What size is this supply?

[John-SJW]

A relative in West Cheshire sent me this pic. He is contemplating having an EV charger and other electrical appliances fitted. He asked me if he has a 60A or 100A supply. From this pic, it looks like a 100A supply with 60A fuse fitted for some reason. He wants it to be 100A. Any ideas?

 

[John-SJW]

It doesn't matter if the incoming cable is capable of 100A, it still doesn't mean that supply has a capacity of 100A.

DNOs apply diversity just as electricians do, the capacity of the distribution transformer determines how many supplies may be connected at 60A, upping some customers to 100A may well mean a larger transformer is required.

One cannot assume that because a certain size cable, fuse carrier, meter etc has been fitted that there is capacity.

I doubt the fuse has been changed, the meter fitter is likely to have removed the fuse, fitted meter, refited the fuse, applied new seals, and applied a label showing the fuse size.

Something tells me he was downgraded - just a hunch. If he was dowgarded to a 60A fuse, which does happen, you will find the DNO would have marked out streets or an area then put 60A in the lot. Or ensured 60A was inserted when a smart meter was fitted, as take up may be enough to make a difference in downgrading in an area. They do it by stealth. This maybe in preparartion for the EV charger onslaught, followed by elimination of gas. Hopefully in the interim they put in enough electrical capacity.

An all electric house they would have left alone, as the odd 100A draw off makes no difference here or there. Few houses with gas supplies are all electric. Especially those built with heating systems from new.

He needs to look in houses around to see if they still have 100A supplies. All those adjacent foolishly took up the big brother smart meter, so they all may have 60A fuses.

 

[DPG]

This is going to go on and on.

 

[Gavin John Hyde]

I had the DNO out once to pull a old fuse, tails were 16mm between cutout and meter, from meter to CU 25mm, it had a 100A fuse, due to tails being 16mm he said he would have to down rate to 80 or 60. I said no thanks wait there and got some 25mm off the van, then changed the tails and said we will keep the 100A if you dont mind, he phoned the depot and begrudgingly put it back in... i thought it was a matter of principle

 

[timhoward]

I’ve never known of a smart meter installer change a fuse rating, ever. I don’t think they are allowed to.
In fact they have a form for if the tails are undersized and tell the customer to contact a sparks. I’ve seen this a few times. In my area they kindly fit 25mm tails to an isolator too.

It seems rather pointless speculating about what might have been the case once, and which bunch of capitalists are to blame, the bottom line is it has a 60amp supply and if he really needs more then he needs to phone the DNO.

 

[John-SJW]

He is having PV panels on the roof to heat the DHW cylinder. Even this will make no impact.

 

[7029 dave]

I’ve never known of a smart meter installer change a fuse rating, ever. I don’t think they are allowed to.
In fact they have a form for if the tails are undersized and tell the customer to contact a sparks. I’ve seen this a few times. In my area they kindly fit 25mm tails to an isolator too.

It seems rather pointless speculating about what might have been the case once, and which bunch of capitalists are to blame, the bottom line is it has a 60amp supply and if he really needs more then he needs to phone the DNO.

I can only speak as a former energy provider MOP, we were not allowed to down grade or up grade cutout fuses, cant speak for other providers.

 

[John-SJW]

I had the DNO out once to pull a old fuse, tails were 16mm between cutout and meter, from meter to CU 25mm, it had a 100A fuse, due to tails being 16mm he said he would have to down rate to 80 or 60. I said no thanks wait there and got some 25mm off the van, then changed the tails and said we will keep the 100A if you dont mind, he phoned the depot and begrudgingly put it back in... i thought it was a matter of principle

I have the impression they told him to downgrade whenever he could. It would be fun if hubby had high current drawing equipment in his rear workshop the DNO man never knew about.

Why did he make a phone call to the depot? That makes no sese. Maybe he was told to drop the rating before going - a matter of policy.

 

[DPG]

Im getting the words conjecture and guess.

 

[John-SJW]

I can only speak as a former energy provider MOP, we were not allowed to down grade or up grade cutout fuses, cant speak for other providers.

How long ago were you with them?

 

[littlespark]

They do it by stealth.

You sure about that?
Sounds a bit of a conspiracy

 

[7029 dave]

How long ago were you with them?

I left at the end of 2020

 

[Julie.]

I remain in touch with colleagues who still work for the DNO, they would be apoplectic if a meter fitter started changing their equipment such as fuses!

