"Breaker breaker", calling the marine support department.

One of the most common calls to the service department concerns electrical items not working, no amount of switch pushing, swearing or worshipping the sea gods is going to fix it, a breaker has to be found and reset.

Circuit breakers

These are both devices that protect circuits, the main difference is a breaker is more of a mechanical device that can be reset and used again, whereas a fuse once it has “popped” or blown, must be replaced, it cannot be reset.

A typical scenario on the shorepower system

Boat is plugged into the dockside pedestal, cable is securely and correctly installed in it´s boatside plug fitting and there is no mains electricity showing on the panel. A telephone call is made and the technicians go off to investigate the problem. The typical process they will use, but not necessarily in this order, it will vary from boat to boat;

Assuming there is access to the breaker (RCD in Europe) on the dockside pedestal (photo below), most marinas, barring a select few have direct access to the breakers for just this sort of intervention, first thing is to press the test (white "T" in the photo) button on the RCD, if it trips we know there is an electrical supply at the dock.

RCD and two breakers installed in a dockside pedestal

Inspect the shorepower cable itself, is it properly plugged into the boat? inspect both ends of the cable, dockside and boatside, any evidence of burnt connections or a build up of green corrosion? As a precautionary measure (with the cord unplugged), a continuity test is performed using a multimeter to ensure no break in the wires of the shorepower cable.

The next step can be easy or a little more involved, the breaker in between the shorepower inlet on the boat and the main electrical panel on board needs to be checked. The reason this can be tricky is due to the location of this breaker, it can be clearly visible and accessible or mounted on an engine room or locker bulkhead somewhere. Something of note is that not all boats are equipped with this breaker, if the distance between the shorepower inlet on the boat and the main breaker on the electrical panel is less than 3 metres or about 10 feet, it is unlikely a breaker would have been installed.

On a lot of US built boats, especially those with the 16 amp rated shorepower cables for lighter electrical loads, the main breaker is often located right next to the shorepower inlet (photo below) and is very easy to check that is has not tripped. On larger boats with larger electrical demands and heavier shorepower cables, the breaker is often located on a bulkhead in the engine room or a lazarette. There is something important to note, the breakers in the photo below and the principle RCD in the photo above are of the double pole type, this means the neutral and live or phase wires are cut simultaneously when the breaker trips.

Breaker located right above power inlet, always of the double pole type

Finally we get to the main electrical or distribution panel (MDP), just to double check that the breaker has not tripped. Most of these checks can be accomplished quickly and easily and there is no need for a technician to come. It´s only when none of these checks fix the problem (or the breakers keep tripping after being reset)  a technician should be called. Find out where the breakers are on your boat and save yourself some money by using the above steps.

Not all breakers are created equal

One thing I must stress, if you are replacing or installing a breaker it MUST be fit for purpose, please buy from a well know manufacturer and ensure that the breaker is of the correct type and size for use. I have heard stories of off brand breakers not being made to exacting standards causing all sorts of problems, from not fitting to not working at all or worse still not tripping when they should, it´s for you own safety and this is an area that it simply does not pay to save money.

One of the most important things for a breaker on a boat is ignition protection, this means it´s safe to install on gasoline or petrol powered boats.

On a lot of boats, the breakers are used as switches as well, they perform double duty, they trip in the event of a problem and also turn items on and off. This is more common when you have an electrical panel inside the boat and need to turn things on and off. High amperage rated breakers can be used to isolate circuits, a typical example is an anchor winch.

110 amp DC breaker for an anchor winch

Non interference

There are certain types of breakers that are sort of “non user interference”, by this I mean they are permanently in the “on” position, this is usually so that they cannot be switched off by accident but will still trip in the event of a problem, examples include bilge pumps, battery charger connections and stereo permanent memories. The usual way to get the breakers to forcibly trip for service is using a small flat screwdriver pushed into the slot in the front to activate the trip mechanism, you often see these types of breakers installed into battery switch panels.

Non interference breakers on a battery switch panel

RCDs and GFCIs

Following on from the double pole breaker, a lot of the double pole breakers are in the form of something called an RCD (Residual Current Device, in Europe) or a GFCI (Ground Fault Current Interrupter in the US), these devices go by other names too and there are multiple types but, their function is basically the same.

In the basic mains electrical system there are 3 wires, an RCD or GFCI monitors the difference between the phase or live and neutral wires, in the event of a difference of more than “X” amount of milliamps (depending on the rating of the breaker), it trips and cuts the electrical supply. The path to ground is never ever cut for safety reasons. In Europe every marina I have ever been to has an RCD on the dockside shorepower connector.

A lot of US built boats have GFCI breakers dotted around the boat, especially protecting areas where water and electricity are likely to meet, bathrooms, exterior wet bars and galley areas are examples of the circuits that are likely to be protected. A lot of call outs are simply to reset these breakers, knowing where they are located can save plenty of time.

Summary

Learning where the breakers are on your boat can save you a lot of aggravation. The most common calls to boatyards, marina offices and technicians is simply to reset a breaker, anchor winches and dockside shorepower being the most requested.

An anchor winch breaker installed in a convenient position

 

I have had to reset breakers that were in such awkward places that I had to empty lockers to get to them, climb into engine rooms or over hot exhaust manifolds, less than ideal positioning. Breakers are often located near to batteries and there are certain rules regarding their placement, that said, if a breaker is so difficult to get to, I would move it to somewhere it can be reached and reset more easily, this may involve a bit of electrical work to stay safe and comply with regulations but I can assure you it will be worth it, nothing ruins a nice afternoon faster than having to faff around and move people around in order to reset the anchor winch breaker because it is installed in an awful place.

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