Energy Supplier can't install an EV Charger

[Firegod]

Hi all

Looking for some clarification and perhaps just santiy check my this please.

I went through the online application process with Ovo, gave them all the pictures and diagrams. We have the main electric meter in the house along with an isolation switch, and a consumer board. The consumer unit has a main 100A fuse. The mains in fuse on the supply is 60A. We have underground armoured cable going from the electricity meter to power the shed. In the shed is a new consumer unit, meeting the 18th Edition Amendment 2 specs. It has a 100A main fuse with 4 x Type B RCBOs (1 x 6A, 1 x 16A, 1 x 32A & 1 x 40A). We want the EV charger installed on the side of the shed, connected back to the 40A RCBO. Will take 2-3m of cable to attach it up. Sadly, Ovo won't do this and can only install the EV Charger routing back to the main consumer unit in the house. Which to me seems odd.

Nevertheless, I plan to go ahead and buy the same compatible charger which I was going to get through Ovo (Hypervolt 3 model) so that I can use it with their cheaper EV tarrif. I'll obviously need a 3rd party electrician to come and install it. Is that acceptable? Would any electrician be able to do this or do I need a specialist?

The person I spoke with at Ovo said that the installer then contacts the DNO and does a "connect and notify" (is that the correct terminology?) to tell them about the charger. I asked what happens with the 60A main fuse, and they said the main consumer unit in the house didn't look too busy and so 60A would probably be fine but that the installer could "clamp the charger to a 60A limit". Is that something installers do and would know about?

Thanks for any help.

 

[b0rn2sk8]

I think the issue is your asking a big box installer to do an installation that is not ‘normal’. You may be better off using a local electrician, however most EV charger manufacturers want you to use someone off their list who has done their training.

Whether you can attach a charger to the remote consumer unit is how big that armoured cable is. It should also have some kind of fuse and RCD at the meter end.

Your 60A main fuse may be a problem. It’s not about how many circuits you have in a consumer unit, it’s what it attached to those circuits. An electrician will need to do a maximum load test to make sure you don’t blow the 60A cut out. The DNO is likely to want to upgrade it.

Many chargers, including the hypervolt can be configured with an ‘adaptive fuse’ so they ramp down if the total load is approaching the 60A limit. However this needs a hardwired CT clamp and is usually ran in external CAT5/6 cable. The DNO may mandate this if you are on a looped supply which is likely if it’s only 60A. Other chargers offer wireless CTs (Zappi comes to mind).

Your focused on Ovo, have you considered another supplier that may offer a better tariff for your needs? That may also change the charge point you want to use. Ovo only gives you cheap electricity for your car where as someone like Octopus gives you cheap electric for your whole house when the car is charging. Rates might look higher but you only need to load shift a surprisingly small amount of usage into the cheap period to be better off.

 

[Firegod]

I think the issue is your asking a big box installer to do an installation that is not ‘normal’. You may be better off using a local electrician, however most EV charger manufacturers want you to use someone off their list who has done their training.

Whether you can attach a charger to the remote consumer unit is how big that armoured cable is. It should also have some kind of fuse and RCD at the meter end.

Your 60A main fuse may be a problem. It’s not about how many circuits you have in a consumer unit, it’s what it attached to those circuits. An electrician will need to do a maximum load test to make sure you don’t blow the 60A cut out. The DNO is likely to want to upgrade it.

Many chargers, including the hypervolt can be configured with an ‘adaptive fuse’ so they ramp down if the total load is approaching the 60A limit. However this needs a hardwired CT clamp and is usually ran in external CAT5/6 cable. The DNO may mandate this if you are on a looped supply which is likely if it’s only 60A. Other chargers offer wireless CTs (Zappi comes to mind).

Your focused on Ovo, have you considered another supplier that may offer a better tariff for your needs? That may also change the charge point you want to use. Ovo only gives you cheap electricity for your car where as someone like Octopus gives you cheap electric for your whole house when the car is charging. Rates might look higher but you only need to load shift a surprisingly small amount of usage into the cheap period to be better off.

Thanks. Just been reading about the ALM and CT setup on the Hypervolt. I guess it will make sense to an installer... The cat6 ethernet cable confused me! Is that just inside the unit?

I'm happy for them to do a load test and check etc but I only have one cable into the main fuse. Our property was overhauled about 20 years ago so we got rid of the loop. Probably why the fuse is 60A!

The cable to the shed is thicker than the one into the main property.

Yeah I like Ovo and just getting their smart meter as well to use with the anytime EV tarrif so will most likely stay with them.

 

[Adam_151]

The cable to the shed is thicker than the one into the main property.

The cable to the shed will be an armoured, the incomming supply is very likely to be a straight concentric and a 16mm SC can have a decepivly small overall diameter compared to armoureds!

