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Hi everyone,
I'm here to try get some help and gain some electrical understanding as we seem to be having never ending issues trying to get a 7kW charger installed to our home.

For those who find the below far too long to read, my question basically comes down to:
I thought a 7kW charger would come off a 32A RCD protector within the usual consumer unit? Is this the case or do they run higher than this? If so, what do they require, a 100A protector?

So, we applied to ChargedEV back in November to have a Smart+ meter installed to our property.
After an initial application an engineer arrived to inspect our electrical supply and said our property was looped with our neighbour and had a mains fuse which was too old to be relied upon. So Electricity NW Ltd (ENWL) would need to be contacted to install an independent connection to our neighbour, replace our fuse and install an isolation switch in order to allow our car charger installation to go ahead.
ChargedEV contacted ENWL for us and the works were prompty arranged. Luckily we got on with our neighbours very well and they agreed to the works which involved considerable disruption to their driveway.

Anyway, this was arranged and programmed in and was completed on Saturday (01st Feb). New mains lines installed, new 100A mains fuse and a new isolator switch just above it leading to our traditional electric meter.


While this was being arranged I had contacted my energy supplier (Octopus) to move over to the OctopusGO tariff. As this required a smart meter, they arranged to replace our meter on Monday after the ENWL had been completed. A rather miserable chap turned up to do this on Monday (03rd) and made no comments about anything to do with our installation. He simply installed the new electricity meter after the isolator switch. I thought this was all OK.
He then installed the gas meter and said he would have to return as the time of the day had got too late and he couldn't commission the unit.

Then the ChargedEV guy arrived today to install our charger after I believed all the required works had been completed to allow this to go ahead. He arrived and immediately informed me he still couldn't complete the work as the isolator switch is located before the meter. Meaning when he spurs off it, all the electricity would be un-metered.
He said that the smart meter installer should have identified this and moved the isolator so that it was AFTER the meter (before the consumer unit). I appreciate why he wasn't willing to do this as he isn't the supplier of the meter and they are all security protected.
I think he could see I was frustrated then so he installed the unit to the outside of the home and wired it all back to the meter cupboard ready for connection. He has left a blank trip switch box and some other gubbins in there to finish the installation after the issues he's identified have been solved.

So I had then to try and contact my supplier and the installer of the smart meter. Cutting out some long conversations, this basically means a new order with a 16day lead-in time. So this now won't be rectified until 21st and I then need to arrange to get the charger installer back to finish his installation.

So as I'm sure you can tell I'm finding this whole process rather frustrating.
[RANT]
If the Gov't want to roll out more EV's home charging is going to be a key element of this and we can't all be using granny chargers. Yet if old homes need to go through all this to get a 7kW charger installed then it will put everybody off. [/RANT]



Anyway, I thought that the charger would simply run off a 32A connection (like a cooker or shower) and so with some blanks left in our consumer unit I thought they would just install a new RCD switch in there and run a power line to the charger?



I'm wondering if anyone can help me understand why this isn't the case and why the charger can't be fed off the existing supply coming out of my new (not fully operational) smart meter before it goes into my CCU?
Or why it can't just be formed off a new RCD switch in the consumer unit?

Many thanks,
Rob
 

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Take a chill pill and dwell on the fact that you are getting your antiquated and inadequate electrical system in shape for the 20th century.

The isolation switch upstream of the supply meter is totally against Regulations so the company that installed this is required toot suite to put this right.

You are far better off keeping the electrical switchgear / protection separate to the Consumer Unit. Detailed reasons why described in various posts on this forum.
 

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In some cases you could supply an EV charge point from a 32A MCB in an existing consumer unit but it adds complexity to the install - is there space for a non-Rcd protected 32A MCB and busbar connection, or space for a type A RCD inside the board, whats the load on the existing board and can it supply an additional 32A load, can you get suitable MCBs to fit the existing CU etc etc.

Every install job becomes customised, whereas taking a separate supply from after the isolator into a dedicated mini consumer unit while not particularly neat or elegant, is at least consistent and keeps it separate from any issues with the existing installation.
 

