Hunter 27 Breaker Panel

[Whiskey Tango]

Dear Fellow Hunter Owners
I am looking to renew the DC circuit breaker panel on my 1980 Hunter 27. The original Breakers do not have the amperages labeled on them. Does anyone know where I can find this information.
Any help is greatly appreciated.
Happy Sailing

 

[Sailor_Jeff]

Can you post a photo of your old breakers?

 

[TDudley]

I have your boat and I replaced my breaker box with a Blue Sea DC breaker pannel. I dont think you would want the original kind since they are old technology. I got the breakers that came standard to the panel (15 amp), and if I need smaller fusing I will do it after the breaker panel with a seprate fuses or buy a breaker to fit the panel. It will depend on what I am fusing. The old panel had AC and DC together on one panel. This also seemed a little dated and not so safe. I would bet it does not meet today's standards. I seprated the two and put a new AC panel in as well. This did not cost a fortune since the panels are small.

The other and somewhat bigger consideration is also moviing the fuse panel and other electrical components all together to a higher location. I love my boat, but why the fuse pannel was put so low in the boat I will never understand. If it was proximity, just up the wire size a little. My boat is 34 years old and I know for a fact that it has had water in her very close to if not into the fuse pannel.

I moved my new fuse panel above the pilot birth (which is on the port side of the boat) on a plywood board that holds the pump control wires (also originally located in the bottom of the boat), AC breaker pannel, and the on/off switch. It hinges on the wood panel that runs along the pilot birth from the nav station so that I can get to the back of it. I plan to make this more formal in the near future by building another board with all of the electrical components on it, This has elevated the components from anywhere from 6 inches to 2 feet above where they once were.

Something to think about.

 

[Whiskey Tango]

Jeff-Mac22, I will post photos this evening.
TDudley, thank you for you input, I greatley appreciate it. I am in fact planing on moving the panel above the nav desk. If I were to instal a panel with 15 amp breakers and let's say for example the anchor lights were originally hooked up to an 8 amp breaker for instance, would that be acceptable. I thought I had to replace the breakers with the existing amperage values suitable for the connected components. But the originals have no indication. Or how would I determin the amps of each component. The cabin lights I can figure out, the fixtures are labeled, but certain things are not labeled or not accessible, so I thought it prudent to use the same amp breaker that existed. If my logic is flawed I would appreciate any clarity on the subject. Thank you again.

 

[TDudley]

It it would be acceptable to use a 15 amp breaker in place of a 8 amp fuse. you either need a circut breaker of the correct size or a fuse after the circut breaker. I use my curcut breaker as an off/on switch as the original did. If you have the original fuses you can certainly use them as a reference. As for amps needed, you need a couple of things. One is the Blue Sea Wiring Sizing chart. this will help you figure out what protection you need. If you dont know the amps used by a item, but you do know watts, divide watts/12V. this will give you amps. If you dont know either, look up simular items on line and use the amperage its shows for that item. Nigel Calder has a few books out that do discuss the typical amperage of items on a boat as well as a host of other important topics. If you dont have his books, STOP and buy as many as you can. Hope this helps.

 

[Whiskey Tango]

Thank you again for all the helpful information, I will most definitely pick up the prescribed reading before moving forward.

 

[Whiskey Tango]

These are images of what Im working with, I've inherited quite a mess. I am unaware of any fuses that exist after the breakers, so I will be using the new breakers for there intended purposes, and not just as a switch. I will do an audit of all the components to determine the appropriate amperage that the breakers should be.

 

[Sailor_Jeff]

Yes, those are standard marine breakers. The photo you sent is an "A Series" magnetic marine circuit breaker from Carling. This is rated to also be used also as a switch. They have them at our local marina new and West Marine.

You size the breaker based on the smallest wire hooked to it. Generally speaking this type of breaker is used to protect the wire from starting a fire because of overheating because of too much current being drawn through for its size. Smaller the wire smaller the amps, bigger the wire bigger the allowed amps.

You can look it up on a chart but most people use 15 amp with 16 gauge wire. You can use bigger breaker on this size, but, 15 is big enough for most people.

