Power to the Garage - does this sound reasonable

Syla5 · 6 Jul 2015 at 10:46

Hi Collective.

I am looking to get power out to my gargage and have had one electrician round for a quote so far.

My initial request was to go from the main fusebox in the house, a tight route to the fusebox but something I would have expected a sparky to be comfortable doing.

After looking through the job the electrician advised that based on the loads I am looking at putting through the garage circuit he has suggested spurring off the ring main from a socket in our lounge, feeding 4mm armoured cable in to a garage consumer unit and then running a lights circuit and socket circuit in the garage.

On the current ring main I have the following:
TV
Surround Sound
Sky Box
Blue Ray player
Washing Machine
Tumble Dryer

It is a regular occurance that all can be running at the same time.

With the addition of the garage circuits the following will be added:
Room Heater (winter use of the garage)
Sterio/Ipod Dock + Speakers
LED bulbs in a light circuit - 2-6 bulbs max
fridge/freezer
Christmas lights at christmas time
Lawn mower
Power tool charger.

It will be possible that at times all of the applicances will be running on the main ring, and at least the heater, sterio, lights and fridge Freeze will be running on the additional circuit.

Is this going to put to much strain on the circuit? Should I be getting the new circuit in the garage hooked straight in to the main fuse board?

As an aside, I am getting the main fuse carrier replaced (old metal style) and the main fuse upgraded (done by UK Power networks FOC) as well as tails upgraded (Done by Npower) before the electrician comes along, as he will be upgrading the main fuseboard as the current one is old and has no RCD/MCB protection.

Bickaxe · 6 Jul 2015 at 11:02

Get a few more quotes first. Personally I would have it on a separate circuit.

We had our fuse box replaced with an MCB a couple of years ago. The new unit picked up a lot of faults that our fuse box ignored so be prepared for that.

Brutal biff · 6 Jul 2015 at 11:20

No it doesn't sound right at all if there's a fault in the garage it knock out the sockets in the house

Garage should be on its own circuit also do you have rcd protection also if it's a pme earthing you need a separate earth rod installing for the garage

Sounds like a cowboy

a1ex2001 · 6 Jul 2015 at 11:51

Brutal biff said:
No it doesn't sound right at all if there's a fault in the garage it knock out the sockets in the house

Garage should be on its own circuit also do you have rcd protection also if it's a pme earthing you need a separate earth rod installing for the garage

Sounds like a cowboy

or someone looking for a quick solution!

What he is proposing is probably within the rules and definitely safe but very far from best practice and not something I would want someone doing in my house.

Seek further quotes and specify what you want.

ZG002 · 6 Jul 2015 at 12:08

As an electrician myself, I'd just tell who ever quotes that you want a separate circuit for the garage. With all the other work you are having done the only issue could be the cable run. You might end up paying a tad more but it's worth it imo.

Syla5 · 6 Jul 2015 at 12:28

The cable run seems to be the only sticking point here really, and not something that the electrician refused to do, he merely made a suggestion based on the power draw to the garage being relatively low and the solution being sufficient to cover the requirement.

The problem is the fuse box backs on to what used to be an exterior wall, now after an extension to the rear of the property there is no quick route through the wall to get a cable from the fusebox to outside, hence the suggestion offered.

I think that if i can run a dummy cable (so that armoured cable can just be tapped to it and pulled through) just through the wall and up the gap it may just save a few ££ in electrician time and get me the solution i am looking for at just the extra cost of the additional armoured cable.

Bickaxe said:
We had our fuse box replaced with an MCB a couple of years ago. The new unit picked up a lot of faults that our fuse box ignored so be prepared for that.

The electrician did warn of this, he advised that most commonly the faults are with appliances but wiring faults are possible after the change over, so i have been warned.

Brutal biff said:
No it doesn't sound right at all if there's a fault in the garage it knock out the sockets in the house

Even if the garage has its own consumer unit? Surely a fault in the garage will trip the breaker there?

I will arrange a couple more quotes, i have some time as the fuse carrier, fuse, and tails wont be completed until 27th.

ZG002 · 6 Jul 2015 at 15:24

If its RCD protected (which it will be after board upgrade) then a fault in the garage would knock off your sockets in house also if done the way electrician mentioned. What type of floor is below the board?

I tend to recommend a electrical inspection before a board change so any nasties can be flagged up and rectified before you go to RCD protection.

Syla5 · 6 Jul 2015 at 16:28

The floor below the board is the main concrete slab for the house. The board is almost central to the house, ultimately if it was on an external wall it would have been very easy to just pop the cable through the wall and run it to the garage, that there is only a 2"-3" gap between the old exterior wall and new internal wall, and that the cable would have to be routed through this wall and then up said gap is the challenge.

My thoughts about the RCD protection are along the lines of its a necessary step forward for safety and if it’s going to throw up nasty’s I may as well just roll the dice and deal with them there an then. If I get an inspection and it shows issues I will still have to get them fixed, but would have cost me an inspection. If I get the board changed and no faults then great a little money saved, otherwise I am in the same position as if I had had an inspection.

ZG002 · 6 Jul 2015 at 16:40

It's more to do with if your socket circuit for instance has a leg that's down N-E and it will trip the RCD but a fuse will be un-effected. So electrician comes along does the board and sockets are tripping, he then spends hours trying to locate the fault. Honestly it can be a head ache, that a simple IR test before the board is replaced can flag up. Guess it's more to the electricians benefit really, but at least you know what costs etc you are likely to be facing. The installation should really be tested anyway after the new board etc is fitted as you are changing the characteristics of the supply.

