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Discussion Starter · #41 ·
Hmm, I think a new B32 MCB plus a switchable 16/30A setting will do nicely for the next few weeks, until I get my Arduino controller sorted. Then I'll allow the car to max out at 31.5A when I'm in a rush to get the final 20% in after a slow overnight 80% charge.
 

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I had a faulty mcb feeding my Chargemaster wall unit. It started tripping after an hour or so when charging at max 7kW. I verified from my Octopus smart meter readings that it was taking no more than 7kW then phoned Chargemaster as it was still under warranty. They replace it and it’s been fine since.
 

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Spec is 230 +/-10% so anything from 207 to 253 is acceptable.
Not quite. From 1 January 2004 the UK LV single phase mains supply is 230V (-6%, +10%), or 216.2 - 253.0V.

Prior to European harmonization it was 240V (-6%, +6%), so they basically increased the + tolerance so DNOs didn't have to go and tweak everything. (240 +6% = 254.4, 230 +6% = 243.8)
Since we were set up for 240V -6% there wasn't much chance of any existing UK system hitting 230V -6%, so dropping the lower limit wasn't really a problem.
 

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My charger has a readout on it, my 40 Leaf has never drawn more than 27.5A
Have you checked the pilot signal to see how much current the EVSE is actually advertising though ?

Some "32 amp" EVSE's only advertise 30 amps so naturally the car will draw less in that situation.

Unless you check the pilot signal to see what the EVSE is truly advertising you can't be sure whether the limit is the car or the EVSE.

Not saying this is necessarily the case here but it's something to consider.
 

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Mine is regularly 245v. I only live a couple of hundred yards from the substation but that still looks like 240 nominal.
On the one occasion when we did have freakishly high voltage, I discovered the hard way that my Peugeot Ion refused to charge above 247 volts. A bit of a problem when the UK mains voltage is allowed to go as high as 253 volts...
 

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Not quite. From 1 January 2004 the UK LV single phase mains supply is 230V (-6%, +10%), or 216.2 - 253.0V.

Prior to European harmonization it was 240V (-6%, +6%), so they basically increased the + tolerance so DNOs didn't have to go and tweak everything. (240 +6% = 254.4, 230 +6% = 243.8)
Since we were set up for 240V -6% there wasn't much chance of any existing UK system hitting 230V -6%, so dropping the lower limit wasn't really a problem.
In my view the EU harmonisation at 230V was just a frig of tolerances. The UK, which was previously on 240V (+/- 6%) was given a tolerance of +10%/-6% on 230V, and the continental countries that previously had a nominal 220V supply were given a tolerance of +6%/-10% on 230v. This meant that as long as new equipment could operate over the whole 230V +/-10% voltage range it could safely be used anywhere in Europe without any problems.

On the one occasion when we did have freakishly high voltage, I discovered the hard way that my Peugeot Ion refused to charge above 247 volts. A bit of a problem when the UK mains voltage is allowed to go as high as 253 volts...
Living near to a rural substation, I regularly get the supply voltage above 250V (250.9V at the moment) so I need to know to avoid the Peugeot Ion. If it goes below 240V I suspect Western Power have a problem.
 

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On the one occasion when we did have freakishly high voltage, I discovered the hard way that my Peugeot Ion refused to charge above 247 volts. A bit of a problem when the UK mains voltage is allowed to go as high as 253 volts...
The Twizy did this but was a lot more tolerant. 252 volt caused it to shut off.
 

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Discussion Starter · #49 ·
Thread drift steered back on course! Thx Jrtev, this is what I was wondering, namely if can safely put a B40 in. I've disconnected the entire mini CU at the I asume Henley blocks, using 1000V insulating gloves + leather welding gauntlets on top, so everything's 100% isolated, old B32 now out. The wire from the mini-CU to EVSE on other side of dble gge is marked 2x6 + 2.5 so I assume that's 6 sq mm on the Line & Neutral. for a cylinder that's 2.76mm dia, and I calipered it at 3mm. Is it ok to stick a B40 on this wire? Everything else around (apart from contactor inside EVSE) is labelled at 40A.

Next qn; this grey Pvc cable 2x6 + 2.5 into the MCB wasn't ferruled. Just twisted, and the single screw was as usual splaying out the strands, so I'm not happy with this local reduction in cross-section where this mess happens. Is there a standard ferruling crimper I can get from local Elec depot to do this? I have several top-quality Hellermann ratchet crimping tools inherited from deceased electrician, which look ok to me about the right size; they'll squash a ferrule into a slightly-rounded flattened-hexagon shape; one that looks too big has blue handle grips, smaller one has green grips & looks about right. The jaws of these are in 2 sections, appx 1/3 of the lengh seems like it'll clamp tighter maybe.

So, can I use these tools and are ferrules standard? Advice gratefully received!
 

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Only way of truly knowing is doing a cable calc but really I would stick with a new 32 amp. Your new works certificate should state that is what was originally fitted.
As to the crimps do you have crimping pliers with red blue and yellow jaw sets? These are most common use with yellow crimps.
 

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6mm is plenty unless your cable is (very) long run. Ferrels in a CU is overkill, I've never seen it nor been asked by Napit or Niceic to do it.

ElectricIan is right about the cert and you've done your calcs but I know some cars are pulling 34 amps and are having nuisance tripping on a b32.

