Do we have 3-phase supply or not?
Discussion
Many years ago, our then electrician had made a comment that we had 3-phase supply and that one day it would come in handy. Many years after that, we had a SMETS2 smart meter fitted, and I'd completely forgotten about that innocuous remark from almost a decade earlier. Now though, I think that it might be quite significant: if we really do have 3-phase supply, it'd be perfect to be able to install a 22kW home charger for the amount of driving I would need to do with an electric car - office is 270 mile round trip away, occasionally do it in a single day, sometimes on back-to-back days so a 7kW charger would struggle to get enough juice in. I do each 132 mile leg in one go without a break in 2 hours and 15-30 minutes so don't need a break to charge, and chargers aren't always available at destination. At the moment, BEV would be difficult to live with, but a 22kW charger would be transformative.
This is what it currently looks like:
Unfortunately, even if we do have 3-phase, the smart meter only seems to be connected up to a single phase, but at least I can argue for a change with OVO if I know that they all they need to do is replace the meter rather than run in a new supply, especially if I can argue they should've left the old meter alone until 3-phase smart meters were available (if that was what we had, I haven't got a clue what we had before).
So, what the hell have we got supply wise - single phase, 2-phase or 3-phase?
Thanks in advance!
This is what it currently looks like:
Unfortunately, even if we do have 3-phase, the smart meter only seems to be connected up to a single phase, but at least I can argue for a change with OVO if I know that they all they need to do is replace the meter rather than run in a new supply, especially if I can argue they should've left the old meter alone until 3-phase smart meters were available (if that was what we had, I haven't got a clue what we had before).
So, what the hell have we got supply wise - single phase, 2-phase or 3-phase?
Thanks in advance!
Looks like you have something which isn’t one phase that’s for sure. What’s confusing is you should have three supply fuses for three phase (I’m guessing this is why you say two), it looks like a brown cable has been used for the neutral but that in and of itself is a bit weird
I would give your DNO a call in the first instance and ask them to confirm.
I would give your DNO a call in the first instance and ask them to confirm.
You have a Single Phase PME supply with a 100 Amp main incoming fuse. PME means that you only have two wires coming into your house: Live and a combined Neutral/Earth conductor. It’s odd that a brown insulated cable has been used for the later.
I suspect that this was originally a 60 or 80 Amp supply and the middle brown wire is no longer connected to the supply.
As it was inspected relatively recently by Maintenance Services Electrical Ltd, perhaps they can let you have a copy of the Electrical Installation Inspection Certificate? That would detail the nature of your electrical supply.
I suspect that this was originally a 60 or 80 Amp supply and the middle brown wire is no longer connected to the supply.
As it was inspected relatively recently by Maintenance Services Electrical Ltd, perhaps they can let you have a copy of the Electrical Installation Inspection Certificate? That would detail the nature of your electrical supply.
As above i am thinking split phase.
Whereabouts are you? You dont need to be too specific but historically again as above the south west would do them but east mids no chance really.
Sadly i suspect if you have split phase there will be no 3 phase transformer nearby meaning the likelihood of you getting 3 phase is minimal without significant outlay (think a good 5 figures).
Whereabouts are you? You dont need to be too specific but historically again as above the south west would do them but east mids no chance really.
Sadly i suspect if you have split phase there will be no 3 phase transformer nearby meaning the likelihood of you getting 3 phase is minimal without significant outlay (think a good 5 figures).
Pheo said:
Looks like you have something which isn’t one phase that’s for sure. What’s confusing is you should have three supply fuses for three phase (I’m guessing this is why you say two), it looks like a brown cable has been used for the neutral but that in and of itself is a bit weird
I would give your DNO a call in the first instance and ask them to confirm.
brown used for neutral is indeed odd - is even allowed without any marking or at least some sleeving to aid clarity.I would give your DNO a call in the first instance and ask them to confirm.
Just call your DNO? I've had 3 phase installed at home(cost £800ish). Even with a 22kw charger, lots of cars wont' take that, you'll get 11kw as an average. however it does mean '50mph' charging at home. with a 22kw capable car, that'd be 100mph! which is quicker than some chargers at forecourts etc.
I have 2 x 22kW chargers, I very rarely use either of them at 22kW but when you do need to, it's very handy indeed.
The most common situation was topping two cars simultaneously at 11kW each and being able to maximise the import during off peak windows.
All whilst running other loads too like charging a battery, heating water and so on, without breaching any limits or fuses.
It's ended up being quite a handy thing to have.
The most common situation was topping two cars simultaneously at 11kW each and being able to maximise the import during off peak windows.
All whilst running other loads too like charging a battery, heating water and so on, without breaching any limits or fuses.
It's ended up being quite a handy thing to have.
You have 2 different phases or live supplies known as split phase coming in and 1 neutral
The black fuse holders are the main incoming live feeds in old terms 3 phase was
red yellow blue now its black blue grey
3 phase would be 3 fuse units as posted in the picture above
but you are only using 1 phase of the system
The black fuse holders are the main incoming live feeds in old terms 3 phase was
red yellow blue now its black blue grey
3 phase would be 3 fuse units as posted in the picture above
but you are only using 1 phase of the system
Thank you very much for the comments gents.
Do I need to ask OVO which is our supplier, or do I need to ask our DNO which is National Grid East?
glad somebody did!
Sheetmaself said:
As above i am thinking split phase.
Whereabouts are you? You dont need to be too specific but historically again as above the south west would do them but east mids no chance really.
Sadly i suspect if you have split phase there will be no 3 phase transformer nearby meaning the likelihood of you getting 3 phase is minimal without significant outlay (think a good 5 figures).
