subject of overcurrent protection, with the exception of starter circuits, a fuse or circuit breaker must be installed within 7 inches of every positive battery terminal. The distance between the battery terminal and the fuse or circuit breaker may be extended to 72 inches, provided the wire is supplementally sheathed within a conduit or ABYC-compliant loom.

Batteries themselves must also be securely mounted, ensuring they remain in place even in tumultuous sea conditions, or in the event of a knockdown or capsize. Most strap arrangements, unless they rely on a heavy-duty stainless-steel ratcheting buckle, are inadequate. Straps or buckles are simply too wimpy, the strap eyes are flimsy or the screws that secure them are too short (or worse, too short and made from mild steel). The most reliable battery supports rely on the aforementioned ratcheting strap, which passes under a robust battery shelf, or a tie rod with a strong back-clamp arrangement. While ABYC standards allow for up to 1 inch of battery movement in compliant installations, my preference is for complete immobilization.

Running Lights
Running lights, which are exposed to rain, spray and harsh UV rays, live a hard life. It’s no wonder I encounter so many that are either damaged or not working properly. In addition to ensuring they illuminate, you should inspect yours regularly to make certain the lenses are not cracked, crazed or faded.

For incandescent lights, plan on opening them at least seasonally to make certain they are free of corrosion and water accumulation. While conductive paste is well-suited to most electrical connections, because the positive and negative contact surfaces are very close together in most light bulbs, it should not be used in this application (it often relies on the common bayonet-style bulb used in most navigation lights, which could lead to a short circuit). Instead, light-bulb contacts benefit from a light coating of dielectric grease. Electrical connections at the bulb socket often rely on a set-screw-clamp arrangement. If it’s of the direct-bearing style — that is, if the end of the screw turns directly against the wires, without a clamp plate between the two (these lack ABYC compliance) — then a pin-type solderless terminal should be used. These connections benefit from the use of a conductive paste.

Also ensure that your navigation lights shine over the proper sectors and are not blocked by any parts of the vessel or structures or gear, such as arches or radar masts. Tenders suspended in stern davits are notorious for blocking stern lights, as are some masthead instrument and antenna installations. Additionally, don’t assume the navigation-light installation is correct simply because the vessel is new or the lights were originally installed by the builder. I’ve encountered many original-equipment navigation lights that were installed incorrectly, the wrong light was used for the application or it was not compliant with U.S. Coast Guard and ABYC standards.

Wiring

Because there’s simply so much of it aboard the average cruising vessel, the likelihood of problems related to wiring and termination is very high indeed. Routing and chafe protection, as well as installation technique, play a large role in improving reliability. With the exception of float switches, ABYC guidelines call for wiring to be routed above bilge water wherever possible, as well as isolating AC and DC cabling. Furthermore, wires should be supported at a minimum of 18-inch intervals, and strain relief should be provided. The latter is frequently overlooked. If, for example, you can tug on a cable that leads into an enclosure — for instance, a battery charger or inverter — the stress you are imparting should be conveyed to a strain-relief connector or cord grip, rather than to the connections themselves.

Most wires are terminated using solderless connectors, including ring, butt, bullet, fork and blade styles. All are covered by ABYC guidelines for their ability to maintain their grip on a wire, although the preference is for ring or fork or captive spade terminals. A No. 12 wire, for example, which is among the most common found in marine electrical systems, should not separate from its solderless terminal when a force of 35 pounds is applied for one minute.

For a larger battery-type cable terminal, the threshold is 150 pounds. Friction, blade or bullet connectors must, among other limitations, not separate when a force of 6 pounds is applied for one minute on the first withdrawal. There are actually very few locations where such friction connections are warranted. When you encounter any type of connections aboard, ask yourself if they will meet these guidelines. If you do your own electrical work, consider making up a test terminal or two to make certain your solderless terminal installations meet the standard.

Among the most common wiring termination issues I encounter are improperly sized ring terminals, and ring terminals installed in the incorrect order. The hole in the ring terminal must match the size of the stud or screw over which it’s installed. Invariably, it seems as if electricians and boatbuilders stock only two sizes of terminals, which makes improper matches all too common.

