RCD main switch board

[mport]

Hi all,came across a small fuse board feeding 4 16a circuits and the main switch is a 63a 30mA rcd, am i right in thinking that if i install a separate main switch in an enclosure and fed the rcd board via a suitably sized mcb in that enclosure then that would comply with the current regs!? Cant change the board,just want to get it to comply,let me know if i'm on the right track or way off!!.

 

[Manator]

Hello and welcome to the forum.

Do you intend to add another circuit? Or just some type of upgrade? The way you describe the current layout I see nothing wrong other than the nuisance caused by the RCD tripping and throwing all 4 circuits out of action.

 

[Doc Hudson]

4 16A circuits, are these off peak storage heaters by any chance? What aspect of the current arrangement do you suggest doesn't comply with regulations? Welcome to the world of posting mport.

Doc H.

 

[mport]

Hello,apologies for the misleading post,got my mate to post it for me and he didnt word it correctly,i,ve just installed the wiring for 4 water heaters all 2kw,in a commercial/office building,all existing circuits are fed from an old style 3 phase cartridge fuse board that has no local isolation and i was provided with a 6 way board with an rcd main switch,i am unable to swap for another board so with it being a new addition i'm thinking i have to make it comply and i reckon to do that i'm gona need a separate enclosure with a 100a main switch feeding a 50a mcb which would then feed the board,does that sound about right??

 

[NozSpark]

I don't get the reason why you'd need the 100a main switch and 50a MCB... Surely you have overload protection at the 3ph board??

I guess that the 3ph board has an external isolator?

Now, to your new board,,,, its in a commercial building. Do the circuits actually need to have RCD protection? If not change the RCD for a main switch!

 

[mport]

no local isolation at the 3p board and we've taken the feed for our new board directly off the busbar,as for the rcd isn't this where you take a step into the murky waters of 'the skilled person' and what that means,besides it's been installed at a BT depot and those boys only know how to work stuff that rings!

 

[Sidewinder]

mport,

If it is in a BT depot then it is under the control of a skilled or instructed person it has to be by statute law.

 

[binky]

mport,If it is in a BT depot then it is under the control of a skilled or instructed person it has to be by statute law.

So answer is swop out RCD for a main switch - you don't need RCD for this environment, unless you perceive the risk is high enough to merit it. As a general rule, the only time I normally RCd anything in commercial premises is for an outdoor socket

 

[Sidewinder]

Quite binky.

 

[mport]

thanks for the advice!