How common is 2-phase supply?

[NSS]

Long story short, I bought a new Volvo PHEV and it doesn't charge at the expected rate on our Zappi home charger. Volvo contend that to achieve the higher rate (6.4kW) you need a 2-phase 16amp supply.

 

My contention is not merely that the technical manual does not state this, but that single phase is the standard domestic supply in the UK so why would they quote a charge rate based on a supply type that is (at best) rare.

 

What I am struggling to identify is just how rare?

 

Any wisdom on the matter would be greatly appreciated 👍🏻. 

[-rick-]

Cars are designed for a global market. 3-phase is common in commercial charging points and homes in Europe. Most cars will charge faster when plugged into 3-phase.

 

Why they have cheaped out and only put chargers on 2-phases I'm not sure. Guess it's cost saving rather than targetting a specific market. 2-phase supplies are common in some places (notable the US - though 2-phase US can be used as single phase 240v).

 

Depending on how they wired this up internally, you may be able to supply the same phase to both internal chargers, effectively running 6.4kw single phase. IIRC a lot of modern 3 phase kit, is 3 seperate single phase supplies rather than something that requires the phase separated phases specifically.

[NSS]

1 minute ago, -rick- said:

Cars are designed for a global market. 3-phase is common in commercial charging points and homes in Europe. Most cars will charge faster when plugged into 3-phase.

 

Why they have cheaped out and only put chargers on 2-phases I'm not sure. Guess it's cost saving rather than targetting a specific market. 2-phase supplies are common in some places (notable the US - though 2-phase US can be used as single phase 240v).

 

Depending on how they wired this up internally, you may be able to supply the same phase to both internal chargers, effectively running 6.4kw single phase. IIRC a lot of modern 3 phase kit, is 3 seperate single phase supplies rather than something that requires the phase separated phases specifically.

 

Thanks for that, Rick, but what I'm trying to establish is just how rare 2-phase is in the UK? My contention is that, if it's as rare as I believe, quoting charging rates based on 2-phase is both misleading and disingenuous. 

[-rick-]

Almost non-existant here, but again I think you should think of 2-phase as 3-phase (where they aren't using the whole capacity). 3-phase charging is relatively available here but again limited at homes.

[Nickfromwales]

34 minutes ago, NSS said:

Long story short, I bought a new Volvo PHEV and it doesn't charge at the expected rate on our Zappi home charger. Volvo contend that to achieve the higher rate (6.4kW) you need a 2-phase 16amp supply.

 

My contention is not merely that the technical manual does not state this, but that single phase is the standard domestic supply in the UK so why would they quote a charge rate based on a supply type that is (at best) rare.

 

What I am struggling to identify is just how rare?

 

Any wisdom on the matter would be greatly appreciated 👍🏻. 

I’ve done a few HMO’s where 3 phase wasn’t available, so I had the DNO bring the same phase in twice; so 2x 100a supplies. 
 

Depends on how the charger uses this power, as 2 phase doesn’t make any sense at all, and as you say should be glaringly obvious in the MI’s. 
 

Can you get 3 phase and switch the zappi out for the fast charge unit? That will charge at differing rates iirc, so you don’t have to keep bashing the battery with unnecessary super-rapid charging.  

[-rick-]

1 minute ago, Nickfromwales said:

I’ve done a few HMO’s where 3 phase wasn’t available, so I had the DNO bring the same phase in twice; so 2x 100a supplies. 

 

That's not 2-phase though. Both supplies are from the same phase, if the car was relying on the phase rotation (which I very much doubt) then it wouldn't work.

[-rick-]

BTW I did quickly look at the Zappi install instructions. They appear to have phase monitoring circuitry so it wouldn't work supplying more than one phase if you didn't have a true 3 phase supply, even if the car doesn't actually need separated phases, just power supplied on multiple legs of the connection.