In order to ensure minimal resistance, ring terminals must be installed from largest to smallest, so the greatest amount of current is passing through the largest ring terminal. This error is especially common on starter posts, so check yours carefully. Yet another ring-terminal faux pas involves the installation of a washer, nut or other component between the ring terminal and the component to which it’s being connected (such as a bus bar, battery terminal or fuse block). In most cases, it’s a stainless-steel washer that is installed by a well-meaning individual who believes he or she is diminishing the likelihood of corrosion. In fact, this practice increases the likelihood of overheating and fire. Stainless steel, when compared to copper, is a poor conductor. Using it to convey high current (for example, with a windlass or starter) is like forcing water from a garden hose through a small funnel; the resistance is high, and when it comes to electricity, high resistance equals heat. Nothing should come between ring terminals and the object they are conducting electricity to or from. Period.

Finally, high resistance remains an ever-present threat where shore power is concerned. Statistically, shore power plug connections are among the leading causes of fire aboard boats. Get into the habit of inspecting both ends of the shore cord as well as the receptacles aboard the boat and ashore. If any appear to be overheated, melted or burned in any way, they should not be used. This is a problem that is largely prevented by making sure certain plugs and receptacles are clean and dry. If a molded cord end is dropped into the water, it should be thoroughly washed with fresh water, dried and sprayed with corrosion inhibitor that’s suitable for electrical connections. If it’s an assembled rather than a molded plug, it should be disassembled and cleaned before it’s used.

Corrosion One statistic holds that the global cost of corrosion is more than 3 percent of the planet’s GDP. For boats, clearly, it’s far greater. But much of this is preventable, particularly where your electrical system is concerned.

The selection of corrosion inhibitors is almost as dizzying as fuel additives. For the most part, they fall into two categories: light films that also include some lubricating properties, and heavy coatings that dry to a waxlike consistency. For components that are routinely removed and replaced, such as shore power cords and other plugs, light films are appropriate. For connections that are semipermanent, such as battery terminals, bus bars, ring terminals and so on, the heavier waxlike products make more sense.

For ring terminals, batteries, bonding systems and other screwed-in-place electrical connections — especially those located in damp areas such as bilges or sail and chain lockers — use the following approach: Make certain the power is off, then disassemble the connection. If there’s any corrosion or patina, clean it using a 3M Scotch-Brite pad. Then clean it again using a dedicated electrical contact cleaner such as CRC QD. Finally, apply either a conductive paste or dielectric grease to the contact area (either will work well, though I prefer a conductive paste with the aforementioned caveat regarding closely spaced positive and negative contacts); reassemble; torque; and then spray with the heavy waxlike corrosion inhibitor, my preference being the CRC Heavy Duty Corrosion Inhibitor.

Beyond this sort of prevention, there are a few other tricks that can be used to keep electrical corrosion at bay (female ends should be blown out with compressed air if possible). Every attempt should be made to install bus bars and other electrical components on vertical rather than horizontal surfaces. Doing so makes it less likely they will be dripped on or stand in water. Drip shields can easily be fashioned using Plexiglas (battery chargers and inverters, if not already drip-proof, should be installed with drip shields), or components can be installed in plastic electrical enclosures. When using the latter approach, wires should always enter from the bottom of the box. If they must enter from the side, include a drip loop to prevent water from using the wire as a leader into the connection area. While electricity and seawater don’t typically mix, a truce can be struck between the two, provided a proactive approach is taken.

Longtime boatyard operator Steve D’Antonio offers services for boat owners and buyers through Steve D’Antonio Marine Consulting.