Seems logical that your don't want to be at sea with a boat on fire because something shorted out and the breaker did not snap open before the wire overheated. Then again, it would also seem logical you don't want to be at sea on a boat on fire for any other reason either.. <grin>

But most electronics have a fuse or circuit breaker on the device to protect that device. It is up to you to protect your wiring to the device so it does not smoke..

These are superior and worth the investment for the extra quality they offer.

The following is from Marine advisor:
Here is an over-simplified guide to size selection:
•The amperage of the load largely determines everything else.
•This, along with the distance to the load, determines the size of wire based on the wire selection tables.
•The current carrying ability of the wire determines how big a fuse to use.

Circuit breaker size selection

Selecting the correct breaker size is a real problem for most custom and standard panels on the market. The issue is the impossibility of anticipating what breakers will be needed on a distribution panel, since all boats are different. Blue Sea Systems solves this problem simply. They reason that the majority of circuits onboard will have loads of less than 15A (certainly that is the case with most electronics, lights, pumps, small refrigerators, etc.). They also reason that most wire used for circuits will be at least 14-gauge, although it may be as small as 16-gauge. Therefore, they supply their panels with 15A circuit breakers throughout the panel, for the following reasons:
•If the circuit uses 16-gauge (small) wire, which has an ampacity of 25A, the breaker will protect it.
•15A is larger than most loads on a boat.
•A small fuse can be used at the load, or a smaller breaker substituted in the panel if smaller current protection is necessary.

 

[Whiskey Tango]

Thank you to you both for for the diligent and thorough advice. I have found the exact same breakers right here at SailboatOwners.com, I am also pricing out panels from Blue Sea. I also ordered two books on sailboat electrics by Nigel Calder and Don Casey. I figured this is a topic in which it never hurts to know too much.
If i can pose one more question on the subject, as the two of you are a wealth of knowledge. The shore power breaker is three pole, where as most of the literature i come across talks about two pole breakers. In fact i haven't come across any talk of three pole at all. Should I stick with a three pole, and whats the reason for one over the other.

 

[Sailor_Jeff]

The shore power breaker is three pole, where as most of the literature i come across talks about two pole breakers. In fact i haven't come across any talk of three pole at all. Should I stick with a three pole, and whats the reason for one over the other.

Yes, if a three pole was used before use it again with your new installation.
Why use a three pole for single phase shore power? in short, I believe you use a three pole to totally isolate the ship from all three wires of single phase shore power when turned off. This is for a number of reasons including safety from stray leakage currents on the neutral and ground lines coming from faulty shore power sources. It was explained to me that generally, you only use single pole breakers for your DC equipment on ship/boat between battery and equipment. Another reason most people only use single pole for your DC breakers is that double or triple pole breakers are too wide to fit in the panel.

I have seen double pole breakers on the AC power lines, again AC is a bit different safety wise. It isolates the whole appliance when turned off.

Also Remember, use only marine grade wire throw away old automotive wire previously used.

Good books you have, read them carefully and completely. When in doubt, seek the advice of a marine electrical engineer or experienced marine surveyor.

 

[braol]

Just for the record, some people have had luck in replacing the old, stiff A/C wiring with good old orange extension cord...

 

[Sailor_Jeff]

Just for the record, some people have had luck in replacing the old, stiff A/C wiring with good old orange extension cord...

Was told when I was in school that going to stranded wire can be good in the hull but, using an extension cord for wire in the hull is not allowed because when / if it over heats it puts out toxic fumes that can render someone unable to function in seconds or minutes.

The only difference in Marine wire and common wire is the quality of the insulation and its resistance to out gassing toxic substances when hot.

If you are out on deck, not a big deal because the fumes dissipate in the atmosphere. But if you have to go below deck to turn off a switch or if you are sleeping, then by the time you wake up, you might not be able to...

 

[Lusitano]

Thank you to you both for for the diligent and thorough advice. I have found the exact same breakers right here at SailboatOwners.com, I am also pricing out panels from Blue Sea. I also ordered two books on sailboat electrics by Nigel Calder and Don Casey. I figured this is a topic in which it never hurts to know too much.
If i can pose one more question on the subject, as the two of you are a wealth of knowledge. The shore power breaker is three pole, where as most of the literature i come across talks about two pole breakers. In fact i haven't come across any talk of three pole at all. Should I stick with a three pole, and whats the reason for one over the other.

That's a 50 amp breaker!