25mm and 16mm tails in same Henley block?

[don Logan]

Hi, i've ran a radial into an extension. There are no spare ways on the existing 3036 DB. All the circuits are doubled up in fuse holders anyway and i want to leave that board well alone.


I'm gonna put a new 2 way DB in to feed this radial.

The existing board is fed in 25mm tails straight from meter.

Main fuse is 80amp, so i want to use 16mm tails as they will fit into a tiny DB a lot easier. Also 25mm is blatant overkill for a 2 way DB.

Only thing is, i would need to cut into these 25mm tails to add a DP Henley block and then have 16mm tails coming off of the Henley block to the new DB.

Is it ok to use 16mm tails when taking a feed from a Henley block fed in 25mm tails?


No 'I hope you're Part P registered and are going to declare this work' replies please. I'm a big fully qualified boy.

Thanks.

 

[telectrix]

nothing wrong with what you intend, IMO.

 

[Miketwinny]

I`d do it.

 

[Guitarist]

As long as the load and OCPD in your new CU cannot exceed the capacity of your 16mm tails then you'll be fine, regardless of what your main fuse is (as long as it's within 3M of the supply)
As you will need to get your DNO to pop the fuse for this work, it may be worth getting them to simply fit an isolator, then you can do it all at your leisure.
Finally, as you are part P registered, it's always nice and easy to put questions like this to your scheme provider. A quick 2 minute phone call is always preferable to waiting around for an answer in here.

 

[GLENNSPARK]

As long as the load and OCPD in your new CU cannot exceed the capacity of your 16mm tails then you'll be fine, regardless of what your main fuse is (as long as it's within 3M of the supply)
As you will need to get your DNO to pop the fuse for this work, it may be worth getting them to simply fit an isolator, then you can do it all at your leisure.
Finally, as you are part P registered, it's always nice and easy to put questions like this to your scheme provider. A quick 2 minute phone call is always preferable to waiting around for an answer in here.

oh come on!!...lol...

 

[polo1]

What's the incoming supply - TNS, TNC-S?

Regards

 

[Guitarist]

oh come on!!...lol...

Do you not bother then?

 

[stuartcourt]

I always allow 3 days on a board change for DNO, you cant put a price on safety :drool5:

 

[SPARTYKUS]

I usually do a risk assessment and find the DNO weren't needed.

Don Logan? Wouldn't want to get on wrong side of you I might find you stamping on my head when in bed in Spain.

 

[Guest55]

Do you not bother then?

i think we all know the answer to that lol.
same answer as mine.
;-)

 

[GLENNSPARK]

Do you not bother then?

what...bullin the bullit...or ringing the DNO?...lol..

 

[GLENNSPARK]

if you ring the DNO...alls you get is some stupid, obnoxious bint on the end of the phone anyway who knows f**kall...

 

[Guitarist]

if you ring the DNO...alls you get is some stupid, obnoxious bint on the end of the phone anyway who knows f**kall...

Never had a problem with UKPN. Guess it depends on your area.

 

[MDJ]

No 'I hope you're Part P registered and are going to declare this work' replies please. I'm a big fully qualified boy.

Thanks.

well then you should know the answer, an apprentice could answer this with a belly full of beer on board, come on man get a grip, what do you think :rofl:

 

[Mr.Si]

Never had a problem with UKPN. Guess it depends on your area.

If you call edf, they pass you to someone else, who passes you back to edf who passes you back again. And so it goes until the day you die... Because neither of them deal with this sort of thing.

 

[GLENNSPARK]

Never had a problem with UKPN. Guess it depends on your area.

oh...were all like that round here....
thats why i fit in so smoothly....

 

[D Skelton]

What size are your MCBs in the new 2 way? If for example a 20A and a 6A there'd be nowt wrong with 4mm tails for your supply

Personally, I'd say even 16mm for a little 2 way is overkill (depending on circumstances obviously).

 

[don Logan]

well then you should know the answer, an apprentice could answer this with a belly full of beer on board, come on man get a grip, what do you think :rofl:

I think yeah it's fine. But then I think of all the naysayers that might start saying that you can't mix conductor sizes without fusing down, even in a Henley block.

So I thought I'd ask. Seems a pretty valid question to me.