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recoveringacademic

CU: where to install it / them ?

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Sid - from British Gas-  came to see me  today. And a very nice man he was. Didn't charge a penny.

 

This is what he left me..... and now a bit like @nod on this thread

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I need to decide on which CU to  buy. Or CUs ? - There's the question

 

This installation is in our piggery, some 5 meters from our house. The piggery act as our rubbish store,  laundry room and will have the socket which powers the digester, some soffit lights, some lights of its own, a small under sink water heater, and a few sockets. In essence our piggery is the same as most people's garage (but no pig - or car for that matter)

 

Never one to keep it simple if I can possibly make it complex, I'm thinking that the piggery should (must?) have its own CU perhaps? With a separate one inside the utility room in the house.

 

The house is five meters away, and we've already laid the electricity duct between the house and the piggery.

 

Simple question. One CU or two? More? And, if you are feeling kind, please explain why. Thanks

 

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Two CUs without doubt.

 

The piggery has too many potential circuits to do otherwise. I'd go:

 

Lights

Sockets 

Water Heater

Digester

 

You'd get a compact SBS board in there along with Henley blocks to feed the main CU in the house I reckon.

 

This is a 180x180x98 6-way SBS board, all RCBO for a job where there was no space. I put Dave at SBS onto this enclosure. Just to show how compact things can get.  Obviously insulated enclosure as was a while ago. 

 

post-22030-0-92928700-1406215824_thumb.jpg.f329eba342672ff843fe740fcc949f1c.jpg

 

post-22030-0-18758600-1406215931_thumb.jpg.8ce043898db286435c8171a02d377a80.jpg

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My vote would be a switch fuse in the meter box to feed the house, and a CU inside the piggery for it's own stuff. Keep the piggery CU within 3 metres of the meter box to prevent that too needing it's own switch fuse (i.e just put it on the inside of the wall backing on to the meter box)

 

So out of isolator into a pair of henley blocks, from those to the switch fuse with one pair of tails and through the wall into the piggery with the other.

 

By the way, is that one of those smart meter thingies? Did you choose that or was it forced upon you?

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Just re-read the 5m as in >3m! :ph34r:

 

Is this literally inside the piggery or outside on an outside wall?

Edited by Onoff

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Before replying, it's brilliant to have you two on this forum. Thanks @ProDave and @Onoff

1 hour ago, Onoff said:

Is this literally inside the piggery or outside on an outside wall?

 

One gable end has been partly removed and so is open to the elements: that's where the bins and meter box are,  still covered by the roof .  Its a bit like a large sentry box. The meter is in an external meter box on the inside of the 'sentry box' wall. 

 

 Like this..... (meter box not illustrated because its hidden by the bins)

5a257b21ce318_Screenshot2017-12-04at16_41_57.thumb.png.d002221023b4085114747ccb80fae7d7.png

 

1 hour ago, ProDave said:

By the way, is that one of those smart meter thingies? Did you choose that or was it forced upon you?

 

Yes, it is the back end of a smart meter; and I have been given the gubbins for use inside the house.  I remember reading (you perhaps?) outlining why they aren't all that good an idea.

 

But the whole job was free, so maybe I cannot moan too much.......

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Just for my own education...

 

Can you put the Henley block before a pair of isolators (one per CU) or must it go after an isolator?

 

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1 hour ago, Temp said:

Just for my own education...

 

Can you put the Henley block before a pair of isolators (one per CU) or must it go after an isolator?

 

 

You could fit Henleys before (with seals of course), it is done. They are fit for purpose.

 

Now though, it's after the event so to speak, you would have to cut THEIR, the DNO/supplier's seal on the REC2. Some use numbered seals & record, some don't.

 

You'll have isolation anyway at each cu via the DP switch in each.

 

One REC2 is fine. Another is just more terminals to go loose!

 

It'll be a pain to go out to the bin store and reset something so as @ProDave says put cu inside.

 

 

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We decided to have a second panel that split the power between the two buildings as there was not room in the meter panel for the distribution switches (IMO) it could have been squeezed in but the switch fuse idea that @ProDave suggests might not make it into your box either. So our meter panel looks a bit likes yours but without the very smart meter and the second panel distributes the power to the main house CU and the garden room CU in your case you could substitute the piggery CU for the garden room.

 

 

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PS the excel panel (will eventually) provides a few additional outputs including the garden lighting, a car charger point and a local commando socket for outdoor power.

 

 

Edited by MikeSharp01
Add PS

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