UK 100 Amps or 60 Amps

[freddo]

I’m surprised they didn’t fit a smart meter. I thought all suppliers were pushing for them.
I take it that’s because of rural setting and maybe bad mobile signal for the smart communications.

A couple of recent customers have told me they have been contacted by their suppler to book in fitting a smart meter only to be told they can't have one as they have off peak which isn't supported. The whole system is a joke.

 

[timhoward]

A couple of recent customers have told me they have been contacted by their suppler to book in fitting a smart meter only to be told they can't have one as they have off peak which isn't supported. The whole system is a joke.

We've also seen more than one example of this forum of smart meter installers not understanding off peak metering and having a go anyway, resulting in RCD's tripping every night...
It might not be such a bad thing if smart meter installers avoid these installations!

 

[AndyBuzz]

The better EV charges have a current transformer for the main supply and will adapt the charging to keep your total below 60A (assuming the house is below 60 of course!)

So if charging and you put on an electric shower it just throttles the car charge for 10 minutes or whatever you are using it for.

Bigger issue is if you plan lots of electric heating or a massive range-style cooker, though I think some of the fancy induction ones also have total demand throttling (or am I imagining that?)

Thanks pc1966
Interesting what you said on EV chargers with transformers.
Yes - the other thing I'd looked at is air source heat pump. My research suggests system design is a more constant background heating - less cyclic than your 20Kw typical gas boiler system. For larger older houses you'd need probably a min 4Kw system but run all the time in cold weather.
A lot of rural houses have no gas, so rely on oil / LPG. If this is phased out that leaves night storage / heat pumps.
Add EV to the equation and frankly I don't see how long term the grid will handle it all.

 

[AndyBuzz]

A couple of recent customers have told me they have been contacted by their suppler to book in fitting a smart meter only to be told they can't have one as they have off peak which isn't supported. The whole system is a joke.

Yes - the installer said that as it's economy 7.
Frankly I think I need to review the benefits now. Economy 7 used to be around half price. Now it's 22p day and 16p night, not a big difference any more.

 

[Julie.]

Thanks again for replies.
I've just looked up looped supply and now understand the concept.
Do SSE have accurate records of whether I am on a looped supply, and the supply cable size(s) ? 35 years ago !!
We are very rural, in one of a pair of cottages fed from overhead. The overhead runs about 400 yards to a more substantial set of overheads. I remember 35 years ago the linesman who installed our supply saying there is a 400 amp switch box there for isolating our overhead.
I think this might be expensive - or I just abandon it all and forget the EV charging 'future proofing'. Keep to petrol !!
I'll contact them tomorrow - maybe they will do a survey.
I'd have preferred my electrician to do this but he's ill at the mo.
Thanks all for your support and replies. Though I'm not an electrician I can understand all your replies and what the fundemental issues are.

When you apply for an EV charge point, you have to request permission from your supplier, it's a standard form which is available here https://www.energynetworks.org/assets/images/Resource library/Single-Electric-Vehicle-Charge-Point-and-Heat-Pump-Installation-Application-Form.doc

They then check their network diagrams, loadings etc before you can connect an EV charge point.

You can submit one yourself any time so consider putting one through and you will get your answer without any commitment on your part.

Note it's the same form if you want to install heat pumps as well.


Note, the fuse carrier states 100A as this is the maximum, just like a standard plug says 13A - you could have a 3A, 5A.... etc fuse installed.

One point is to look at the meter, it usually has a maximum of 80A, so that's a clear indication you wouldn't have a 100A fuse!

 

[AndyBuzz]

That’s the funny thing;
Our test certificates asks us to fill in a box what size the main fuse is…. But we are not allowed to pull it to find out

we have to go by the sticker on the fuse carrier… which in experience … is either “100A” or “60/80” which still doesn’t help… which is it? 60 or 80?
The carrier is moulded with 100A printed into the plastic, as others have said, that’s the rating of the carrier- the biggest fuse that can go in.

I’m surprised they didn’t fit a smart meter. I thought all suppliers were pushing for them.
I take it that’s because of rural setting and maybe bad mobile signal for the smart communications.

With all the regs changes covering even what sparks can have for lunch, I'm surprised that correct labelling of the main fuse isn't mandetory within regs. At work if we supplied any equipment everything HAD to be correctly labelled. Seems a bit odd to me that the DNO can have a blasé approach just because it's their fuse.
My main fuse was labelled 100amps, not moulded. The meter fitting guy scratched up the label so now you can't really read it at all.

 

[AndyBuzz]

When you apply for an EV charge point, you have to request permission from your supplier, it's a standard form which is available here https://www.energynetworks.org/assets/images/Resource library/Single-Electric-Vehicle-Charge-Point-and-Heat-Pump-Installation-Application-Form.doc

They then check their network diagrams, loadings etc before you can connect an EV charge point.

You can submit one yourself any time so consider putting one through and you will get your answer without any commitment on your part.

Note it's the same form if you want to install heat pumps as well.


Note, the fuse carrier states 100A as this is the maximum, just like a standard plug says 13A - you could have a 3A, 5A.... etc fuse installed.

One point is to look at the meter, it usually has a maximum of 80A, so that's a clear indication you wouldn't have a 100A fuse!

Thanks for the detail and esp the form link.
I have looked at my photo of the original meter - and yes it says 80 amps. Must admit I hadn't thought to look at it.

 

[Mikegh]

Can the op not use the off-peak for the car charging then?

I asked this ? I presume the economy 7 is the same as our day/night metering

Is there not enough spare capacity at night with the throttling u can do or is it because you specifically can't get permission on the 15kva supply here ?

 

[ferg]

In fairness to your Spark assuming that it was a 100 amp fuse installed is not the same as not knowing that it might not be.
Everyone makes incorrect assumptions at some point or another.
As previously stated some suppliers frown on pulling the main fuse.
Admittedly there were indications that it wouldn't be 100A but again it could have been a genuine mistake / brain fart / poor assumption rather than a lack of knowledge.

There is a thread on here somewhere about the daft things we have done as electricians that shows even talented knowledgeable tradesmen get it wrong sometimes.

 

[Colin Jenkins]

When you apply for an EV charge point, you have to request permission from your supplier, it's a standard form which is available here https://www.energynetworks.org/assets/images/Resource library/Single-Electric-Vehicle-Charge-Point-and-Heat-Pump-Installation-Application-Form.doc

They then check their network diagrams, loadings etc before you can connect an EV charge point.

You can submit one yourself any time so consider putting one through and you will get your answer without any commitment on your part.

Note it's the same form if you want to install heat pumps as well.


Note, the fuse carrier states 100A as this is the maximum, just like a standard plug says 13A - you could have a 3A, 5A.... etc fuse installed.

One point is to look at the meter, it usually has a maximum of 80A, so that's a clear indication you wouldn't have a 100A fuse!

Hello Andy.

Don't panic! The advantage of remaining at 60 amps if you can is that there is less fault energy present (therefore less damage) if something nasty goes wrong at the meter head or consumer unit. With LED lighting, improved insulation and improved technologies, domestic loads are reducing and you may be surprised to find your load current is significantly lower than the original circuit capacities. As posted above, many EV chargers can phase back when required to. I'd be surprised if a domestic cottage today got anywhere near to blowing a 60 amp fuse. Regards, Colin Jenkins.