AC Charging issue - but I don't think it's the dreaded CCU

[QLeo]

Goth Leo our SE LR has developed an odd issue which we're trying to narrow down at the moment. The issue suggests it's the dreaded CCU problem, but there's a chance it's our cable.
We've not had any issues in over 2 years with the car. It's the generation that can do 3-phase charging, and we often use the 22kW pillar in the village. In February, we successfully used a 7kW pillar overnight across in the east in Dornoch.
A couple of weeks back, I was back in Dornoch, and again had reason to overnight. We plugged the car in to the same pillars as in February. Everything looked hunky-dory but when I checked on the app an hour or so later, the charge had stopped. We tried 3 other plugs in that cluster, but all exhibited the same issue.

On our return, knowing the CCU issue, I plugged in to the 22kW pillar. It charged without a problem for nearly 2 hours, which was all the time I had.

Yesterday we were in Inverness, and after a DC charge (which has always worked, by the way) we'd done a bit of ferrying around, so thought we'd park at a 7kW pillar while we went for a walk to add a few more percent. Two pillars failed to connect. The third connected, but stopped after perhaps 2%.

So it looks as though whatever the problem is is restricted to 7kW and/or single phase charging. I guess the next step is to try a different cable, as it is possible, I suppose (clutches straw) that it's our cable.

I can't tell from reading some of the many threads on the CCU issue whether it is restricted to single phase/7kW operation, given that 3-phase charging seems to work. It looks as though this may be the case but I can't find an example of someone reporting this.

But I would appreciate any comments, on my logic or on my straw clutch.

 

[Anon70]

Have you checked the settings for AC current and what does the info button report?

Watch from timestamp 9:30 in this video

 

[QLeo]

Have you checked the settings for AC current and what does the info button report?

Watch from timestamp 9:30 in this video

Thanks for that. I haven't changed any of those settings but will check them.
A neighbour who has a 7kW charger has kindly offered a charge to help determine the fault. They also have spare cables, which could be handy. In the meantime, I'll check those settings.

 

[Rolfe]

I've been wondering if Goth Leo would get the CCU problem eventually. At least if it is that we now know the fix and you have a good dealer.

 

[QLeo]

I've been wondering if Goth Leo would get the CCU problem eventually. At least if it is that we now know the fix and you have a good dealer.

You follow all the permutations and variations of this issue - do you think this is showing all the signs? I'm confused by the fact that it seems happy with 3-phase power.

 

[Rolfe]

I really don't know. This isn't a point I remember anyone else raising. But I don't think you should rule it out.

 

[QLeo]

I really don't know. This isn't a point I remember anyone else raising. But I don't think you should rule it out.

Thanks.

 

[QLeo]

OK, the plot thickens, but everything now points to using the 3-phase cable on a single phase (7kW) charger.
Our neighbour's Zappi connected quickly and easily using the tethered cable. I left the car charging for 1.5 hours without any issues. It suggests, unless it's a really random problem, that it may not be the CCU, but could be our cable.
In further extreme neighbourliness, they've lent us a 7kW cable they don't need. We'll try this on Saturday when we know we'll be at a 7kW pillar for the day.
It would be interesting to understand exactly how a 3-phase cable works on a single-phase connection, and indeed, whether duff cables are a thing.

 

[tsedge]

Good luck investigating. I must admit I hadn't heard of cars having single phase problems but still charging on three phase AC. Of course it is possible, I suppose. DC charging should be unaffected however as it bypasses most of the CCU.

Do a comprehensive set of checks with different equipment to prove that there is a problem with the car. Remember this fault - if it exists - tends to get worse relatively quickly, shortening the period the car will charge for.

 

[QLeo]

Good luck investigating. I must admit I hadn't heard of cars having single phase problems but still charging on three phase AC. Of course it is possible, I suppose. DC charging should be unaffected however as it bypasses most of the CCU.

Do a comprehensive set of checks with different equipment to prove that there is a problem with the car. Remember this fault - if it exists - tends to get worse relatively quickly, shortening the period the car will charge for.

That's helpful, thanks. Good that you've not heard of cars having single phase issues but OK on 3 phase, as that points to the cable too. I've been wondering if I should give the garage a pre-confirmed-problem call, but I'll hope for the best for the mo.

 

[tsedge]

That's helpful, thanks. Good that you've not heard of cars having single phase issues but OK on 3 phase, as that points to the cable too. I've been wondering if I should give the garage a pre-confirmed-problem call, but I'll hope for the best for the mo.

When you go to the garage they need to be able to quickly reproduce the problem and not put it down to user error. For that, you need to be able to demonstrate it happening quickly and furnish them with your tests (preferably in writing) to show that you know what you are doing and they need to take it seriously. Too many garages will just throw in on charge for 10 minutes and declare the car working.

 

[QLeo]

When you go to the garage they need to be able to quickly reproduce the problem and not put it down to user error. For that, you need to be able to demonstrate it happening quickly and furnish them with your tests (preferably in writing) to show that you know what you are doing and they need to take it seriously. Too many garages will just throw in on charge for 10 minutes and declare the car working.

