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3 Pin Charger Tripping House

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Hi,

Newbie owner (this lunchtime from Dartford). My home charger isn’t being installed until later in the week, so I thought I’d top up the charge I used returning home using the 3 pin plug adapter provided.

I’ve tried two different plugs in the house (not using extension leads)... but they trip the entire house every time the car starts to charge. In car shows it’s tempting to be at 5amp..... feel like I’m missing something stupid.

(am in east Anglia, so super charger’s are mythical beasts I’ll discover on holiday).

Help!
 
Will try - thanks. I’ve just managed to get some in using polar....so that’s an option until ops point arrives.

Evidently the problem could lie in the car, the UMC, or your house wiring. If your Polar charge was AC rather than CCS, that makes it less likely (but not impossible) that it's the car. As you seem to be saying that this happens a few seconds into the charge (UMC has gone 'click' and the car is gradually ramping up the current when it fails), that suggests probably not the UMC.

So my suspicion is that it's your house that has the problem. Two likely causes:
  • You've got other appliances leaking to earth, either legitimately (loads of them leaking a tiny amount, like if you have a room full of PCs), or due to a minor defect (like damp got into a heating element) such that the RCD in your house is "right on the edge", and adding the car tips it over.
  • There's an earth-to-neutral fault somewhere on the same circuit (or one of the other circuits protected by the same RCD). Since earth and neutral are at 'almost' the same voltage, this type of fault is invisible under normal conditions, however when the current gets big enough the neutral voltage starts to diverge and the fault is detected.
These faults are a bugger to find, as the problem could be anywhere in the fixed wiring, or in an appliance plugged in anywhere in the house.

One thing you could try is plugging in to the same socket(s) something other than the car with a similar 10A load (try a kettle if yours is reasonably high wattage, or a big electric heater). If that makes it trip, you've proved the problem isn't in the car (and is almost certainly option 2 above). If not, I'd start by trying the car + UMC anywhere else (ie. not at home) that you can try a 13A socket without causing embarasment if it trips, just to rule out car faults.

However, if you are getting a dedicated chargepoint soon then that will probably clarify things (though don't be totally surprised if you then find that the car sits there charging perfectly on its dedicated circuit while causing the RCD to trip everything else in the house).
 
You've got other appliances leaking to earth, either legitimately (loads of them leaking a tiny amount, like if you have a room full of PCs), or due to a minor defect (like damp got into a heating element) such that the RCD in your house is "right on the edge", and adding the car tips it over.

I've got exactly the same problem - but thanks to your insight I managed to get it working. Turn off everything else in the house, started charging, ramped up to 10A, then turned everything else in the house back on, one at a time. Everything's working happily now.

Of course if I press the 'stop charging' button then it trips the RCD again. But at least I've got a temporary solution to get me through the next 10 days until my Rolec charger gets installed!

We'll see where we are when that gets up and running...
 
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I've got exactly the same problem too. Picked up my M3 in Birmingham today (great experience), but it only had enough charge to get me home with about 30 miles to spare. Not a problem I thought, as I'd just charge it up at home - but I've tried a few sockets and it trips my main RCD every time.

I've now driven to an office building I have access to, and it's charging quite happily (slowly!) from there - I'm going to wait until I've got enough charge to get me to the Grantham superchargers, and top up there - it's going to be a late night!

PodPoint install not until 7th Oct, so I could really do with working out what's causing the RCD to trip.
 
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I've got exactly the same problem too. Picked up my M3 in Birmingham today (great experience), but it only had enough charge to get me home with about 30 miles to spare. Not a problem I thought, as I'd just charge it up at home - but I've tried a few sockets and it trips my main RCD every time.

I've now driven to an office building I have access to, and it's charging quite happily (slowly!) from there - I'm going to wait until I've got enough charge to get me to the Grantham superchargers, and top up there - it's going to be a late night!

PodPoint install not until 7th Oct, so I could really do with working out what's causing the RCD to trip.
Made it to Grantham with 8 miles to spare!
 