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On paper, buying a storm-damaged boat can look like a real deal, but is it? The answer to that question is more difficult than you might think. The cost to fix or replace things like fiberglass damage, water-soaked upholstery and engines that might have ended up submerged can be assessed fairly easily, and often repairs are straightforward. But what about a boat’s electrical and electronics systems? The damage might not be so obvious, and a missed call on the extent of what work will need to be done can easily add up to a multi-thousand-dollar mistake. There are many factors to consider when we try to assess the relative health of any marine electrical system, and in the case of a damaged boat sold off as part of an insurance “deal,” it may be impossible to get the important history needed to make an intelligent evaluation. Without the ability to get accurate documentation of prior work done on the vessel, I’d avoid taking a chance on that particular boat. In other words, no deal! On the other hand, if you have access to work records and an equipment inventory, and you are able to learn more about how the vessel was damaged in the first place, you can at least begin to determine what might lie ahead if you do take on the project. Here are some of the questions I’d want answered.

What Happened?

The first thing to determine is whether the boat was exposed to salt water or fresh water. Certainly, in the case of vessels damaged by hurricanes that hit the Caribbean last fall the answer is ocean water with a heavy salt content. But sailboats along the U.S. Gulf Coast, depending upon exactly where they were berthed, may have been exposed to brackish or even fresh water.

Ocean water and salt spray can be particularly damaging due to its corrosive nature and relatively high rate of electrical conductivity. Fresh water, not so much.

Was the boat actually submerged, or was it just subjected to spray? Knowing this can make a huge difference in the potential damage, which will not be clearly visible once things get dried out.

How Good Was the Wiring?

How about onboard wiring? Wiring that meets U.S. Coast Guard and UL 1426 standards, which are also referenced by the American Boat and Yacht Council in its E-11 standard, is constructed to be water resistant. But understand, however, that much of the wire used in boats is supplied by vendors outside the United States, and it may not meet these same requirements.

Some years back, a group of members from the National Association of Marine Surveyors (NAMS) sponsored laboratory testing to establish the distance seawater travels between strands of submerged insulated marine-grade wire. Capillary action under the wire insulation was found to have caused water migration at least 18 inches along each wire tested within 24 hours of initial submergence in seawater. Rest assured that extreme corrosion will ultimately occur in seawater-soaked cables, and electrical performance will be diminished as a result. So, this matter of whether the boat in question was submerged or not is of extreme importance when establishing the history of your potential bargain purchase.

Were the Circuits Hot?

Another question to ask is whether the boat was plugged into shore power at the time of the event, and whether some battery-supplied circuits were powered up. These circuits could have been running until the boat batteries went dead or the shore power got disconnected, greatly amplifying potential damage.

Can I Fix It?

Can some waterlogged electrical systems be rebuilt as opposed to replaced? The short answer is yes, but with a caveat. Increasingly, electrical components are not engineered with any thought of reconditioning. Further to that, with things like engine starter motors and alternators, which can be rebuilt, it is getting increasingly difficult to find shops with the necessary capabilities. So, depending upon your location, the economics may dictate replacement.

Are Guidelines Available?

Searching for expert advice specific to damage to marine electrical systems turns out to be a bit of a challenge. I did, however, find a white paper published in 2016 by the National Electrical Manufacturers Association (NEMA). The paper, titled “Evaluating Water-Damaged Electrical Equipment,” provides sage guidance relevant to all things electrical. Let’s look at some of its recommendations.

First, contact the equipment manufacturer. Attempts to recondition equipment without consulting the manufacturer can result in additional hazards due to the use of improper cleaning agents, which can cause further damage. NEMA emphasizes the importance of working only with properly trained personnel, especially if reconditioning is the chosen path.

As for specific pieces of equipment, NEMA makes some very clear recommendations, which are broken down underneath this article into a variety of categories.

A Few Last Thoughts

Keep in mind that in many cases, equipment that has been exposed to water may look just fine after things dry out. Therein lies the problem. The old saying “beauty is only skin deep” may apply anytime wiring and components get dunked. Also, beware, equipment may function just fine at the moment you are checking it, but the damage may be hidden and will only manifest itself after more time has passed and corrosion of internal components sets in.

There are bargains aplenty in the wake of any major storm, but don’t get blinded by the dazzle of a meager price tag. Ask the questions I’ve posed here and you might find your deal of a lifetime is no deal at all.