Can you post pics of the consumer units in both the house/garage? There is no automatic reason you cant have an EVSE from a sub-board, but there are a number of things that might not be suitable on your intallation which might need sorting out (the number one being, is the submain of a suitable size?), the national installers tend to like to do a "standard install" which involves splitting the tails in the meter box and putting a separate board in. Its very much "kwik fit jobs" standard jobs done quickly, the vast majority of the time an acceptable quality but if you have special requirements they probably cant accomodate you

 

[b0rn2sk8]

Thanks. Just been reading about the ALM and CT setup on the Hypervolt. I guess it will make sense to an installer... The cat6 ethernet cable confused me! Is that just inside the unit?

The CT clamp needs to go sound your main income supply as it leaves the meter. On a hypervolt this needs to then be hardwired to the charger, usually using 1 pair from a CAT5e or CAT6 network cable. The charger also needs internet either via WiFi or hardwired again. Given it’s on a remote building, that’s something to consider.

I'm happy for them to do a load test and check etc but I only have one cable into the main fuse.

It’s a standard part of any new electrical circuit install.

Our property was overhauled about 20 years ago so we got rid of the loop. Probably why the fuse is 60A!

If you have been unlooped, the fuse may have already been upgraded but they didn’t change the sticker. When the DNO is notified, it will trigger them to check.

The cable to the shed is thicker than the one into the main property.

It will be because of the armouring, the normal meter tails are just double insulated individual conductors, the armoured cable will be double insulated, plus metal armouring plus an outer layer. As the above poster said, pictures paint a thousand words.

Yeah I like Ovo and just getting their smart meter as well to use with the anytime EV tarrif so will most likely stay with them.

The smart meter will work on any supplier (assuming it’s relatively recent) and the Octopus tariff (intelligent go) I mentioned is the same as anytime, you tell them when you want the car charged by, they charge for that time. The worst thing you can be is loyal to a supplier.

Given the more complex install you are looking at, you might be better off with something like a Zappi where you can use a wireless CT. I would suggest speaking to a charging specialist that offers a wider range of options than a cookie cutter installer like an Energy supplier. I’ve not used smart home charge but they offer a wide array of options.

The downside of the Zappi is that I don’t think Zappi supports Ovo anytime but it is supported by Octopus.

 

[jpaul]

practically - does the armoured cable have identification ?
voltage drop maybe the issue - in somewhat a similar situation, posted on before, 10yr old terraced property garage about 30-40M away has an armoured cable,
a 4mm2 cable on a 30A fuse at main box. ... but my suspicion is that with voltage drop of some 12mV/A/m ~ 14V, as 32A that would exceed 5% drop on 230V,
so charger would have to be limited at 20A/5KW or so.

 

[Firegod]

Hi all thanks for the comments. I'll do my best to reply, sorry if I miss any. I've just gone ahead with a quote through Smart Home Charge. It was nice to be able to upload a video walk through and explain as I went along. I have said that if we can't do the shed, then on the outside of the main property would be the fallback plan (i.e. normal fitment). See what comes of it.

We started work changing over the consumer unit in the shed today regardless (as it needs doing). So managed to get some pics of stuff.

Here is how the shed is fed from the main consumer unit:

Here is the full consumer unit in the house with a spare space for a 32A or 40A RCBO:

Single phase, 60A mains fuse with isolation switch:

And here is the shed sub consumer unit (current fitted one and replacement one both pictured):

Hope this is interesting or useful for some.

Cheers.

 

[Firegod]

And sorry, the mains cable in the shed. Forgot to show what that looks like more closely.

 

[Firegod]

Just bought a 100A Isolator Switch as well so that the shed can be safely disconnected from the mains supply instead of having to knock the house off. May as well get that fitted same time as the new unit in the shed!

 

[b0rn2sk8]

Is that armoured just stuffed in with the main tails? That’s ropy as ****, no offence intended if you installed it, it’s just not to code, and dangerous.

That armoured cable should be protected by an MCB/RCD or RCBO upstream at the house end. If it’s cut between the CU and the shed, you’ll have a dead short with no protection and a fire.

Either way, that cable isn’t thick enough to run a charger and the existing loads at the shed.

Call an electrician would be my advice.

 

[Adam_151]

Just bought a 100A Isolator Switch as well so that the shed can be safely disconnected from the mains supply instead of having to knock the house off. May as well get that fitted same time as the new unit in the shed!

You don't want an isolator. You need to provide over current protection for that SWA, it can't be in with the tails like that! (even if it was 25mm that would be no good) So you ideally need a switchfuse, or if you are prepared to have a lack of discrimination, a separate small consumer unit with a 40A/45A MCB (You'd need to split the tails with henleys to feed the new unit)

I can't properly get a handle on the size of the SWA, but its looking like its 6mm 3C (does it say the size on the sheath?)

