Rcd Upgrade Next To Rewireable Fuse Board.

[Sam Roberts]

I have been asked to fit a few new sockets in a house but have come across a garage RCD CU supplying the sockets and lights and a shower RCD CU supplying the shower. Theses have been fed directly from the fuses that were supplying the original circuits, as in T+E into the supply side of the new CUs. I've not seen this before unconventional as it may be surely improved the safety of the circuits. 

 

[Sam Roberts]

Just noticed 30A rewireable supplying the shower CU on a 40 A, I'm guessing best bet is to at least replace the 30 A rewireable with a 40 A plug in MCB? Suggestions please.

Just noticed 30A rewireable supplying the shower CU on a 40 A, I'm guessing best bet is to at least replace the 30 A rewireable with a 40 A plug in MCB? Suggestions please.

 

[Andy™]

fairly common to add an RCD alongside the board, done it myself loads of times although i usually use a 2 way DIN enclosure instead of garage CU

 

[ProDave]

As it's such a mess, I would at least be talking to them about fitting a new CU.

Offer them a bargain price to have one of the "old" plastic ones now being offloaded cheaply (SF selling 10 way fully loaded BG plastic boards for £40)

What size wire is in that shower 30A fuse?

 

[Andy™]

What size wire is in that shower 30A fuse?

30A...

x3

 

[Murdoch]

May be you should suggest a fuseboard upgrade .....

 

[Evans Electric]

As Dave says ,  the right path is to get rid of all the "add-ons" and fit a new board , but thats up to the customer .

 I wouldn't worry too much about the rewirable fuses which , I presume , only protect a short length  tail into the garage units  which , I presume , contain an MCB & an Arseydee .  

 

[Rob_the_rich]

Why replace the 30a bs3036 with a 40amp plug in mcb? The existing is wrong and does not comply with the regs. But what you are proposing also does not discriminate and will not comply too. Plus, you would need to do full EIC and notify, since it is in effect a new circuit. What rating is the shower, what size is the cable and what seems to be the installation method?

It also seems there is a problem with discrimination between the "garage CU" mcbs and the 30a bs3036 supply, which, if the 3036 fuse blows, would lose all the lights in the house as well as the power from the sockets.

 

[binky]

I would check what fuse wire is in the carrier.

Nothing wrong with external RCD as per Andys response. addtional MCB is unnecessary. If fuse wire is still 30A than it is probably over-protected and not a well thought through set-up. As Rob says need to know cable size and shower size.

 

[davie garden]

Plastic CUs aren't allowed any more, that's why you can pick them up dirt cheap. A new metal CU with enough ways (and maybe one or two spare ways) is the answer.

 

[Andy™]

plastic CU's are perfectly acceptable in non-domestic, so saying they 'arem't allowed any more' is BS

 

[Murdoch]

Plastic CUs aren't allowed any more, that's why you can pick them up dirt cheap. A new metal CU with enough ways (and maybe one or two spare ways) is the answer.

Hum.... wrong, you can install them until the end of 2015.... and they are perfectly OK for non domestic installs

 

[pewter]

you can still have a plastic consumer unit in a domestice house after 2015 if it  is in a fireproof enclosure.

 

[Andy™]

and what makes this even worse, he's a college lecturer who's supposed to be teaching new electricians... maybe he needs to go on a course instead...

 

[Blue Duck]

a 5 week one?

 

[Doc Hudson]

Plastic CUs aren't allowed any more, that's why you can pick them up dirt cheap. A new metal CU with enough ways (and maybe one or two spare ways) is the answer.

Factually incorrect statements do not really help much.

Doc H