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Unfortunately this is part of the process with old properties so don't worry about it too much. A lot of people have gone through the same procedure.
The only problem I see is the idiot connecting the breaker switch before the meter. How did he made this assumption?
Who in the world let him do jobs like this? It is basic knowledge that if you are paying for the electricity you're using - sure everything has to be wired after the meter.

As said above - keeping the two systems separate would make them more reliable. One won't trip the other and vice versa - so it's OK.
Once you get it all sorted - it all should be hassle free for good few years.
 

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Reason you can't use the existing consumer unit - RCD needs to be dedicated to the EVSE and also have no upstream RCD. For this reason, the days of installing EVSE on existing consumer units should be over.

The Smart+ also needs an external Type B RCD which is physically quite large. In my opinion it is all better in a separate 'garage pack' anyway

Sent from my SM-N976B using Tapatalk
 

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Reason you can't use the existing consumer unit - RCD needs to be dedicated to the EVSE and also have no upstream RCD. For this reason, the days of installing EVSE on existing consumer units should be over.
In my last house the charger was supplied through a 32A MCB in the section of the consumer unit without an RCD. It had two banks of five MCBs each with their own RCD and another section with space for two MCBs (smoke alarms and car charger) that didn't have an RCD.
 

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Hi everyone,
I'm here to try get some help and gain some electrical understanding as we seem to be having never ending issues trying to get a 7kW charger installed to our home.

For those who find the below far too long to read, my question basically comes down to:
I thought a 7kW charger would come off a 32A RCD protector within the usual consumer unit? Is this the case or do they run higher than this? If so, what do they require, a 100A protector?

Many thanks,
Rob
The DNO is king here! We have 2 x 32amp 7kw EV chargers at home. Both approved by WPD.

Our house has a 80amp main fuse , in a 100amp rated fuse holder. Our consumer unit is a biggy, 15 mcb slots, only 1 spare now with 2 EV chargers and solar installed. The CU has 1 main 100amp main switch.

The consumer unit is separated into 2 banks, a 7 and an 8 slot MCB, each bank is protected with an 80amp 30mA RCD. Each 32amp 7kw EV charger is then protected by a NSB32 32amp MCB. Obviously the two EV chargers are on each side of the CU bank so each is seperate and protected by that banks 80amp RCD.

We EV charge every night for the last 3 years and have less than a handful of RCD trips every year.
 

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Discussion Starter #8
Unfortunately this is part of the process with old properties so don't worry about it too much. A lot of people have gone through the same procedure.
The only problem I see is the idiot connecting the breaker switch before the meter. How did he made this assumption?
Who in the world let him do jobs like this? It is basic knowledge that if you are paying for the electricity you're using - sure everything has to be wired after the meter.

As said above - keeping the two systems separate would make them more reliable. One won't trip the other and vice versa - so it's OK.
Once you get it all sorted - it all should be hassle free for good few years.
So it was Electricity NW who installed the breaker switch before the meter, not the smart meter installer.
The guy from ENWL fitted it as sort of a favour on the side of the mains upgrade as I said we needed one. I didn't question it's position, I assumed he would have known.

Then the guy came to fit the smart meter a few days later. He never once queried this and now I get the impression that he should have as he is authorised to deal with anything after the mains fuse and so could have moved it.
 

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Well he was a total and utter dickhead
He has even fitted the two halves of the isolator plastic housing upside down.
There is a large half and a small half to the front housing and it can be fitted either way up - deliberately designed to do so depending whether the live comes in from the bottom or the top.
He should have fitted the large half of the housing on the bottom where the live entry comes in (well it should be from the meter not from the cutout!). This leaves just the small half of the housing on the exit side from the switch. This means you can switch off and remove the small part to fit the outgoing cables in without have dangerous access to the incoming live side as underneath the large half of plastic housing as the screw downs for the cables are not shrouded.

So it goes cutout ---> meter-----> isolator switch ----> then off to consumer unit or henly blocks to split into multiple consumer units.

At least he has wire clamp locked the right half - just that the plastic is on the wrong side
Jeez - where do they get these people from......
 
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