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Consumer Unit Rating

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GKSVE

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Ours is 100Amp but our sparks says he will not fit charger at 7.2kw unless it is uprated to 200Amps?
 
i assume you are on about mains consumer unit we had 7.2 kw fitted by electrician from suppliers Easee i mention fuse size it was not a problem and our main fuse is 65amp no one not even electric board have told us its not up to job plugged our mg ev es in a number of times taking advantage of cheap over night rates
 
100 Amp is the rating recommended for a 7.4kw charger in a domestic house. You can get by with 64amp but need to be careful what you else you have running in the house. 200 amps is overkill unless you have specific large load requirements (I can't think what that might be).
 
Are you on a single phase or three phase supply by any chance ?.
Which is not that common in a domestic setting I have to say.
200 Amps is massive and more likely to be seen in a commercial / industrial environment ?.
Normally, a standard domestic supply is normally protected by a main cut out fuse rated between around 60 - 100 Amps.
This can depend on the age of the home / age condition of electrical system at the property.
Some of the newer wall boxes, now have a load balancing facility that will use amp clamps attached to the main meter tails.
If the load at the property gets too high, while other electric appliances are in use at the same time, the EV wall box will throttle back on the charge offered to the car.
When the demand by other items reduces again, it will increase the power to the wall box.
If your property did require protecting by a 200 Amp fuse, I shudder to think what your electric bill would be with number of items running on a supply of that size :ROFLMAO:.
 
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GKSVE said:
Ours is 100Amp but our sparks says he will not fit charger at 7.2kw unless it is uprated to 200Amps?
Click to expand...
I don't think I have seen a 200A fuse.
Some people are on 60A fuses which need to be upgraded either to 80A or 100A.
How many electric ovens and showers are in the property?
 
Jomarkh said:
How many electric ovens and showers are in the property?
Click to expand...
With the vast array of electrical appliances on offer these days, it is not hard to reach the threshold of a 60 Amp rated fuse if you are a EV owner and using a wall box at the same time as in this example below.
These examples are a rough guide of course.
Example - Wall box 7.0 ( ish ) Kw’s / Single electric oven 3.5 ( ish ) Kw’s / Tumble Dryer ( 3.5 ) Kw’s.
Total load in Amps = 59.9 Amps.
An 11 KWh electric shower and the EV wall box on at the same time and you have hit 18 Kwh’s and you have WELL passed the recommended the safe work load of that fuse.
That is very close to 82 Amps !.



B5951B95-5436-42EC-8BDE-95D832705024.jpeg
 
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I can see the potential logic here...

The fuse board may have circuits totalling nearly 100amp already (although through diversity is unlikely to trigger) the spark wants a board rated to 200amp with 2 x 100amp banks so that they can safely add a 40amp circuit for the EV charger. In a commercial setting with 3 phases this would be quite normal. And a spark that usually deals with commercial stuff only may be forgetting that domestic supply is typically single phase and they should be querying how/why the property has circuits totaling close to 100amp.

Get a different spark.
they can install blocks and split your inbound between the CU and a separate 40amp breaker for the EVSE, and ensure a CT clamp is installed for the EVSE so that it can throttle back if more than 60amp draw is seen on the CU side.
 
Jomarkh said:
I don't think I have seen a 200A fuse.
Some people are on 60A fuses which need to be upgraded either to 80A or 100A.
How many electric ovens and showers are in the property?
Click to expand...
Really appreciate all feedback, thank you. This is getting very confusing! I forgot to mention that we and other cottages are supplied via the hotel in the grounds but with our own meters. However, I have been asked whether we have a looped supply but our meter is mounted on a backboard alongside the consumer unit, under the stairs, with the cables coming through 2 very neat holes making it impossible to see what exists behind this board/exceptionally neat installation! I haven’t a clue how to answer this question on the ENA form so how do I get an accurate answer? The financial costs seem horrendous if we are ‘looped’
 
You say you have cables coming through 2 very neat holes, well that to me means you might well be on a loop supply with next door, now that doesn’t mean you can’t use an EVSE, my house is on a looped with my next door neighbour and I have never had any issues at all, when it was installed DNO said it was fine and won’t be a problem and it hasn’t been, but yeah as Jomarth said above some pictures of your board meters and these 2 holes would be handy and help us help you further perhaps.
Les
 
N2STY said:
A lot of installers prefer to use and independent feed so it don't use your consumer unitView attachment 15894
Click to expand...
Agreed !.
My C.U. was a little "busy" lets just say, so the EV installer decided to go down the same route as yours, spilt the meter tails and then use two 'Henley Blocks" to run a new a dedicated supply to a stand alone single CU unit similar to yours ( circled in blue ).
100 Amp double pole isolation switch also ! (y).
 
GKSVE said:
Ours is 100Amp but our sparks says he will not fit charger at 7.2kw unless it is uprated to 200Amps?
Click to expand...
Are you using one of of these online installers? I have recently had a charger installed and did a lot of research before purchase. I first of all hesitantly entered my details into a few online "installers" with nice web sites. I had to submit photographs of my main fuse consumer unit, installation location etc. I soon regretted it. Multiple emails, text messages and phone calls followed. They wanted to replace my consumer unit despite there being spare capacity. The online sales person would often leave me on hold to speak to his manager (old double glazing sales tactics), and didn't seem to have much electrical experience. He offered to send round an electrician to carry out a "survey", ie give me a quote, for a price of only 70 pounds down from 120 which was a specially reduced rate for me. I eventually blocked all calls and emails.
I then got a few quotes, (free of charge), from reputable local electricians, chose one and now have a successfully working, neatly installed charger.
 
As an experienced time served electrician please tell your electrician he is a dick and to go back to school. Your meter is most probably rated to a 100A so by putting a 200A fuse in a most probably rated 100A cutout is a major fire hazard.
 
I use Checkatade to find someone suitable, if none of my mates have any recommendations.

My other half got 2 bathroom fitters details from some local Facebook group. They had apparently good recommendations. Further investigation shows the recommendations came from their associates - e.g. wives and family. Doesn't mean they are no good but makes you stop and think!!
 
GKSVE said:
Really appreciate all feedback, thank you. This is getting very confusing! I forgot to mention that we and other cottages are supplied via the hotel in the grounds but with our own meters. However, I have been asked whether we have a looped supply but our meter is mounted on a backboard alongside the consumer unit, under the stairs, with the cables coming through 2 very neat holes making it impossible to see what exists behind this board/exceptionally neat installation! I haven’t a clue how to answer this question on the ENA form so how do I get an accurate answer? The financial costs seem horrendous if we are ‘looped’
Click to expand...
I think if you have feed is from the other property the load will need to be taken in to account to that property not a easy one this.
 
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