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Polar charge was ccs, so I guess that doesn’t rule the car out. I *think* the car was charging on type 2 rather than ccs at Dartford on collection (charger didn’t have the “bottom 2 pin section” from memory)

I’ll try the option of having everything off in the morning and having another go. Dedicated is supposed to be installed on Monday, but I’d like to be sure the 3 pin can work for emergencies on the road.

really do appreciate the detailed and helpful replies.
 
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I have the same problem. I have tried the 2 nearest Polar 3 pin chargers (each 25 miles away!) but both are US. Neighbours are understandably reluctant to let me plug in a potentially US piece of kit. Anderson charge point on order but not due delivery until end Nov.
 
I have the same problem. I have tried the 2 nearest Polar 3 pin chargers (each 25 miles away!) but both are US. Neighbours are understandably reluctant to let me plug in a potentially US piece of kit. Anderson charge point on order but not due delivery until end Nov.
Try turning off everything in your house by switching off all breakers except the one feeding the socket you use for charging. If this is on the same circuit as other sockets (eg all downstairs sockets) unplug everything on this circuit.
Then plug in your UMC and try charging. If this works by itself then start switching everything else back on and and plugging in one by one until it trips again.
It could be the fault is accumulative across many appliances / outlets. Often described as an earth leakage build up by electricians. Hard to trace but the solution is to separate up the circuits onto multiple RCBOs (breakers). When you have your charger installed they will put it on a separate breaker anyway but until then you may need to switch off and unplug other appliances in the house.
 
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Thanks for the help & advice on here - I've discovered that if I turn the breaker for the induction hob off, and unplug the tumble dryer (even though neither of them were actually switched on), then I'm able to charge the car without the main RCD tripping. Once the charging starts, I can turn everything else back on without a problem. This evening we've had the hob, both ovens, and tumble dryer all running while the car was charging without an issue - just seems to be the intial action of starting the charge that's causing the RCD to trip.
 
Perhaps you could try setting the UMC charge to less Amps when you initially start charging with it, then gradually increase up to 10A?

The one time we visited someone and tripped the whole of their house trying to do a 13 AMP charge that didn't help. We moved from Garage 13AMP (which might have been excusable as "dubious wiring") to a socket right next to the distribution board, and dialled down to minimum AMPs (5AMPS I think?) Same thing.

I didn't think to try "everything off" in the house, to see if that sorted it. I did tell me friend that he needed a Sparky to check his house wiring, but I think he thought it unnecessary (even though we then plugged in at his neighbour and charged just fine there). Thankfully neighbour was an obliging car-nut, albeit new to EV :)
 
Perhaps you could try setting the UMC charge to less Amps when you initially start charging with it, then gradually increase up to 10A? Maybe that would save you having to switch off everything in the house, start charging the car, and then switch the house equipment on one by one?

How do you do that? I can't recall seeing any settings until you try and start charging, which by the time you can jump in, the RCD will have tripped. iirc I did see it greyed out at 5A. And of course, RCD is nothing to do with current overload so I am not optimistic, but will try.
 
Weirdly since the first day my UMC seems to start and stop charging now with no issues without having to turn everything off first. Very odd. Looking forward to Rolec install next week as I haven't managed to get to a full charge since saturday night (after a visit to a supercharger!)
 
Weirdly since the first day my UMC seems to start and stop charging now with no issues without having to turn everything off first

I am guessing, but maybe something you unplugged you have plugged back in with better connection.

After house was rewired here there was a fault and after some diagnostics was isolated to a single strand of a single cable into a single 13 AMP socket that was not "captured" in the fitting, and making contact with the Earth. needed Netter eyes than mine to see it!
 
I’ll see if I can pinpoint fault in my own time then depending on what it is, get some else involved.

I’m curious if inline RCD in new extension cable I am waiting will trip before rest of house. That will make me more comfortable when I need to hook up elsewhere where tripping an RCD would not go down so well. I suspect it will end up as either no or random.