I'm in Northampton, in the north of the county in a tiny village. I guess that rules out 3-phase for a reasonable cost. Whereabouts are you? You dont need to be too specific but historically again as above the south west would do them but east mids no chance really.
Sadly i suspect if you have split phase there will be no 3 phase transformer nearby meaning the likelihood of you getting 3 phase is minimal without significant outlay (think a good 5 figures).
Do I need to ask OVO which is our supplier, or do I need to ask our DNO which is National Grid East?
MadCaptainJack said:
QuickQuack said:
a 22kW charger would be transformative.
I see what you did there. glad somebody did! x type said:
You have 2 different phases or live supplies known as split phase coming in and 1 neutral
The black fuse holders are the main incoming live feeds in old terms 3 phase was
red yellow blue now its black blue grey
3 phase would be 3 fuse units as posted in the picture above
but you are only using 1 phase of the system
Right, that makes sense, thank you. The black fuse holders are the main incoming live feeds in old terms 3 phase was
red yellow blue now its black blue grey
3 phase would be 3 fuse units as posted in the picture above
but you are only using 1 phase of the system
QuickQuack said:
Thank you very much for the comments gents.
Do I need to ask OVO which is our supplier, or do I need to ask our DNO which is National Grid East?
It might not be as bad as you think. Sheetmaself said:
As above i am thinking split phase.
Whereabouts are you? You dont need to be too specific but historically again as above the south west would do them but east mids no chance really.
Sadly i suspect if you have split phase there will be no 3 phase transformer nearby meaning the likelihood of you getting 3 phase is minimal without significant outlay (think a good 5 figures).
I'm in Northampton, in the north of the county in a tiny village. I guess that rules out 3-phase for a reasonable cost. Whereabouts are you? You dont need to be too specific but historically again as above the south west would do them but east mids no chance really.
Sadly i suspect if you have split phase there will be no 3 phase transformer nearby meaning the likelihood of you getting 3 phase is minimal without significant outlay (think a good 5 figures).
Do I need to ask OVO which is our supplier, or do I need to ask our DNO which is National Grid East?
I have an old split phase at home, same as you only one phase is being used.
Have recently been quoted a couple of grand to upgrade to three phase (a huge difference from a few years ago when they advised it would be 10x that). Not sure if the mood has changed with DNOs and 3ph, but it’s a huge drop in price.
We’re about to get a three phase connection, our DNO is UK Power networks who have been very easy to deal with. There is a pole on the boundary of our property which has a three phase supply on it, the cost to connect to that supply and run a cable down the poll to a meter box which is 1m from the poll is £1500. We then have to get the single phase supply disconnected which is more significant as it is overhead to the house and is across a couple of poles. Total cost is £4500.
I’m told that’s “quite cheap” There’s then costs of trenching, new three phase board in the house and a new meter cupboard near on a concrete plinth where the three phase is being connected to.
Needs must though, moving the house to ASHP etc
I’m told that’s “quite cheap” There’s then costs of trenching, new three phase board in the house and a new meter cupboard near on a concrete plinth where the three phase is being connected to.
Needs must though, moving the house to ASHP etc
Connection to three phase happened this week…felt like a bit of a circus at times if I am honest. We had UK Power Networks with us on four different days and Scottish Power on another day to connect/install the meter. On one day we had seven people from UKPN on site all in their own vehicles ! Three connection the 3P three disconnecting the single phase and a supervisor!
LooneyTunes said:
Out of curiosity, did you have to arrange the meter change or did the DNO work with your supplier on this?
Also, how long was the power off for? Assume it wasn’t off for days?
Just curious as my 3 phase order is progressing so keen to make sure we’ve got everything boxed off.
Totally up to me to arrange the meter change. Much easer to arrange the switch to three phase than it is to book a meter installation !Also, how long was the power off for? Assume it wasn’t off for days?
Just curious as my 3 phase order is progressing so keen to make sure we’ve got everything boxed off.
I am currently with Scottish Power as a utility provider, I was going to move to Octopus a few months ago until I asked about three phase meter installation “we don’t have any availability for six months”. I checked with Scottish Power and was told they could install at three weeks notice.
Long story short I got dates from DNO (UK Power Networks) and then spoke to Scottish Power who having previously told me they would have decent flexibility with three weeks notice gave me only one date in September.
We ended up being without power for two days, not a disaster as we are currently out of the house.
Don’t under estimate the amount of work your electrician will have to do in the house, they will have to install a new board I imagine which is a big job in itself. Our three phase board is about twice the size of the previous one and the cable is pretty hefty. Electrician was in the house for two days over the weekend doing prep work, part of that time the power would have been off too.
To add to this.
The electrician certainly will have to do his work with the supply isolated, but there is no need to be off supply from the DNO completing their worn and the new 3Q meter being fitted.
The DNO can leave you with a 3Q cut out where one Q has fuses and the other two are blanked without fuses (make them leave the fuses onsite) they can then wire into the 1Q meter leaving you on supply until your supplier switched the meter and installs the two fuses left onsite.
One thing to note is that for Domestic properties a lot of DNO’s will fuse 1Q supplies at 80A but 3Q supplies at 3 x 60A.
The electrician certainly will have to do his work with the supply isolated, but there is no need to be off supply from the DNO completing their worn and the new 3Q meter being fitted.
The DNO can leave you with a 3Q cut out where one Q has fuses and the other two are blanked without fuses (make them leave the fuses onsite) they can then wire into the 1Q meter leaving you on supply until your supplier switched the meter and installs the two fuses left onsite.
One thing to note is that for Domestic properties a lot of DNO’s will fuse 1Q supplies at 80A but 3Q supplies at 3 x 60A.
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