Repair or Replace

The following guidelines are offered by the National Electrical Manufacturers Association as a guide on how to approach water-damaged electrical systems.

Electrical Distribution Equipment

Motor and Other Electronic Control Systems

Power Equipment

Circuit Protective Devices

Other Equipment

The post Beware Storm-Damaged Electrical Systems appeared first on Cruising World.

The bow was enveloped by yet another azure wave, and like all the others, it exploded into a plume of snow-white briny mist, stopping our forward motion. We were above the Arctic Circle, far from any sort of assistance, and I thought for the hundredth time: I wonder how the batteries are doing? Are they secure? Are the cables tight? Is anything chafing? These are the sorts of things I think about while on watch.

It’s not often I differ with the well-established guidelines set forth by the American Boat and Yacht Council (ABYC). The matter of battery installation is one of a handful of exceptions. Among other things, the standard regarding battery installations details the amount a battery is allowed to move after it’s been installed: “Batteries, as installed, shall be restrained to not move more than one inch in any direction when a pulling force of twice the battery weight is applied through the center of gravity of the battery as follows: vertically for a duration of one minute, and horizontally and parallel to the boat’s centerline, for a duration of one minute fore and one minute aft, and horizontally and perpendicular to the boat’s centerline for a duration of one minute to starboard and one minute to port.”

In the scheme of things, given this sort of latitude for movement, just about any piece of equipment — particularly items as heavy as a battery — will eventually come to grief. If a battery moves with every wave the vessel encounters — we’re talking hundreds, or thousands, of times in a given passage — the stress imparted to the battery, and the potential for chafe or the loosening of cables and connections, is very real indeed.

Based on my experience in both the boatyard and at sea, my preference is for the complete immobilization of batteries. This can be accomplished with a clamp-type strong back arrangement, or heavy ratcheting straps using stainless-steel buckles. Forget the wimpy nylon strap with a plastic buckle; while fine for a runabout or tender, it is simply inadequate for large batteries in seagoing vessels. Complete immobilization of batteries becomes more challenging when they are installed in boxes, particularly if the box is oversize, as so many are.

Contrary to popular belief, compliance with ABYC Standards does not mandate that batteries be installed in boxes. In fact, unless they are of the flooded variety, I’d argue batteries are better off without boxes; eliminating them offers better ventilation and makes regular inspection far easier and thus far more likely. Once again, the standards state: “Provision shall be made to contain incidental leakage and spillage of electrolyte. Note: Consideration should be given to: 1. the type of battery installed (e.g., liquid electrolyte or immobilized electrolyte); 2. the boat in which the battery is installed (e.g., angles of heel for sailboats, and accelerations for powerboats).” It makes little sense, therefore, to install a gel or AGM battery in a box, since leakage is essentially impossible. Flooded batteries, of course, do benefit from 100 percent containment, since they are prone to leakage and occasionally explode.

Fasteners used to secure battery boxes or trays must not be installed in an area where they might come into contact with spilled electrolyte; i.e., they cannot be inside the box, making a further case for an external clamp or strap arrangement. Additionally, unless these are through-bolts (most of the fasteners used for battery installations I encounter are tapping screws), it’s likely the installation will fail to meet the above-­mentioned static load test.

Finally, where batteries are installed in boxes, using the common shoebox-lid design, the apex of the lid must be vented to allow hydrogen gas to escape. This applies to sealed AGM and gel batteries as well; under overcharge conditions, these can vent hydrogen gas. Batteries that are poorly secured are more likely to suffer from loose and arcing connections. Add that to a design whose boxes fail to vent hydrogen, and you have an explosion in the making.

Steve D’Antonio offers services for boat owners and buyers through Steve D’Antonio Marine Consulting (­stevedmarineconsulting.com).

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Spring has sprung, so now’s the time to head down to the boat and get the preparations underway for summer fun. Among the many things you need to clean, tighten, repaint and adjust, your electrical system needs attention to make sure that it’ll give you reliable, safe service and not leave you hanging powerless at the dock.

