EV Charger Install

[caveman2]

Enquiring for a friend as to issues re. EV Charger install. As he has an all electric kitchen ie. dish washer, induction hob, washing machine etc. and only a 60A main fuse. He realises that his DNO will need to fit a 100A main fuse.
Before he books an electrician, he intends to contact UK Power Networks. Will they be able to furnish information re. whether he has a looped service and if his power cable is greater than 16mm to allow them to fit the increased rating fuse. If they give him the positive information required and agree to fit one. What apart from the fuse change do they do on attendance. Do they inspect existing wiring & bonding and do they ask for certificates.
The 100A fuse seems necessary as a 150 mile recharge will be required every night and a 3.7kW charger wouldn't be man enough
Any help/ advice appreciated.

 

[Murdochcat]

I would say he needs a local spark first. The DNO aren’t interested in anything past the main fuse. Eyes on site are best rather than internet based guesses / opinions

Ps as for looped supplies - unless checks are made on the adjacent homes nobody knows

 

[cjcoffin]

He may be able to tell by looking if he has a looped service as there would be two cables going into the supply head but as @Murdochcat says it might be looped elsewhere. Look on the UKPN web site, they will probably do a visit f.o.c. to upgrade the fuse on the spot if it is possible, most incoming cables will take it without problem. If there are 16sq mm meter tails he will have to upgrade them at his own expense first but they might be willing to fit an 80A fuse. Unless anything looks really ropey they will not concern themselves overmuch with his side of the installation.

FWIW I have 16 sq mm tails so I had WPD out to check and it was already an 80A fuse (18.4 kW max). On that basis I have successfully applied for both a 7kW EVCS (zappi) and 5.3 kW(e) HP (Vaillant 12kW), I also have a Victron inverter system that takes 4kW to charge the batteries on E7. The zappi will control the car charging rate to ensure the 80A is not exceeded e.g. if we run the dishwasher/washing m/c on top of everything else. IMO you only need 100A if you have electric heating or an extremely big house.

 

[ericmark]

Most consumer units rated at 100 amp, the old Wylex fuse box was 60 amp which is why there are so many 60 amp supplies as fuse box has been upgraded to a consumer unit without any upgrade in the DNO fuse, however the CU total is 100 amp, so where you have a battery or solar panels, it may be over 100 amp to the CU so extra fuse needs fitting, and if the DNO fuse needs pulling to do an upgrade, better done before the DNO visit is no new seals are broken. Same with fitting tails big enough, and tiding anything which may mean DNO refuse to fit new fuse.

I would agree with @cjcoffin likely you don't need 100 amp, 7 kW = 30.5 amp, I have a three story house with a 60 amp fuse, electric showers, and since I have solar I have a record of what power used when, going back for months, in the main the power used is under 1 kW = 4.4 amps with peaks at 10 kW = 44 amp, and the car charger will auto turn down during the peaks.

Going back to a day where there are high peaks, this is my usage SOC = state of charge for my battery, biggest power use in my house is likely the freezers, we have 5 running at the moment, we really need to empty some and turn them off.

 

[caveman2]

Thanks for the advice/ info. I think that covers the questions and I'll pass it on. Many thanks again.

 

[flameport]

He realises that his DNO will need to fit a 100A main fuse.

Unlikely.

As he has an all electric kitchen ie. dish washer, induction hob, washing machine etc.

Most of which won't be in use when the vehicle is charging overnight.

The 100A fuse seems necessary as a 150 mile recharge will be required every night

While not impossible, that represents an excessive amount of driving.

 

[cjcoffin]

if the DNO fuse needs pulling to do an upgrade, better done before the DNO visit is no new seals are broken

DNOs are increasingly taking a severe line about electricians pulling their main fuse so he may not want to do it. I fitted an isolator so I didn't have to in future, worth thinking of this while you are at it.

 

[Murdochcat]

DNOs are increasingly taking a severe line about electricians pulling their main fuse so he may not want to do it. I fitted an isolator so I didn't have to in future, worth thinking of this while you are at it.

Nonsense. What makes you say that?

I’m on a job where the overhead cable has been replaced by one underground. I was onsite when the change was made and as the guys left I asked what the supply fuse was

Their answer was take a look, it’s not sealed.

 

[securespark]

I used to be well known at Norweb in the 80s and 90s. I would ring them up and give them the address and leave a form for them and they would visit and seal up the cutout I had opened to do the board change.

I did have the seals and a crimper, but they preferred me to leave it to them to seal up.

 

[ericmark]

DNOs are increasingly taking a severe line about electricians pulling their main fuse so he may not want to do it. I fitted an isolator so I didn't have to in future, worth thinking of this while you are at it.

It was at one time that the DNO had to provide an isolator, and many felt two wrongs made a right, if no isolator fitted they must expect the fuse to be pulled, however it has never really been permitted, just a blind eye turned.

advanced metering infrastructure (AMI) differs from automatic meter reading (AMR) in that it enables two-way communication between the meter and the supplier. smart meters usually involve real-time or near real-time sensors, power outage notification, and power quality monitoring.

I asked about this when mine was fitted, and the guy said it did not give power outage notification, he said it did not have a battery so not possible, however watching YouTube it seems some do, I have an isolator so does not worry me, however one can see why the DNO would not like it if they do get power outage notification.

Maybe it varies area to area, until my smart meter was fitted I noted there were no seals, been here four years and never been any seals until smart meter was fitted.

The guy did say that is all they do, no other repairs, he was not permitted to upgrade fuse, however I am now sure it is 60 amp, that's not just what it says on a sticker. It did result in longer tails, so the CT's are better spaced, I do wonder how long he had been fitting meters as he did not know the CT's had to go the right way around. However until I had problems and read the instructions, I did not realise there could be a problem if two CT coils are too close.

 

[plugwash]

Many EV chargers have a "grid limit" feature. A CT is placed on the main incoming tail and connected (either directly by wires or via a wireless transmitter unit) to the EV charger. The EV charger then monitors what is being drawn from the grid and adjusts the charge rate accordingly.