Using MCB on DC system - Electricians Forum | Electrical Forum | An electrical forum for electricians in the UK

sparky_135 · 18-08-2008

Was asked a question today, and was not sure of the answer. Hopefully someone here will have a idea.

Someone wants to use a domestic DB on a narrow boat to distribute DC from the boats batteries to the required equipment, loads will only be small, no more than 20Amps per circuit.

Will MCB be ok to use on DC systems, as all DC sytems I have seen use fuses.

Look forward to your answers

tony.towa · 18-08-2008

Mcbs can be used on DC circuits but the characteristics can alter as a result. You need to check with the manufacturer that their mcbs are suitable for the application (I think you will find the majority will be for this type of use). One other thing is to check with regard to the wiring of narrow boats, they did used to have a seperate test procedure carried out by a waterways official cos the wiring standards were different. I am not sure if this is still the case as it has been some time since I was involved with one.

Spudmiester · 18-08-2008

For DC distribution in trailers I always use the good old Wylex fuse boards. This gives you the option to change to breakers if you want, and you will probably find the wholesalers will flog you them cheap. Mine did, £30 for about ten of the blighters.

spark-doctor · 18-08-2008

You can but re-setable blade fuses now. Merc vans use them but apart from merc i dont know where you can buy them.

It would be a much smaller fuse board.