First on the maintenance to do-list is to assess terminal tightness and protection. Uncovered electrical terminals on equipment such as the alternator, starter motor, bow thruster and anchor windlass are one of the areas often overlooked by boatbuilders, marine technicians and boat owners alike that can wreak havoc in very short order if not dealt with before the worst happens. In each of these applications, you are dealing with relatively high electrical current that can make sparks really fly if left unattended.

Each of these termination points needs to have a protective rubber or plastic boot over the positive terminal. These terminals need protection so the wire lug doesn’t accidentally come in contact with the equipment from which it protrudes. A positive lug in contact with an alternator, starter motor or bow-thruster drive motor can cause a sail drive or thruster lower leg to dissolve due to electrolytic corrosion in less than 24 hours! While you’re inspecting the boot, take a minute to get a properly sized wrench, and make sure the nut on the terminal is tight and corrosion-­free. Actually, a good look at all your boat’s electrical connections to make sure they’re tight and corrosion-free should be a part of your spring ­commissioning plans.

Jammed Motors

Motors are unique in their ­electrical fault properties. Devices with moving parts — such as bilge blower fans and pumps, and in some cases macerator pumps — are all vulnerable to a fault known as a “locked rotor.” This occurs when the moving part jams but power continues to flow to the motor, causing heat to build up.

In the case of newer ­macerator pumps, the issue has been resolved by using thermal circuit breakers that will shut off the power to the motor until the plugged system is repaired. In the case of virtually every other small DC motor on board, the motor must rely on a fuse installed nearby that is rated properly to blow and shut things down in time to prevent a fire.

The majority of motor circuits I check on board are overfused, however, meaning that the fuse is rated for more amperage than what the motor manufacturer recommends. This fuse rating is almost always found right on the motor’s label. Make sure that the fuse used in the power supply line is not rated at even 1 amp more than that specified by the manufacturer.

Hold Your Ground

Battery chargers and inverters, or inverter chargers, have a case-grounding requirement if they have metal cases. The American Boat & Yacht Council requires that these ground wires be sized at no smaller than one size less than the DC positive wire coming out of the device. What we see more commonly in the field are inverters with no grounding for the case, as shown in the photo on page 86. The lug shown on the Heart inverter just below the black DC connecting cable is what we find more commonly — in other words, with no wire connected.

The inverter or charger will function perfectly with this ground wire disconnected. But, if the rubber boot on the positive terminal gets violated and there is ever a DC-positive-to-case short circuit, the AC grounding wire (think green wire) will get called into action to carry the short circuit back to the source of power and trip a circuit breaker or blow a fuse. When this occurs, the green grounding wire is tasked with carrying more power than it was designed for, and it will burn up long before a fuse blows or a breaker trips. It goes without saying that onboard fires must be avoided at all costs.

Heart of the System

Your batteries are the heart of your boat’s low-voltage DC electrical system. This is an area where a lot of mistakes get made that can impact your safety and the reliability of your electrical devices.

ABYC standards are a bit tougher when it comes to battery installation than European standards, at least from what I’ve seen on many of the CE-marked boats I’ve inspected that were imported to the United States. For example, wing nuts, which often come with a new battery, shouldn’t be used, yet I recently found them in use on a brand-new CE-marked boat. Again, these are not compliant with the latest ABYC standards. In fact, wing nuts are now not to be used on wires sized 6 AWG or greater, based on ABYC Standard E-10. The reason is simple: They tend to come loose and could cause an arc and overheating, possibly even shutting down your electrical system completely or setting fire to nearby materials.

ABYC recommends ­replacing these with hex nuts and lock washers to eliminate this potential problem. Standards also require insulating boots over the positive terminals to prevent anything from coming in contact with them. Above and beyond that, ABYC recommends that batteries be installed in compartments made of material that won’t be damaged by exposure to the batteries’ electrolytes, should the battery spill for some reason. Ideally, a battery should be properly secured in a case made from fiberglass or some similar material, with both the positive and negative terminals covered with insulating covers, all in accordance with current U.S. standards.

