10mm double insulated tails in henleys

[Chrisg88]

Hi all. Just to see your opinions on this.
Started work on a local authority housing job. Wiring showers in highflats.

The spec is 2 way rcd enclosure with 40a mcb and the other way blanked off.
We are to use 10mm tails into henleys. 25mm tails in use for cu and 100a main fuse.
I say we should be using 25 as its 100a cutout. But foreman says its ok as it wont pull more than 40a.

I would agree with him if it was a 40a stand alone rcbo only. But the extra way leaves it open for they 10mms to be overloaded.

Thoughts please

 

[deadshort]

I would cut the busbar …….. that will stop those pesky diy'ers

DS

 

[333rocky333]

Do you need a busbar, surely a 10mm link from the Rcd output to the Mcb would be neater

 

[Echo the husky]

Use a 3 module enclosure? Though there weren't too many about last time I needed one.

 

[flameport]

A 2 pole 40A RCBO would be ideal.

Not likely the 10mm will be overloaded even if another circuit was installed, 10mm singles are rated to about 65A.

 

[EFLImpudence]

Use a 3 module enclosure? Though there weren't too many about last time I needed one.

Isn't that a "shower consumer unit"?

The one in the OP must be a "garage consumer unit" so probably won't work for showers. I suppose I'd better add a smiley.

 

[ban-all-sheds]

But the extra way leaves it open for they 10mms to be overloaded.

And the existing main CUs don't contain enough ways that could be used to support loads which would overload the 25mm² tails?

Thoughts please

433.2

 

[Lectrician]

But the extra way leaves it open for they 10mms to be overloaded.

And the existing main CUs don't contain enough ways that could be used to support loads which would overload the 25mm² tails?

Thoughts please

433.2

There's a fuse protecting the 25mm tails from overload.

 

[ban-all-sheds]

There's a breaker protecting the 10mm² ones from overload.

 

[flyingsparks]

No there is only an rcd the op said

 

[ban-all-sheds]

Oh.

Then where is the MCB he mentioned?

2 way rcd enclosure with 40a mcb