 

[Adam_151]

You'll also need the EVSE supplied by an RCBO that breaks the neutral, the standard BG ones do not, but they do make some that do, they have the suffix DPA on the end of the model number instead of A. e.g. CUCRB40DPA

https://www.bgelectrical.uk/uk/fortress-cp/devices/rcbo You might have to click the "double pole, B curve" button

I'm not actually sure they are actually double pole, more likely single pole switched neutral, whereas single module RCBOs typically are single pole, solid neutral

 

[CraigN]

they wont usually touch any consumer units.

They cut the cables from the cut out/100a fuse/ meter and install connectors which connect to their own fuse. When they did mine they said they wont install any other way.

If you want it done your way you will likely have to pay for it yourself.

Edit here is how they had to do mine.

Black blocks in-between meter and consumer unit, going to their own mini consumer unit. Also had this little black cable that goes over cable from meter. He told me this detects if current draw is too high and reduces charging. Sorry im no electrician so not sure of the correct terminology.

In the end he ran a really long armoured cable from the top of their installed mini consumer unit to where i wanted the charger.

 

[Firegod]

Is that armoured just stuffed in with the main tails? That’s ropy as ****, no offence intended if you installed it, it’s just not to code, and dangerous.

That armoured cable should be protected by an MCB/RCD or RCBO upstream at the house end. If it’s cut between the CU and the shed, you’ll have a dead short with no protection and a fire.

Either way, that cable isn’t thick enough to run a charger and the existing loads at the shed.

Call an electrician would be my advice.

Had my neighbour pop round to take a look - he is an electrician. He said that it wasn't ropy doing it that way (and no I didn't do the install lol). He thinks it would potentially be OK to run the EV from the shed over that cable. But he said that the installer will come out and take a look and yeah, if shed is no good because of the cable or what have you, then we'll just fit it on the house. The armoured cable did have an RCD at the shed end if that helps and the cable was double earthed. Anyway I am certainly no expert but nice to be told that there are options at least.

You don't want an isolator. You need to provide over current protection for that SWA, it can't be in with the tails like that! (even if it was 25mm that would be no good) So you ideally need a switchfuse, or if you are prepared to have a lack of discrimination, a separate small consumer unit with a 40A/45A MCB (You'd need to split the tails with henleys to feed the new unit)

I can't properly get a handle on the size of the SWA, but its looking like its 6mm 3C (does it say the size on the sheath?)

Yeah my neighbour thinks it is 6mm as well.

 

[b0rn2sk8]

6mm is thick enough to run a charger but you’ll not have the head room for any other loads.

I’m afraid I disagree with your electrician friend, that is ropy.

That cable has no suitable over current protection upstream. The only thing protecting it is the DNO cut out fuse.

Also stuffing a 6mm cable in with a 16/25mm cable is just asking for a fire created by a poor connection, particularly if you are putting an EV charger on it.

Neither is acceptable IMO.

 

[Firegod]

6mm is thick enough to run a charger but you’ll not have the head room for any other loads.

I’m afraid I disagree with your electrician friend, that is ropy.

That cable has no suitable over current protection upstream. The only thing protecting it is the DNO cut out fuse.

Also stuffing a 6mm cable in with a 16/25mm cable is just asking for a fire created by a poor connection, particularly if you are putting an EV charger on it.

Neither is acceptable IMO.

Cheers. Yeah the dno fuse is the only thing. I'll see what the installer comes back with.

 

[jpaul]

you haven't got an unused 50A? breaker at the end of the consumer unit ?

e: but ok my consumer unit has two rccb's so a trip doesn't take out whole house, one including feeding garage

 

[b0rn2sk8]

40A maximum for 6MM.

 

[ZG002]

Had my neighbour pop round to take a look - he is an electrician. He said that it wasn't ropy doing it that way (and no I didn't do the install lol). He thinks it would potentially be OK to run the EV from the shed over that cable. But he said that the installer will come out and take a look and yeah, if shed is no good because of the cable or what have you, then we'll just fit it on the house. The armoured cable did have an RCD at the shed end if that helps and the cable was double earthed. Anyway I am certainly no expert but nice to be told that there are options at least.

Yeah my neighbour thinks it is 6mm as well.

You sure he's an electrician?

Running the submain out of the bottom of the main switch like that is terrible. The 6mm (it's defo 6mm) isn't correctly protected at all.

It's current carrying capacity is about 53a and should be protected by a suitable over current protection device (it's easy to sort)

There is enough headroom on the cable to deal with a ev charger but it doesn't give a lot of room for anything else to be run at the same time in the shed.

None of the main ev companies, ovo, ohme etc will touch it. You will need to get a private electrical contractor who are ev charger trained to install one. (I'd suggest not asking your neighbour)

 

[Firegod]

Thanks all been reading about the Henley blocks and what not. Think I'll try and return that new consumer unit in shed. If the 6mm cable needs a 40/45a mcb then this one has a 100a mains fuse. That's a bit silly!

Quick question. If we split with the Henley blocks, obviously the live neutral out to the shed where the new isolator and unit is fitted, will be the 6mm cable. Will that go into the block OK?