What will SSEN let me get away with?

[dnb]

And will it fit anyway? I am about to start on the 1st fix wiring with a bit of help. I have a strong desire to limit the number of holes drilled through the walls (why do some electricians seem to want to turn a house into a collinder if you leave them alone? ? ), so I would like to optimise some bits of the design if I can. The first thing I'm not 100% sure about is the garage sub main.  The equipment it needs is well discussed here but am not sure how tightly the SSEN follow the "meter box is MINE" rule or the physical sizes of some of the modern parts - I would hope they are smaller than in the clockwork meter era...

 

I would like to create a sub main for the garage. It makes no sense to not do this given the equipment I intend to have in there. I don't want this sub main to enter the house - it's just additional holes and lots of copper conductor making losses for what to me looks like no good reason. So is there room in a standard meter box for the main fuse, meter, isolator, henley blocks and a switch fuse for the garage sub-main, and will the SSEN be excessively cross with me for taking up their space? I believe it will need an S type RCD as well as being SWA because we currently believe the installation can only have a TT earth. I am also told that the sub main might not need a main switch if there's a 100A switch already in place post meter, pre-henley block as SSEN seem to do these days, so RCD and breaker should be OK - not sure about this myself but if it's OK then I will go with it. The tails to the house don't need to be SWA because the CU will be on the other side of the wall within 3m and the tails won't be hidden by anything less deep than 50mm so that's less of a problem.

 

My other option is a separate box of some kind next to the meter box but this is a bit annoying because it starts to get in the way of other things and will look a bit untidy, but if it's the only way then we just have to live with it.

 

[ProDave]

You solve all these problems by having the supply routed into the garage, have as much switchgear as you want in there, to feed whatever you want, and then one submain from there to feed the house.

 

As for electricians turning your house into a collander, design it properly with a service void on the inside of the sealed envelope and you keep a nice air tight house.

[joe90]

42 minutes ago, ProDave said:

You solve all these problems by having the supply routed into the garage, have as much switchgear as you want in there, to feed whatever you want, and then one submain from there to feed the house.

That’s what I did, mainly because I wanted the meter box there and not on my “chocolate box cottage” and I mounted the temp supply box on a post next to the garage and when the garage was built swung it into the garage myself so did not have to pay fir it’s move to the permanent location. 

Edited January 21, 2021 by joe90

[dnb]

51 minutes ago, ProDave said:

ou solve all these problems by having the supply routed into the garage,

 

I would do this but for the fact the garage is a muddy hole in the ground right now. I can't really afford to build it until we have moved in to the new house and sold the current one.

[dnb]

53 minutes ago, ProDave said:

As for electricians turning your house into a collander, design it properly with a service void on the inside of the sealed envelope and you keep a nice air tight house.

 

Already done, but it doesn't help with the wife's desire for Blackpool level of outside lights!

[joe90]

2 minutes ago, dnb said:

 

I would do this but for the fact the garage is a muddy hole in the ground right now. I can't really afford to build it until we have moved in to the new house and sold the current one.

See my post above, you could still have a temporary meter box on a post with cable into the house and swing the meter box into the garage when it’s eventually built.

[dnb]

Not sure I have space to do this without making a menace for deliveries. But I would need to pay for a meter move to move the meter from its current location on the boundary to the house, so if I put SWA to the house from the boundary boxes (I have two - one for me and one for "them")  I delay that particular cost, and the move can be part of commissioning the garage. 

 

Good call...  I knew there would be a good answer here. Sometimes you need to take a step back and think about the whole problem, not just finishing the house.

 

Edited January 21, 2021 by dnb

[Onoff]

42 minutes ago, dnb said:

 

Already done, but it doesn't help with the wife's desire for Blackpool level of outside lights!

 

One of things I love about the IoW. Pitch black at night whilst driving for the most part.....not anymore!

[dnb]

14 minutes ago, Onoff said:

One of things I love about the IoW. Pitch black at night whilst driving for the most part

Me too. And the general lawlessness of West Wight.

 

I will be reining in the illuminations as much as I can. They will upset the garden owl population.

[ProDave]

9 hours ago, dnb said:

Not sure I have space to do this without making a menace for deliveries. But I would need to pay for a meter move to move the meter from its current location on the boundary to the house,

 

 

Then do as several of us have done, leave your meter box on the boundary and run TWO submains from there, one to the house and one to the garage when it is built.

[dnb]

34 minutes ago, ProDave said:

Then do as several of us have done, leave your meter box on the boundary and run TWO submains from there, one to the house and one to the garage when it is built.

I don't particularly like the meter box at the boundary long term - it becomes another badly built structure in a hostile environment to maintain - so am happy (as much as one can be) to pay the cost of getting the meter moved from the boundary at some point.

 

Delaying this cost is useful in the immediate future, but getting out of paying it at all is not part of the motivation. Sorry if this wasn't clear.

[Thorfun]

1 hour ago, ProDave said:

Then do as several of us have done, leave your meter box on the boundary and run TWO submains from there, one to the house and one to the garage when it is built.

 

Hi Dave. this is what I'm planning on doing but can I ask why one would want to run separate submains to the house AND the garage? I do have an EV so I'm thinking that a separate fusebox in the garage which can just deal with the car(s) would be useful, and also if we want extra external power in the future it would be easier to run from the garage rather than from the plant room in the basement. Are those reasons enough? or is there a technical reason to do so to split the load or whatever? 

 

I then have to figure out how Solar PV would fit in to the whole design if there are 2 separate fuse boxes and how I would feed the main house and the EVs with Solar PV. but I guess that's a whole other threads worth of questions!