 

[John-SJW]

You sure about that?
Sounds a bit of a conspiracy

Do you think the capitalists now running our utilities are whiter than snow?

 

[DPG]

Do you think the capitalists now running our utilities are whiter than snow?

They aren't sending blokes out in the middle of the night with increasingly small fuse sizes.

You don't use the word 'scamdemic' by any chance do you?

 

[timhoward]

Do you think the capitalists now running our utilities are whiter than snow?

Do you think anyone gives a flying fuse?

 

[Lister1987]

Bs1361 and bs88 service fuses are 30, 40, 50, 60, 70, 80, 90 and 100A

60, 80 and 100A being the common ones.


Others such as j type or A3, A4 etc are indeed 63A

That may be where I'm getting muddled.

 

[John-SJW]

Do you think anyone gives a flying fuse?

Yes they do. If you were old enough to remember before the money men came in, the service was vastly superior.

 

[DPG]

Going back to the original question, has your friend contacted the supplier yet?

 

[John-SJW]

Have not seen him yet. He was assessing going all electric with an EV charger. I asked him if his supply was man enough. So it is with him. If and when I will report back what the DNO says.

As a few have noticed, it looks like a full 100A supply with a 60A fuse, so it would be interesting what they say.

 

[nicebutdim]

As a few have noticed, it looks like a full 100A supply with a 60A fuse, so it would be interesting what they say.

No one has stated anything of the sort.

 

[littlespark]

Some EV chargers come with load shedding now… (or is that most chargers?)
They measure the total load of the house and will cut off the charger if someone turns the shower on or something… to decrease the total load at any one time.

So having a 60A main fuse shouldn’t be a problem.

 

[DPG]

Have not seen him yet. He was assessing going all electric with an EV charger. I asked him if his supply was man enough. So it is with him. If and when I will report back what the DNO says.

As a few have noticed, it looks like a full 100A supply with a 60A fuse, so it would be interesting what they say.

Can you give references for the posts from these few people.

 

[timhoward]

Some EV chargers come with load shedding now… (or is that most chargers?)
.....
So having a 60A main fuse shouldn’t be a problem.

Indeed.
A sign a thread is getting a bit long...when nothing seems to be being taken on board...and early answers get repeated again! (post #10)

As a few have noticed, it looks like a full 100A supply with a 60A fuse, so it would be interesting what they say.

Having just read all 52 previous posts, I gently suggest you are the only person who thinks it looks like that.
For once, a bunch of electricians actually all unanimously agree on something - that is an ex-parrot a 60A supply.

 

[littlespark]

Sorry, @timhoward , I didn’t look back that far.

 

[freddo]

A lot of that style of cutout around here are replaced by the DNO if greater than an 80A fuse is required.

 

[Risteard]

Bear in mind you have to apply to connect with advance permission from the DNO to have more than 60A per phase with an EV.

 

[John-SJW]

Indeed.
A sign a thread is getting a bit long...when nothing seems to be being taken on board...and early answers get repeated again! (post #10)

Having just read all 52 previous posts, I gently suggest you are the only person who thinks it looks like that.
For once, a bunch of electricians actually all unanimously agree on something - that is an ex-parrot a 60A supply.

No. Most thought it looked like a 100A carrier and tails and supply cables but clearly a 60A fuse..

 

[John-SJW]

Some EV chargers come with load shedding now… (or is that most chargers?)
They measure the total load of the house and will cut off the charger if someone turns the shower on or something… to decrease the total load at any one time.

So having a 60A main fuse shouldn’t be a problem.

That is the case with many. But if going all electric, with a 7kW plus induction hob and maybe an 11.5kW instant electric water heater or 9Kw immersion, electric UFH and a Quooker tap, etc. Something like a Garo may need to be used to de-prioritize the heating. Assuming the EV charger has integrated load shedding, if not then that will need de-prioritizing with the likes of a Garo,

That is if it is limited to 60A. If the supply can get to 100A then matters are easier, as been mentioned in the thread.

 

[DPG]

No. Most thought it looked like a 100A carrier and tails and supply cables but clearly a 60A fuse..

Yes, it is a 100A carrier. The DNO may not provide a 100A supply though. This is not hard to understand.

 

[John-SJW]

Yes, it is a 100A carrier. The DNO may not provide a 100A supply though. This is not hard to understand.

I am pretty sure most understood that from the outset.