Personally I prefer to fit a DBL pole RCBO b40, so it's a dedicated cu and no one can jump off it.
 

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Discussion Starter · #52 ·
My crimping tools look like this, I think pre-dates colour codes?
HELLERMANN HAND CRIMPING TOOL MK3 / 2TF | eBay

I'm not going to mess with the single/double pole-ness of this unit, so I'll swap like-with-like. Also not happy about close-ness of my Ev's 31.5 A to the 32A limit, especially as thermal derating above 30C seems to be knocking an amp or 2 off the top limit. So I'm going to get a B40, not a B32. I can see the CU getting a bit warmer in summer as ambient goes up 10C from now, which is only going to make a B32 more marginal.

My take on this is that the current's never going to exceed 32A with this Ev, unless something's gone badly wrong in which case it's going to surge up towards 40+ in no time at all, and trips all over the place will be going off. No way is it likely to sit at say a steady 38 Amps burning stuff without the current varying pretty damn quick, surely?

Oh, and maybe ferruling isn't needed officially, but I'd rather not have those loose ends splaying. I'll see what I can get hold of. And if I can't get ferrules, it's getting some 3.0mm i.d. thinwall brass tube around it, which I just happen to have around...
 

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Oh, and maybe ferruling isn't needed officially, but I'd rather not have those loose ends splaying.
A decent unit will have clamps rather than a bare screw, so that shouldn't be a problem. In fact it will be designed to clamp bare wire properly if untwisted and torqued correctly. Using a ferrule may actually be worse as you will increase the contact points.
 

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Discussion Starter · #54 ·
Yup, it has square clamper. Ok, I'll not ferrule this then! Do I need a torque screwdriver?
 

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Next qn; this grey Pvc cable 2x6 + 2.5 into the MCB wasn't ferruled. Just twisted, and the single screw was as usual splaying out the strands, so I'm not happy with this local reduction in cross-section where this mess happens. Is there a standard ferruling crimper I can get from local Elec depot to do this? I have several top-quality Hellermann ratchet crimping tools inherited from deceased electrician, which look ok to me about the right size; they'll squash a ferrule into a slightly-rounded flattened-hexagon shape; one that looks too big has blue handle grips, smaller one has green grips & looks about right. The jaws of these are in 2 sections, appx 1/3 of the lengh seems like it'll clamp tighter maybe.

So, can I use these tools and are ferrules standard? Advice gratefully received!
You can use the thin-walled bootlace ferrules without a crimper - srewing the terminal down will squish it enough.
 

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My crimping tools look like this, I think pre-dates colour codes?
HELLERMANN HAND CRIMPING TOOL MK3 / 2TF | eBay

I'm not going to mess with the single/double pole-ness of this unit, so I'll swap like-with-like. Also not happy about close-ness of my Ev's 31.5 A to the 32A limit, especially as thermal derating above 30C seems to be knocking an amp or 2 off the top limit. So I'm going to get a B40, not a B32. I can see the CU getting a bit warmer in summer as ambient goes up 10C from now, which is only going to make a B32 more marginal.

My take on this is that the current's never going to exceed 32A with this Ev, unless something's gone badly wrong in which case it's going to surge up towards 40+ in no time at all, and trips all over the place will be going off. No way is it likely to sit at say a steady 38 Amps burning stuff without the current varying pretty damn quick, surely?

Oh, and maybe ferruling isn't needed officially, but I'd rather not have those loose ends splaying. I'll see what I can get hold of. And if I can't get ferrules, it's getting some 3.0mm i.d. thinwall brass tube around it, which I just happen to have around...
Don't overly stress this. If you look at the diameter of good old 30 amp fuse wire which took something like 45 amp then consider the contact area of the 6mm in the terminal you will appreciate what I mean.
Make a good termination and forget about it.
 
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My crimping tools look like this, I think pre-dates colour codes?
HELLERMANN HAND CRIMPING TOOL MK3 / 2TF | eBay

I'm not going to mess with the single/double pole-ness of this unit, so I'll swap like-with-like. Also not happy about close-ness of my Ev's 31.5 A to the 32A limit, especially as thermal derating above 30C seems to be knocking an amp or 2 off the top limit. So I'm going to get a B40, not a B32. I can see the CU getting a bit warmer in summer as ambient goes up 10C from now, which is only going to make a B32 more marginal.

My take on this is that the current's never going to exceed 32A with this Ev, unless something's gone badly wrong in which case it's going to surge up towards 40+ in no time at all, and trips all over the place will be going off. No way is it likely to sit at say a steady 38 Amps burning stuff without the current varying pretty damn quick, surely?

Oh, and maybe ferruling isn't needed officially, but I'd rather not have those loose ends splaying. I'll see what I can get hold of. And if I can't get ferrules, it's getting some 3.0mm i.d. thinwall brass tube around it, which I just happen to have around...
Don't overly stress this. If you look at the diameter of good old 30 amp fuse wire which took something like 45 amp then consider the contact area of the 6mm in the terminal you will appreciate what I mean.
Make a good termination and forget about it.
 

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Another thing worth mentioning, is that your RCD is a typeA RCD. It needs to be changed asap to a TypeB RCD, that will last longer and no risk of damaging it with DC leakage. A type A RCD cannot handle DC leakage, only AC leakage!
 
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