I'm confused about this internal/external wall set up. But if you can get a draw cable in yourself ready then it will help lots.

HardwareGeek · 6 Jul 2015 at 16:53

Separate circuit is a better idea and put on its own rcbo or a non rcd protected mcb so it wont take out the house elecs if you get a fault in the garage, you cannot guarantee that the garage consumer unit will trip before the house etc

Plus over size the circuit as you may want more power in future and you then have spare capacity.

Sounds like you want to run the cable up a cavity which you not supposed to do so maybe that is why they guy is hesitant plus it being awkward.

PS. The Best practice would be for the spark to have done some basic testing during the quote to give an idea if you are likely to have any faults that require fixing and allow time to trace and fix them rather than be caught by surprise on the day etc

For a quote i would confirm cpc in lighting circuits and eli at suspected end of line, global ir test all circuits and individual of any low readings to give an idea of what needs looking at and continuity on all rings to give an idea if i am gonna have to trace a loose connection etc

He should also do a lot of the testing before removing the old board so you can always stop to fix the faults before putting the new board in and having trips or circuits left off and need to come back later etc

ZG002 · 6 Jul 2015 at 17:06

HardwareGeek said:
PS. The Best practice would be for the spark to have done some basic testing during the quote to give an idea if you are likely to have any faults that require fixing and allow time to trace and fix them rather than be caught by surprise on the day etc

For a quote i would confirm cpc in lighting circuits and eli at suspected end of line, global ir test all circuits and individual of any low readings to give an idea of what needs looking at and continuity on all rings to give an idea if i am gonna have to trace a loose connection etc

He should also do a lot of the testing before removing the old board so you can always stop to fix the faults before putting the new board in and having trips or circuits left off and need to come back later etc

Pretty much how I've always played it.

I've been sent to replace 3036 boards with dual RCD split load boards (TT system 16th edition days) in the past with no testing done, some times you get lucky.. Other times you find borrowed neutrals, Low N-E readings, no cpc, Undersized bonding etc etc the list goes on. Madness in my mind to leave all that to chance on the day.

Think OP intends to knock garage down in a few years if I remember from other thread?

Makhaira · 6 Jul 2015 at 19:06

Ask them to quote if you dig the trench yourself too, no point paying a tradesman for unskilled labour.

Millwall.FC · 6 Jul 2015 at 20:25

Don't know if I understood this right but he suggested spur a 4mm radial off the down stairs sockets?

ZG002 · 6 Jul 2015 at 21:18

Yep, 4mm armoured as well....

Syla5 · 6 Jul 2015 at 22:15

Yeah sort of. The circuit he suggested spurring off is only the extension socket circuit. The rest of the house is on its own circuit. So the circuit he was intending to spur off probably only has a quarter of what the remaining house circuit has on it.

From the first electrician I am getting a quote from the cost of fitting the board is all inclusive of fault finding tied in to the board replacement. The only additional costs will come is something major needs sorting.

I will be digging any trench myself, no point paying electricians to do labouring.

Yes the cable run would be up a cavity. I have an alternative route which would ultimately be boxed in as it's currently got some pipes boxed in so I would remove the current boxing in to run the cables up and in to the same loft space going through the cavity would do.

To help I will post some pictures. Some things to bare in mind. The fuse carrier, fuse, tails, and earthing are going to be replaced. All booked in and happening before any of this work takes place.

Fuse box and main supply feed under the stairs. If you look closely you can see a hole in the wood to the left of the fuse carrier there is an opportunity to remove a brick there to feed a cable up the cavity and this is what I was considering doing. Those cables you can see in that hole already feed in to sheathing.

Wider angle of fuse box location. Utility room door to the right (part of extension, used to be exterior wall of the house.)

Gap to span through to utility room and utility room boxing (just visible on the right hand side) in where cable could run

From in the extension. If the cable is run in to the utility room or up the cavity it would go in to the accessible loft space around the corner on the left, then would need to go all the way over to the right and outside and down the exterior wall, through the ground and in to the garage.

I have raised the job through rated people today and I am making enquiries with other electricians. I won't have the fuse carrier, fuse, and tails work completed until the 27th July so I have a little time.

ZG002 · 6 Jul 2015 at 22:33

I'd drill through and up that boxing if you are willing to open it up, what pipes are in there? How much room is there?

Syla5 · 6 Jul 2015 at 22:50

ZG002 said:
I'd drill through and up that boxing if you are willing to open it up, what pipes are in there? How much room is there?

At the bottom is a low height soil stack, and at the top there's just 2 copper pipes feeding in hot and cold water. Plenty of room at the top, the soil stack end though will be tight.

Syla5 · 6 Jul 2015 at 22:57

Here's a better shot of the boxing in work

ZG002 · 6 Jul 2015 at 23:51

That's the route I'd personally take from your photos. If you don't mind removing some tiles. Might be a better route somewhere, but it's hard to tell from photos.

What's on other side of the wall that toilet is attached to?

Syla5 · 7 Jul 2015 at 00:30

The lounge. The wall on the left of the last picture of the lounge is where the toilet backs on to. The wall on the left of the toilet shot is the wall behind the sofa in the lounge shot, both the utility door and lounge door as well as the fuse box are on what used to be the exterior rear wall of the house.