Domestic mcb's for 12v DC

[johnad]

im looking to connect up some 12v circuits on a boat
(mainly lighting a radio a 12v tv and a car type usb socket)
i was reading online that some domestic type mcb's are OK to use on 12v DC
but I can't find a list of the ones that are rated for DC
I know marine rated DC breakers are available but I already have a selection of domestic ones and the enclosures sitting around and it would be good to use them if I can, I have some wylex, Schneider, mk, Marlin green, and hager mcb's
Also can I use a 100A main switch from a consumer unit as a isolator for a bank of 3 12v battery's ?
Any help, suggestions please

 

[Taylortwocities]

Fuses, use fuses.

 

[Jackrae]

Or something like this :
http://www.ebay.co.uk/itm/Boat-DC-1...734633?hash=item1eb078efe9:g:ooIAAOSwHQ9WaQ0n

 

[Spark123]

I think you need specific MCBs for DC, not just run of the mill ones. Fuses on the other hand like you get in a car are plentiful.

 

[JohnD]

Breaking a DC current causes a more persistent arc, because the voltage does not drop to zero a hundred times a second, so you need better separation and more durable contacts. It is more often found in boats, where ordinary switches will burn out quite quickly.

You might find some devices are marked with a DC and an AC rating, but I can't remember what to look for.

 

[skenk]

try here http://www.altecautomotive.co.uk/th...manual-reset-range-from-5a---30amp-1349-p.asp

 

[Echo the husky]

I've seen standard MCBs used in manufactured equipment on 12V DC, in control panels and so on. The arc will be much less aggressive than a 240V DC arc. The last one I saw was on the output of a power supply to a pool cover motor. It was a standard Merlin Gerin D 50A MCB.

 

[ericmark]

Gordon Equipment or Durite are one of the large suppliers of automotive parts. You will find a range here the automotive parts do not need the magnetic part so are smaller

and better suited for boat use. Durite does not sell to joe public but once you have the part number easy to find some one who sells their stuff. Tend to be more expensive than 230 volt stuff one shown goes for around £35 each which is why we tend to still use fuses.

As to battery isolator again get the part number then google. The standard CAT type isolator with switch rather than key is rated 125A the main problem is use of inverters. The 250A isolator I found cost less than the 125A version not a clue why.

 

[skenk]

the ones I linked to are only £4+vat. At £35 you've been had!

 

[ban-all-sheds]

So have you at £4

http://uk.rs-online.com/web/p/thermal-magnetic-circuit-breakers/7820867/

 

[RF Lighting]

If they're cheap at RS, they'll be cheaper at farnells and CPC

 

[Nozzle]

All about the "Rapid"

Nozzle

 

[johnad]

Thanks all for your replies
I did read that some 240v mcb's are tested at 12v and are also rated for dc ?
Has anyone got the manufacturers technical info ?
I was just hoping to save some money by using what I had to hand
But After your comments I may just get one of the simple blade fuse holders and use that but would the same go for using a 100amp main switch for a battery isolator ?

 

[Taylortwocities]

A 100A main switch is just a switch. It doesnt care if its switching AC or DC.

 

[Jackrae]

CE certified ? whatever that means