3 phase power.

[Paul Y]

We have 3 phase power into our home and at some time there was 3PH into the garage.

It would appear that the only thing left of the garage installation is a single plug - no wiring and now separate meter.

Question is who can I get to reinstate the installation? Had a look on the web and seen some horrendous pricing but think that is actually installing 3ph from scratch rather than 'just' running a cable from the house to the garage.

Or do I just get an inverter for £150 and don't worry about it?

Always interested to hear from the great and the good.

P.

[marinanut]

Depends on what you want to run on 3-ph. There are some cracking inverter drives nowadays but they can get heavy with input amperages.

[Paul Y]

Planning ahead - Band saw, lathe, welder etc.

Not looking to have them running all at the same time. We have enough power coming into the property (The comment from a sparky upon seeing our 'control cupboard' was are you running a power station?) which makes me think that longer term getting actual 3ph into the garage would be the sensible option, just not at multi thousands of pounds.

P.

[kelvfoozinda]

Do you have a picture of the incomer at the property, distribution board etc? Is there a distribution board in the garage too? I was an Electrician once and can probably talk you through what you have if its useful.

[Phil H]

If it's already got 3 phase into your house and the other side of a meter (i.e. into a dis board) it's literally running a piece of SWA cable to a local board. Any half decent electrician should be able to do it.

[Paul Y]

No distribution board in the garage or any wiring - has all been removed at some point or might not even existed. All the proof I have of 3ph in the garage is one socket.

The pictures are what is in the 'control cupboard'

P.

[gtviva]

Get some pictures up of the existing fuse board/meter & incomer and we can all put our thoughts in print!

There seems to be a few of us retired electricians hanging about!

That was quick you beat me to it! the picture links don't seem to work?

[Paul Y]

Sorry about that - Apple pictures not compatible with uploading - had to convert them to jpeg

Should be able to see it all now.

P.

[Phil H]

That "looks" like a lot of single phase breakers - do they all do something?... It looks like a very "vintage" board though.

[gtviva]

Yuk, crabtree c50 series! can you get any more pictures a bit further back showing a wider view?

[kelvfoozinda]

Plenty of C50's on ebay....
www.ebay.co.uk/itm/Crabtree-C50-MCB-30-Amp-Type-2-30A-Triple-Pole-3-Phase-Breaker/293441131132?epid=2255355838&hash=item445274527c:g:bwAAAOSwXiVeKy94

As gtviva says, a picture further back would be good to know how the meter/tails are setup.

[Paul Y]

Does this help??

P.

[henspeed]

aye thats 3 phases all right.
As others have said you just need a spare 3 phase way in your distribution board and bobs your uncle, run a 5 core out to the garage in SWA and fit a small 3phase board out there.
Shouldnt be an expensive job, any decent sparky could do it for you, but choose carefully as many domestic type ones will not be familiar with 3 phase.

Out of interest why is your house hooked up with 3 phase?

[slater]

Just get electricians round to quote. It wont be cheap. Nothing is, but if you don't understand what your looking at then don't mess with it.

Hardest part is running the cable so if you offered to do that yourself it may help the price significantly.

[homersimpson]

Before worrying about the garage I would get that fuse board changed, the old C50 range have been out of production for donkeys years and those MCB's may not even work now in the event of fault.

I also don't think that you can get a three phase supply from that type of board as its three single phase boards strapped together so if you did try and take three phase from it you would have a breaker in each section to pick up each phase and an overload on one phase would cause just that phase to drop out which isn't ideal.

On top of that you have no RCD protection which you will need in the garage and these days should really have in a house.

Any idea why the house is three phase? I've only ever seen this used on domestic installations in huge mansion houses.

[henspeed]

the two SWA's running out of the board look pretty chunky are they 5 core.
Do you actually have anything in the properly that needs 3phase currently?
If it were me, id swap the board out for something like this

Hager 3ph board

populated with modern switchgear, the installation as is looks like a bit of a mess.
Do you live in en old hotel or something that you need so many circuits, looks like 36 single phase circuits at the moment which is way more than your average dwelling.

[gtviva]

Typical electricity board couldn't even fit the main fuses straight!

As stated above get it all torn out and a new 3 phase distribution board fitted, it will take up much less space and stop your big house burning down!

Please don't take it the wrong way but if I was still in the game I wouldn't touch anything in that property without recommending changing the board first, if that didn't happen its walk away time unfortunately

[Paul Y]

Mar 12, 2020 17:17:10 GMT henspeed said:

Out of interest why is your house hooked up with 3 phase?

Not really sure TBH. Was told many years ago that it was because we are very rural and it is easier to provide a stable supply with 3ph - probably plums but our nearest neighbour, about 1/2mile away across the fields also has 3ph so might be some truth in the matter.

As an edit:-

I bought our home 20 years ago with the intention of a complete refurb - without wanting to send like an - it is very very big but was very very cheap. Started the refurb, long story short - got ripped off by practically everybody that walked through the door, wasted a fortune, my business went pop in 2008 (surprise) and only now getting to the point where we can even consider starting again on the refurb.

Had all the electrics tested and signed off as part of our insurance policy so whilst it is old it all works, trips out when it is supposed too etc. Never take any advice from people that actually do the job the wrong way!

There is a separate 'modern' fuse panel that looks after the refurbed part of the house so it is not all as bad as you would think...

Think I will just end up with an inverter.

P.

[henspeed]

it wont be expensive
In reality, the main board needs changing out regardless of what you do, its just very old and past it, so swallow that cost up.
After that dunning 3phase out to your garage is a doddle.
What I would do is find out your largest load you will run out there (assuming that it will only be run on its own) say its a lathe at 10A per phase, allow a few more amps for your lighting, heater, radio etc. Lets double it to be safe.
So we are looking at a 20A 3 Phase supply to your garage.
A 5 core 6mm2 is good for circa 56A, so id look at a cable of around that size to a 6 or 8 way board in your garage, then break out all the individual supplies from there, 3 phase MCCB in your shiny new house board of 50A, into the garage board incomer then away you go.

[henspeed]

if you are confident the board is tested etc and all good then take a 3 phase supply for your house to the garage, if no spare ways then take a 100A feed from the main incomer (use a JB and then you need to run same size cable as the incomer to the new garage DB.

I wouldnt go the inverter route when you have 3ph there, it seems madness.

I wish I had a 3ph supply