12V control panel using MCB’s or fuses

[Peter]

In the process re-wiring my yacht, On thing I’m looking at is changing the 12V distribution pane. The current panel is an old style panel with each circuit having a switch and fuse using the “glass” type fuse. This does the job and it works. I’m thinking of changing for a new panel using MCB‘s, but this option comes at a cost. My question is, what are the advantages of using MCB,s if any over fuses.?

Thanks


Peter

 

[savageseadog]

They are reset easily which I suppose is an advantage. Other than that I don't see any great advantage to them plus there is the positive disadavantage of them being prone to corrosion etc. I honestly don't think they are a good idea for a seagoing boat unless there are sealed versions for this kind of use, perhaps they exist, I don't know.
In my opinion the simpler the better and I'm an electronics engineer.
A better plan (in my opinion) would be to spend the money on a bit more wiring and a extra switch/fuse panel or two. That way you can individually fuse more of the loads and fuse them correctly. You'll end up with a safer boat.

 

[simonfraser]

my "new" boat has mcb's & i'd swop them for fuses any time

with fuses at least i understand / can fix the problem

 

[TrueBlue]

I was inclined to agree with SeaDog - keep it simple - however, on reflection, methinks that you'll suffer more with corrosion on the switch plus fuse option than with MCB's (unless possibly if you use blade fuses; as used in cars).

When I built my boat I opted for MCBs because they avoided the need to carry fuses. Given that I've yet to have a genuine failure (as opposed to a trip cause by mine own incompetence).

I'd go for MCBs every time - if cost is an issue try a supplier who sells to the inland waterways market and ask him if his product is suitable for salty use.

 

[fisherman]

My fishing boat has MCBs, fitted in 1992. Never a problem, despite rough use, damp etc., and if you do get a short it's instantly identified.

 

[Anonymous]

I've had both and would have MCBs from choice without any doubt. Living aboard we do get the odd trip for perfectly good reasons - e.g. the shower pump gets clogged with hair and trips the MCB - and other similar examples. It is SO much easier to reset an MCB.

I am also an electrical/electronics engineer and appreciate the comments made by others but would add that if you have a nice dry boat you should be fine, especially if you are marina-based and leave a dehumidifier running all winter. If, however, yours is a wet or damp boat then either use fuses or, better still, dry it out as damp ruins your investment more quickly than any other factor.

 

[halcyon]

Would certainly go with circuit breakers, but you need to be careful what you fit. During the 15 years we supplied volume switch panels we used around 75.000 breakers, but all ( with limited exceptions ) the simples't we could find. ie simple bi metal with no pins, links, and springs, etc. We avoided switched type breakers, fitting a seperate switch only if it was required, also all switches were silver plated.
This again minimised possible failure points, this has resulted in nearly all the switch panels still working after upto 24 years at sea.


Brian

 

[PBooth]

Hi,
I've just rewired my boat and used circuit breakers. Every electrical consumer is wired directly back to the panel and has it's own switch and MCB. I used ordinary automotive toggle switches and thermal circuit breakers from CPC (less than 2 pounds each) the switches and breakers both use 6.3mm spade terminals, so if either go faulty, they can be replaced in seconds. I thought about waterproof marine components, but the cost was many times higher, so I carry spares that can be changed easily. I see all electrical components on a boat as having a limited life, so rather than going for cost-no-object marine parts, I use cheaper automotive parts and expect to change the odd one or two. Also, I spray all connections, switches etc with an anti-oxidation spray each year.

Peter

 

[philip_stevens]

I can second the KDD Powercentre switch panel components, as the KDD panel on our Duo is 20 years old, and has never had any circuit breakers or switches changed.

Brian knows what he is talking about.

 

[pappaecho]

I rewired my 28 year old Evasion 32 last year. The original loom had MCBs, which work after 28 years and I have retained them.
I fitted a separate panel for primarily electronic items such as log, VHF, GPs etc and used blade fuses, which have proved to be a blessing because in some cases I under estimated the load on the fuse and had to uprate. For example we have an electric pump to pump up the dinghy, and it blew 10 amp fuses on a regular basis, but replacing with 15 has been fine. Would have been more of a problem and expense with MCBs