new consumer unit- distance from meter

[flinty]

Hi,
I want to know if there is a maximum distance that a consumer unit can be installed away from the meter (the property is on the Isle of Wight).
The property has an existing fuse type consumer unit (with only 3 fuse ways) in the integral garage. I want to put a new consumer unit inside the property itself but this means that the meter will be approx 5 meters from the consumer unit.
Is it acceptable to join the existing and new meter tails (from the new consumer unit) using a 100Amp Henley block, or is it best to run new tails from the new consumer unit and get the local electricity company to connect them up?

 

[equitum]

What is the size of the supply fuse, what size are the existing tails, what is the route to the new CU position (e.g. through cavity wall containg insulation, in trunking etc)

If you are unaware that these are factors to be taken into account, I suspect you would be better placed to get a qualified person to do the work as replacing a CU is not an easy underatking.

 

[flinty]

What is the size of the supply fuse, what size are the existing tails, what is the route to the new CU position (e.g. through cavity wall containg insulation, in trunking etc)

The existing main fuse is 100amp, the existing tails are 25mm, the route to the new consumer unit is to go up through the garage ceiling into the garage loft space and then through a wall with no cavity insulation and into the house itself.

I am aware of the need not to run cables through insulation and the effect of voltage drop and cable sizing when run in trunking. etc.

 

[equitum]

Should be OK, but I would protect the tails with earcthed metal trunking in the garage. Also worth checking with the DNO that the length is permissable, each DNO vary.

 

[CallEdsFirst]

I though most DNOs went for 3m?!?!?!

 

[flinty]

I will check with the DNO just to confirm. I had automatically assumed that mechanical protection for the tails was an essential.
cheers

 

[DESL]

Why not connect existing tails to a switch fuse, of appropriate rating, in garage and then split concentric from there to new CU.

 

[Pietros]

Our DNO specified 3 metres on a block of 60 flats.
They insisted on each set of tails being protected by a local 63A double pole breaker, our XLPE then went from the dp switch to the consumer unit in the flat (up to 60 metres).

 

[equitum]

I though most DNOs went for 3m?!?!?!

So you don't think they all do then ?!?!?!?!?!?!?!

 

[securespark]

My experience with UU & CN & the old SWEB was that tails of no more than 3m are allowed. Others limit to 2m.

 

[CallEdsFirst]

I though most DNOs went for 3m?!?!?!

So you don't think they all do then ?!?!?!?!?!?!?!

Errr no, neither does he:

My experience with UU & CN & the old SWEB was that tails of no more than 3m are allowed. Others limit to 2m.

What's your point?

 

[equitum]

My point was as a previously posted : DNO's vary on permitted tail lengths, and the OP should ask for their advice.

On a practical level, they seem happy enough to witness properties with inadeqaute sized tails, I can't see why they should have a major issue with 5M of 25mm tails.

 

[CallEdsFirst]

My point was as a previously posted : DNO's vary on permitted tail lengths, and the OP should ask for their advice.

I was merely suggesting that I thought a 5m limit was unlikely, 3m being the likely limit.

On a practical level, they seem happy enough to witness properties with inadeqaute sized tails, I can't see why they should have a major issue with 5M of 25mm tails.

So, practically speaking he shouldn't bother checking with the DNO because they should be ok with it? Make your mind up!

They should ask for a switchfuse if the run is longer than thay permit, as suggested. This will also be the safest surely! Isn't that what we should be advocating?[/b]

 

[equitum]

So, practically speaking he shouldn't bother checking with the DNO because they should be ok with it? Make your mind up!

I didn't say don't bother checking with the DNO. I said the opposite. You have totally misconstrued my comments which intended to point out the double standards of DNO's i.e. turn a blind eye to all sorts of bodged and unsafe existing meter tails when they or their subcontractors change meters etc, but then insist on unecessary requirements such as 2M max length for new meter tails. I appologise if my post indicated otherwise.

They should ask for a switchfuse if the run is longer than thay permit, as suggested. This will also be the safest surely! Isn't that what we should be advocating?[/b]

Yes, I agree which why i advocated contacting the DNO for advice. As there are 10 DNO's I am not in a position to know their individual requirements.

Flinty, did you get a response from the DNO ?