[NSS]

Thanks @-rick- @Nickfromwales . In the manual it simply states that the max charging rate on a home charger is 6.4kW, but in a pdf buried on their web site it states that the car has a "2 phase on board charger" and that home-charging on a single phase supply is "limited to 3.7kW"

 

 

[Nickfromwales]

1 hour ago, NSS said:

Thanks @-rick- @Nickfromwales . In the manual it simply states that the max charging rate on a home charger is 6.4kW, but in a pdf buried on their web site it states that the car has a "2 phase on board charger" and that home-charging on a single phase supply is "limited to 3.7kW"

 

 

Does it show a wiring diagram and can you give it the same phase x 2? Otherwise it seems it's looking for 415v across the two live supplies.

[NSS]

42 minutes ago, Nickfromwales said:

Does it show a wiring diagram and can you give it the same phase x 2? Otherwise it seems it's looking for 415v across the two live supplies.

No diagram, and nothing more than the statement above. I made a formal complaint to Volvo and they referred me to a document, dated November 2023, for the 2024 model and said it was the applicable document, not the one embedded in the online manual for my 2026 model and dated April 2025. They have refused my complaint and I have now complained to the Motor Ombudsman (though not holding my breathe), so am gathering evidence for that and for a potential legal action. I really don't like being taken for a fool.

Edited Monday at 23:37 by NSS

[Jonny]

I have just purchased a rural barn and am going through the utilities provision. National grid have offered me split phase (2-phase) if the single phase doesn’t suffice. Three phase is not available due to distance/cost. 
 

The farm next door is also run off of split phase 

[Big Jimbo]

@jonny I know what you mean about cost. I have 3phase to my existing bungalow. Only One phase is metered. I have permission for knocking the bungalow, and building Two new houses. I enquired about bringing in a new 3phase supply. It is in the ditch outside the front boundary, and no more than 1.5 meters from my boundary. To bring a new supply, to a new cabinet just inside my boundary, i was quoted £24k. That was with me supplying the box at the boundary. My alternative is having the existing supply split, with each new property having 100amp single phase supply, leaving the Third phase unused. Cost £2k. Each new house is going to have a single phase. Im not paying £24k. Blinking ek.

[Nickfromwales]

30 minutes ago, Jonny said:

I have just purchased a rural barn and am going through the utilities provision. National grid have offered me split phase (2-phase) if the single phase doesn’t suffice. Three phase is not available due to distance/cost. 
 

The farm next door is also run off of split phase 

Split (same) phase I assume, as we did with that HMO?

 

Defo an option if you need more juice, but a bit trickier to manage solar / export etc if you’ve 2 heads.

 

Cant recall if the dual (same) phase supply can run through a single 3 phase meter though.

 

For a new client, the DNO has just run a 1ph 95mm2 cable right to the clients back garden and then split / reduced to make that into a dual 25mm2 supply. Not metered yet so I’ll wait to see what they offer.

 

As current flows the same, I’d have thought a 3ph meter would work, anyone? 

[Nickfromwales]

19 minutes ago, Big Jimbo said:

@jonny I know what you mean about cost. I have 3phase to my existing bungalow. Only One phase is metered. I have permission for knocking the bungalow, and building Two new houses. I enquired about bringing in a new 3phase supply. It is in the ditch outside the front boundary, and no more than 1.5 meters from my boundary. To bring a new supply, to a new cabinet just inside my boundary, i was quoted £24k. That was with me supplying the box at the boundary. My alternative is having the existing supply split, with each new property having 100amp single phase supply, leaving the Third phase unused. Cost £2k. Each new house is going to have a single phase. Im not paying £24k. Blinking ek.

Is the high price due to a significant transformer upgrade having to be undertaken? 

[Big Jimbo]

@Nickfromwales No mention of the transformer. Traffic lights, blah, blah, blah, Seems a joke at £24k. The cable is at most 750mm deep. I would have paid £5k for the future proofing of Two 3phase supplies, but, £24k buys a few materials for the build.

[Nickfromwales]

22 minutes ago, Big Jimbo said:

@Nickfromwales No mention of the transformer. Traffic lights, blah, blah, blah, Seems a joke at £24k. The cable is at most 750mm deep. I would have paid £5k for the future proofing of Two 3phase supplies, but, £24k buys a few materials for the build.

