split 10mm singles to 6mm singles & earth block terminal

[mattrandall]

I have found in my kitchen that a 10mm supply in singles has been installed for my 2 new ovens. As the ovens are isolated independently the 10 mm has been split into 2 x 6mm singles. An earthing block terminal (bare metal type as you would have for connecting multiple earths ) has been used and housed in an enclosure (ip rated although it's inside). Is this a viable solution and will it be ok? The ovens are 4 kw each so pull a combined total of 32 amps roughly at max. Please help as it's being boarded in shortly and access will cause damage

 

[paul b b]

Hello and welcome,

Please can you inform us of the braker size.

How are they split? If they are in a screw type box you cannot board over it as you may need to get to it.

 

[m4tty]

Have the singles been installed in conduit/trunking or run on their own?

 

[mattrandall]

They are on a 40a type b mcb. The cables are in conduit 25mm. The earth blocks are in an outside rated plastic enclosure. The earth blocks have 8 terminals. The phase, neutral and cpc have their own blocks and separate enclosures

 

[apprentice87]

Hi, Photo needed i think...

 

[paul b b]

Is the cpc also 10mm?

 

[mattrandall]

All conductors 10mm. It's has only been done as couldn't get terminals into a conventional jb. Didn't know

If anyone had used this principle?

 

[paul b b]

Matt, why not change the 6mm for 10 if you are worried. 6mm is ok on a 40a mcb dep. ending on method of install. 10mm for a cpc is a bit overkill.

I would not plaster over that box. you may need acsess to it.

Have you tested anything?

When ever i have instslled 2 cookers from 1 mcb i looped the feed in from first isolator rather than splitting feed

 

[batty]

Generally what i try to do if say you have an oven and hob is take 10mm into switch and then two times 6mm out from bottom of switch out to oven and hob that way you need no joins you can easily get 2 x 6mm in a 45 amp switch if its decent quality. If the oven only needs 13 amps i put a 13 amp socket under the kick panel job done. Maybe an option in what you are trying to do.

 

[PC Electrics]

The 6mm is okay on a 40A. However you cannot board this arrangement in.

Why didn't you take the 10mm directly into a cooker control unit and then use 2 x 6mm from the switched side?

And, why did you waste your money on 10mm when 6mm would be more than adequate? Without knowing the oven models it's impossible to be sure, but they could probably have gone on a 20A and certainly a 25.

This arrangement strikes me as a very poor solution to splitting a supply. There are plenty of other better ways to do it, and products available to help you (eg the Click dual output cooker connection unit)

 

[SPECIAL LOCATION]

1. You CANNOT board up these connections if they are a non-permanent jointing method (e.g. screws).

They MUST remain accessible for inspection and testing.

1(a) That is of course assuming it is being done to comply with current wiring regulations BS7671?

2. If 1(a) is true then It will also be needing to be notified to your LABC for a part P compliance certificate......

2(B) that is of course assuming these cookers are in a domestic kitchen?

3. If non of the above are correct and it is just a DIY bodge I would be very wary of advising anyone on an open forum to connect up this arrangement to high power appliances.

Your phrase

"I have found in my kitchen that a 10mm supply in singles has been installed for my 2 new ovens"

sounds a bit contradictory to me....'I have found' sound like existing wiring that was originally installed....?

but 10mm singles would be a bit out of the ordinary for an old cooker circuit...?

yet 'Supply for 2 new ovens' sounds like someone specified what was to be installed....

but how come you didn't know it would be there?

I am a tad confused by this thread!?

obscure or weird installation methods often = DIY electrics rather than qualified Sparks.. (though not always!!!!!)

:C

More info needed me thinks?

 

[mattrandall]

Can an earthing block be used as a connector strip in principle? For phase ideally as got 1x10mm and 2x6mm cables to join eg to split the 10mm

Into the two 6mm conductors. It will

Be then placed in an enclosure so as to be like a junction box.

 

[NozSpark]

Certainly not if you are going to board over them as in your other thread.

 

[mattrandall]

They will be accessible from the room above via floorboards. Just wanted to check that it is capable of being used as a connector ( if not best practice tho ) thanks for ur advice

 

[NozSpark]

That is not classed as accessible

IMHO you need to get someone in to look at it

 

[paul b b]

ROTFWL

Certainly not if you are going to board over them as in your other thread.

do they have a rating on them?

Is under a carpeted floor acessable?

Why dont you join them in a isolator box?

 

[mattrandall]

Will do. Been a headache from this "sparks" from the beginning. All the gear and no idea I'm thinking ! Cheers for ur advice

 

[paul b b]

Matt, are you not a spark then? Or are you asking for someone else? Or are you a diyer?

 

[mattrandall]

I'm looking for advice. I'm nearing my finals of my c&g 2330 L3 and just done my 17th Ed. This electrician is offering me work alongside him so I can learn practically and back up my theory. Just don't want to pick up bad habits. Also hadn't seen this done before. I didn't know if he could of used a 45a jb if it exists. The 10mm cable is not long enough to run to the switch which is why he did the connection in the ceiling. It is only for the two ovens to run off as the hob has a separate 6mm cable which is the original oven feed. Sorry if I haven't explained this clearer earlier. Just wondered if the block would be an acceptable way of connecting the 3 cables. Any other

Ideas I can put to him. The 10mm like I say isn't long enough to get to the switch which is why he's split it there. Plus he wants to be able to isolate the ovens individually hence 3 x 45a switches !

 

[SPECIAL LOCATION]

Can an earthing block be used as a connector strip in principle? For phase ideally as got 1x10mm and 2x6mm cables to join eg to split the 10mmInto the two 6mm conductors. It will

Be then placed in an enclosure so as to be like a junction box.

Erm????

NO!!!

headbang :red card

Fails to comply with regualation 134.1.1 IMHO

AND..

if anyone dared to suggest it was acceptable on an open public forum then I would be PM'ing all the Mods & Admin to get the thread removed....