Good advice, thanks.

 

[Martinonline]

Do you know what power you were receiving from the 22kW EVSE? I wonder if it is possible that the car charger can cope with just 2 phases if the EVSE does not trip on an unbalanced load. That would mean reduced power to the car compared to the normal 3 phase level.

 

[QLeo]

Do you know what power you were receiving from the 22kW EVSE? I wonder if it is possible that the car charger can cope with just 2 phases if the EVSE does not trip on an unbalanced load. That would mean reduced power to the car compared to the normal 3 phase level.

That's a smart observation. But it was the usual ~11kW on 3-phase. I think I need to do as many chargers on AC as possible over the next little while to get some better data

 

[QLeo]

Right, to update those who have been helping me get to the bottom of this issue, today I used a borrowed single-phase cable and charged on a Chargeplace Scotland pillar. Unlike the initial experiences, at 4 (or maybe 5) different pillars at 2 locations, when our normal 3-phase simply would either not start a charge or start briefly, then fail, this simply worked exactly as expected, from 24% to 100%. I should have tried the 3-phase cable midway to see for sure if it has developed a problem on single phase, but didn't have the opportunity, and, to be honest, wanted to see if the charge would complete.
So, so far, I'd say it does point to the cable, which is quite a relief. But again, if my logic is flawed, or there's a different way of seeing this behaviour, do please comment.

 

[OriginalBigAl]

Have you tried putting a Multimeter on the 3 phase cable to check continuity along each of the 5 internal wires , to see if one is faulty. Also check for resistance ( there should be some ) between the CP pin and earth. The resistance value is what the car uses to recognise what cable is plugged in.
Try borrowing another 3 phase cable to compare values and see if that charges correctly.

 

[QLeo]

Have you tried putting a Multimeter on the 3 phase cable to check continuity along each of the 5 internal wires , to see if one is faulty. Also check for resistance ( there should be some ) between the CP pin and earth. The resistance value is what the car uses to recognise what cable is plugged in.
Try borrowing another 3 phase cable to compare values and see if that charges correctly.

Thanks for those ideas. The problem is, as described originally, the 3-phase cable works perfectly on a 3-phase pillar, and it seems somewhat unpredictable (charging starts, but then stops a few minutes later). It's just on single-phase pillars we have had the problem. I'm not sure how to check single-phase connectivity on a 3-phase cable. @Martinonline sensibly suggested checking whether the expected output was achieved on 3 phases, which, if not, would indicate one of the phases had an issue, but I'm getting the expect 9.6kW or so as measured on iSmart.

I think I'll keep tabs on this over time, and hang on to the borrowed single-phase cable for a while. It's all very odd. But I'll do a continuity check to see if anything obvious comes up. If anyone has ideas about how a 3-phase cable connects to a single-phase pillar, I'd be grateful.

 

[OriginalBigAl]

Mines a 11kw charger and the cable that came with the car from MG was of 22kw capacity . I'm assuming yours is the same. I am of the understanding that on single phase 7kw charging only 1 phase is used at 32a ( 6mm cable ) plus the neutral and earth , so your car would charge at 6.6 kw using two of its three chargers . If however you have the 11kw cable then you would only get 3.3 kw using one of the internal chargers. As before the resistance value of the cable is detected by the car and it will only draw the current that that resistance value allows.
A single phase cable , 7kw 32a 6mm should have the same resistance value as a 22kw 3 phase one, if you have both then you could compare that , Ohm ... CP to earth pin/ hole. on the car side.
11kw cable different value and granny cable different again.

 

[QLeo]

Mines a 11kw charger and the cable that came with the car from MG was of 22kw capacity . I'm assuming yours is the same. I am of the understanding that on single phase 7kw charging only 1 phase is used at 32a ( 6mm cable ) plus the neutral and earth , so your car would charge at 6.6 kw using two of its three chargers . If however you have the 11kw cable then you would only get 3.3 kw using one of the internal chargers. As before the resistance value of the cable is detected by the car and it will only draw the current that that resistance value allows.
A single phase cable , 7kw 32a 6mm should have the same resistance value as a 22kw 3 phase one, if you have both then you could compare that , Ohm ... CP to earth pin/ hole. on the car side.
11kw cable different value and granny cable different again.

Er, I think I follow that! It's not an MG-supplied cable as at the time they would only provide 7kW cables, and as the car could handle 11kW 3-phase, we bought an aftermarket one.

Do you have any idea which phase (ie, which 'ole?) is used when the 3-phase cable is used on a single phase pillar?

Ta for the additional info.

 

[OriginalBigAl]

Not a clue! I thought mine were marked up ph1, ph2 ph3 in faintly embossed markings , but its a bit dark now to go and check. Which ole is live on the single phase , ie not blanked, its likely its the same on the 3 phase cable for single phase charging, but I did not say that. This message will self destruct in 20 seconds.