Circuit breakers/fuses

[Guest]

I am the owner of a 32 feet sailboat from 1978 with a new diesel engine. I have decided to rewire the boat during next winter. The rewireing will include installation of a new switch-panel (12 V). Should I go for a model with "automatic breakers" or buy a cheaper model with "normal" fuses? If I go for "automatc brakeakers" I probably also have to have spare breakers. Is it easy to replace an "automatic breaker"? Which model should I choose?
I f you could help me to answer these questions I would be thankful.

Best regards

Tor from Oslo (in Norway)

 

[gunnarsilins]

I would go for automatic fuses. No need for spare fuses and immediate indication of overload are strong arguments.
If you use a variety which doubles as a circuit braker the cost will not be that much higher. A good quality switch is not cheap and then you have to add the cost of a suitable fuse holder.
Besides, you are not tempted to use a higher rated fuse in a overloaded circuit and thus risking overheated wiring and a possible risk of fire.
There is Swedish company called Odelco selling good quality circuit breakers/automatic fuses, complete switch panels in various sizes and other good stuff for electrical installations on yachts. They are very helpful, try to get in touch with them.
Hilsen!

 

[oldsaltoz]

Hi Tor.
Circuit breakers are a great item, no more hunting around in the dark to find a fuse that has the correct rating and size. I put a set in about 5 years ago and have had no trouble at all. Like you I decided to rewire the boat, I used tinned wire throughout and when completed sprayed the back with an electrical sealant designed for electronic circuit boards available at most electrical supply shops.
The only spares I carry is a couple of ‘in line’ fuses that can wired in with little trouble but I have not had to used them yet.
Old Salt Oz

 

[vyv_cox]

I have owned my present boat for something like six years. I have made quite a few additions and changes to the wiring over that period. I carry loads of spare fuses but I have never blown a single one in all that time.

I do think that good quality breakers give a little more protection than a fuse, in that they can sense a current increase that might not melt fuse wire. However, a sense of proportion is needed as the cost of replacing a large number of fuses could be pretty high.

 

[Guest]

This may sound like overkill but I think both c.bs and fuses. The c.bs protect the wiring and the fuses the individual equipment. Each of my wiring circuits (nav lights, cabin lights, nav aids etc) is protected by circuit breakers but each piece of equipment has its own fuse.

Tom

 

[Guest]

Thank you for your replies !

I have got the impression that panels with "automatic" breakers are more popular than panels with normal fuses despite they are more expensive. One important argument aganst the fuse-panels seem to be that you have to replace blown fuses. However, I am wondering what will happen if I get a problem with a breaker for a vital instrument. Will I be able to replace it in a simple way? I have been recomended to buy a high quality panel. If any of you know of a survey on panels I would be greatful to know.

Regards

Tor

 

[vyv_cox]

A breaker can be re-set, it doesn't need to be replaced. Normally press in the button. It's worthwhile trying to assess the cause first or you could damage the wiring or appliance.

You can build your own panel for custom requirements, not too difficult if you can do simple metalwork. Components from RS. E.C. Smith used to do some real Rolls-Royce affairs, not cheap.

 

[davidt]

I have re-wired my Trident Voyager 35 and installed a mains electric circuit as well.

For the 12v system I used illuminated rocker-type circuit breakers manurfactured by E-T-A and bought from E.C.Smith. I had a panel made from anodised aluminium by a local sign makers. (They had the facility to engrave aluminium and they were able to machine -cut the slots for the circuit-breakers) It worked very well except for one thing - all the illuminating diodes burnt out after a few months. The problem was caused by my TWC which charges at 14.4v whereas the diodes are strictly 12v. E-T-A replaced all my breakers at cost with 24v illumination diodes and these have been fine. They are dimmer, but that is a help - the panel no longer looks like Blackpool Illuminations when half a dozen circuits are switched on!

When I did my mains circuit I had a panel made to my specification by Taplin International. It is excellent quality and it did not cost the earth. You can contact them on 023 80 232304

 

[Guest]

I'm rewiring too, but I haven't located a reasonably priced supply of tinned wire - where did you get yours?

I bought my switches, circuit breakers and buss bars from GS Controls (www.gscontrols.com) at a very reasonable price (£1.10 for switches, £1.20 for circuit breakers).


//www.trumphurst.com/ Trumphurst Home Page

 

[oldsaltoz]

Hi Nikki
I purchased my tinned wire in Australia, but you can do what I did there; just take the phone book and look up the suppliers of cable in your area, tell them what you want and get a price. Ask them for as much information as possible, the manufacturer, the type, the cable cover material and colours available; I used 300 metres on a new 33 footer and 140 metres re wiring a 28 footer, the most economic way to purchase is in 100 metre rolls.
You will save heaps by ringing as many suppliers as possible, each one will give you a new bit of information you can use when ringing the next.
I hope this helps.
Note, if you are terminating your wires into blocks with screws to hold the wire, have a look at some of the products available to prevent verdigris, (blue / green)
Old Salt Oz

 

[Guest]

Hi Oldsaltos !

Perhaps you can help me to find an answer to two more questions?

A German sailor has told me that he would install no cables in his boat with a diameter of less than 2,5 mm. The size of the wire should as far as I know be calculated based on max consumtion and the length of the cable. However, is it a good investment to put in oversized cables ?
Today our boat has double cables (+ an -) to every consumer. I wonder if I instead should have one commond minus cable from back to front. This will probably reduce costs and make it easier to discover possible future faults ?

Regards

Tor

 

[oldsaltoz]

Hi Tor.
I run oversize wires to reduce the resistance and allow for future additions. Also try to locate your batter/ batteries as high as practical, this keeps them above the gas leak zone, water, in the event of a disaster and don’t forget electricity is like water it flows downhill better than up.
As for running a singe earth / return cable for all circuits, not a good idea, one cable joint fails or gets broken and the lot goes dead, a short in one circuit may cause problems in another, like those little computer chips in just about everything. If you want to reduce the cost of cable by running fewer earth returns, then split your circuits so that some lighting is on one return and the rest on the other and so on. Any critical or safety items should be kept separate.
By the way, make a drawing of each circuit and if you mount your cables so that you can access them for testing and fault finding, consider building in a test lamp, that way you won’t be looking for one in the dark.
By the way, the old (not bold) electricians have a saying….One Flash And Your Ash.
Hope this helps
Old Salt Oz

 

[Guest]

Hi Old Salt Oz !

Thank you very much for your interesting reply.

regards

Tor