One Last Thing

Finally, one of the biggest sources of trouble at marinas are the shore-power ­pedestals. Let’s face it, they live a tough life. A typical power outlet is out in the weather year-round, ­bouncing about on a dock 24/7. Such conditions are destructive for anything electrical. And the same goes for your shore-power cord. Check both ends as part of your spring inspection. If you see any signs of melting or burning, it’s time to replace the ends of the cord or get a new cord. Following these recommended checks this spring will go a long way toward keeping you sailing safely this summer.

Ed Sherman is vice president and education director for the American Boat & Yacht Council, and a frequent CW Boat of the Year judge and contributor.

The post Current Affairs appeared first on Cruising World.

Most everyone is familiar with the ubiquitous ground fault circuit interrupter, or GFCI receptacle. Among other locations, they’re found in household kitchens, bathrooms, patios and garages. They’re also recommended by the American Boat and Yacht Council (ABYC) for use in heads, galleys, engineering spaces, and on the weather decks of boats. Since their introduction in the late 1960s, they have no doubt saved countless lives. Requirements for GFCIs have been part of the National Electric Code for more than 50 years, with the first mandate being inspired by electrocutions caused by underwater lighting used in swimming pools.

While GFCIs have been widely covered, there is yet another shore-power safety device, one that was introduced to the marine market only within the past decade, that’s also worthy of attention. Referred to as an electronic leakage circuit interrupter, or ELCI, it offers yet another level of protection from shore-power faults, fire and electrocution. Much like a common GFCI receptacle (these have a comparatively low trip threshold of 5 milliamps, and as such are considered to be appropriate for protecting people), ELCIs remain in a state of equilibrium. As long as the current on the hot and neutral wires (the two current-­carrying conductors found in most AC electrical circuits) remains the same, they allow energy to flow. As soon as current finds an alternative path back to its source — through a green safety ground wire, the water or a person — the imbalance trips the ELCI’s ­circuit breaker and the power is turned off nearly instantly, often within 30 to 70 milliseconds. (Contrary to popular belief, electricity does not seek ground; it seeks to return to its origin, like the transformer at the head of the dock.)

While technically deemed “equipment protection” because of their 30-milliamp trip threshold, the goal of ELCIs is to interrupt current flow quickly enough to prevent electrocution, electric-shock drowning or fire — and for the most part, they do so quite effectively, saving countless lives every year.

As it was with the GFCI, the adoption of the ABYC ELCI standard was inspired by a number of electric-shock drownings, or ESDs. An ESD is different from a conventional electrocution; with comparatively little current flow, it can paralyze a swimmer’s voluntary muscle reflexes, causing the victim to drown, which can mask the underlying electrically related cause of death.

In addition to the trip threshold, the primary difference between the ELCI and the GFCI is the location in which it is installed. GFCI receptacles are installed where power is to be used, like the galley, head and so on. ELCIs are installed where power enters the vessel, near the shore-power receptacle. Think of it as a “whole boat” GFCI with some modifications. A primary shore-power circuit breaker is already required for every shore-power inlet, and in the case of an ELCI, it is often installed either in conjunction with this breaker or as a single combined unit, achieving the goals of overcurrent protection and fault protection. It’s important to note that the presence of an ELCI does not negate the need for individual GFCIs; both are still required for ABYC compliance.

ELCIs got off to a rocky start when they were first introduced in 2008. As is often the case, good intentions preceded the hardware with the ability to facilitate them; as a result, the implementation was postponed for a couple of years. Now, however, ELCI circuit breakers are readily available from several manufacturers in a range of configurations. With a few exceptions, new vessels or those that are being refit to ABYC standards must be equipped with ELCIs, and with good reason: They save lives. An ELCI can be added to virtually any vessel’s shore-power system provided it is free of faults.

Steve D’Antonio offers ­services for boat owners and buyers through Steve D’Antonio Marine Consulting (­stevedmarineconsulting.com).

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