Have you contested it and asked them to reconsider? 
 

Did they give you a quote which had a full breakdown, before you broke down when reading it   

[Big Jimbo]

To be honest @Nickfromwales, I told the surveyor to not even bother quoting for a new supply. I was that Peed off. The only actual quote i received was £2k for the split of the existing 3phase. 100amp for each property will be fine, even if i chuck a bit of solar on each house.

[Kelvin]

I had a similar estimate for a supply where the connecting pole was literally the other side of  our fence. I dug the trench from the pole to the kiosk. All they had to do was pull their cable and connect it. I didn’t get a sensible cost until I asked for an actual quote which was £5k. I queried that and it reduced to £2k. Then when they came to do the survey they said it would be £1k which is what they charged me. A few weeks after the install they contacted me to say that they hadn’t used half the materials they planned to use and gave me a £600 refund. 

Edited yesterday at 08:40 by Kelvin

[-rick-]

17 hours ago, NSS said:

No diagram, and nothing more than the statement above. I made a formal complaint to Volvo and they referred me to a document, dated November 2023, for the 2024 model and said it was the applicable document, not the one embedded in the online manual for my 2026 model and dated April 2025. They have refused my complaint and I have now complained to the Motor Ombudsman (though not holding my breathe), so am gathering evidence for that and for a potential legal action. I really don't like being taken for a fool.

 

Clearly you are pissed off feeling decieved (fair) but I wonder how much difference the 3.7k vs 6.4kw charging will make to you in practice. How big is the battery?

[Mr Punter]

I have a 100A single phase supply and use it for the house and to supply a twin EV charge point that will supply 2 sockets up to 7.4kW each.

 

Some of the plug in hybrids have a very small battery / electric range so they may not be optimised for quicker home charging.

[NSS]

48 minutes ago, -rick- said:

 

Clearly you are pissed off feeling decieved (fair) but I wonder how much difference the 3.7k vs 6.4kw charging will make to you in practice. How big is the battery?

 

19kWh, so 5 hours as opposed to 3.

[-rick-]

6 minutes ago, NSS said:

19kWh, so 5 hours as opposed to 3.

 

So in the vast majority of cases you will always be able to fully charge your car every day (even twice a day) without much hassle?

[SteamyTea]

10 hours ago, Jonny said:

I have just purchased a rural barn and am going through the utilities provision. National grid have offered me split phase (2-phase) if the single phase doesn’t suffice. Three phase is not available due to distance/cost. 
 

The farm next door is also run off of split phase 

Many farms I have dealt with have split phase.

 

Split phase is part of the local grid voltage balancing system, may be the same in countries that use it more i.e. USA.

 

(There is Phase voltage, L1 to N, and Line voltage L1 to L2. Line voltage is phase voltage x √3)

[NSS]

1 hour ago, -rick- said:

 

So in the vast majority of cases you will always be able to fully charge your car every day (even twice a day) without much hassle?

In theory, yes, but that's not the point. Here's the document that appears if you put my model details or reg no into Volvo support, or pull it up in the vehicle itself.

 

https://www.volvocars.com/uk/support/car/xc60-plug-in-hybrid/article/0ed816eed33d98cac0a8cc377bc12bc7-83c0c849d91ad5fac0a8cc3751bbe62b-8664b2fa77a7e089c0a8296870d1a409/

 

No mention of needing 2-phase.

 

[-rick-]

9 minutes ago, NSS said:

In theory, yes, but that's not the point.

 

Yeh I get that. Your issue comes down to not getting what you expected which is frustrating and hopefully your complaint will lead to documentation changes from Volvo, but at least you haven't been put in a situation where the vehicle just doesn't work for you.

 

The volvo docs do seem quite poor. When I first saw this thread I googled for Volvo PHEV charging and the first hit was a document that clearly covered the limitations but the document you linked to doesn't.