Upgrade of house main fuse

[Susanna]

I am on a looped electricity supply. I (and my neighbour) originally had 60amp cutouts. I was told there was no issue running my Wallbox, but subsequently, my neighbour declined having their driveway dug up to have a new service connected. I don’t blame them, btw.
I used my 4 hour cheap window to run my dishwasher and washing machine also, for well over a year with no problems.

Ultimately, I was contacted by National Grid, when it came to their attention that nothing had been done. After their site visit, and in consultation with the neighbour, both cutouts were upgraded to 80amps, with no need to ‘deloop’ us. They stated that 80amp cutouts were the maximum that would be fitted to domestic properties.

Edited to say that my electrician correctly contacted the DNO, Western Power, before installation of the Wallbox, as it was they who identified the direction of the looped supply, and notified my neighbour of the need to have a new service to their property. We are all detached, and not adjacent - quite weird that we were looped at all.

 

[Brian0]

I did read on the site that Octopus sparkies are qualified to upgrade the fuse when installing charger?

Not what their engineer told me last week. Or at least they cannot change the cutout. Perhaps 60A to 80A is acceptable provided the tails are 25mm as the fuses are the same size, but we needed 100A, which has a larger holder, so have to wait for SSEN. As I understand it (and my experience so far ) SSEN have been fairly quick to respond.

Just to follow up on the DNOs have a database thing. I checked with SSEN and their records show our house as 100A fused. The fuse holder is labelled as 100A (actually part of the moulding), but EdF, who put in the smart meters have put in a 60A fuse and put EdF stickers all over it, which don't give the rating of the fuse.

 

[mg4mc]

Like @Hairyfool said. The DNO needs to approve that the street supply can provide the extra load and next time the meter reader calls they will report back that the main fuse has been tampered with as the seal will be broken.
Why not give them a call and ask how long you would need to wait for them to upgrade the fuse?

My fuse seal was broken for 10+ years and nothing happened? It only got resealed recently by the Octopus engineer who fitted my Ohme.

 

[gazza487]

My fuse seal was broken for 10+ years and nothing happened? It only got resealed recently by the Octopus engineer who fitted my Ohme.

My charger was installed and the fuse seal was magically gone!

Smart meter installer, resealed it and also put seals on the Henley blocks. Still waiting since Oct 23 for an unlooping but I have my charge sooooo.

 

[Brian0]

Whilst on the subject of regulation/notification, as part of the installation you should also be given an Electrical Installation Certificate and (probably) Building Regulations Certificate of Compliance.

When your house burns down the insurance company will want to see these.

 

[Bluemotor]

Whilst on the subject of regulation/notification, as part of the installation you should also be given an Electrical Installation Certificate and (probably) Building Regulations Certificate of Compliance.

When your house burns down the insurance company will want to see these.

Unless they are burnt at the same time!?

 

[bobbarley]

Before we had the fuse / cutout upgraded (the 60A holder is too small to take a 100A fuse) I used to regularly run 7KW charger + Washing machine + dishwasher + immersion heater in the 4hr Octopus Go window. It never blew the fuse, so you will probably be OK without the upgrade. However the rules have changed since my charger was put in so they will likely need to do a fuse upgrade anyway.

That’s useful to know thanks! Out of interest, what prompted you to get it upgraded retrospectively?

 

[Bluemotor]

That’s useful to know thanks! Out of interest, what prompted you to get it upgraded retrospectively?

We changed from a gas cooker to electric when we had the kitchen done, this then required a new CU as well. Whilst I was researching the changes I realised that I only had a 60A house fuse & might be pushing my luck with the extra load. As it was a free upgrade, I thought I might as well future proof the supply so had the fuse and cutout changed. It did take some months though.

 

[Riggers]

I thought I would share my recent experiences with getting a house supply fuse upgrade, as it might help others faced with the same problem.

Although I already have a 7 KW car charger installed, it was put in some years ago when EVs and chargers were still very new. Nowadays however, the installers are more concerned about whether the total house demand can be met through the house main fuse. So when we recently had our kitchen re- fitted and replaced the gas cooker with an electric one, questions were raised about if our 60A house supply fuse would be sufficient to cover cooker (30A), charger (30A), immersion heater (16A) dish washer (10A), washing machine (10A) and anything else that might be on at the same time.

So I checked my local DNO website (SSEN; this is not the same as you pay the bill to like British Gas, Octopus etc). After some searching it seems I needed to request a Load Check through the website. This was a free and an agent came out after a couple of weeks to review my supply. He took lots of photos of the supply set up and told me he couldn’t just fit a bigger fuse because the holder (‘Cut Out’) wouldn’t take it. Some weeks later I was then send a quote from SSEN for the replacement of the fuse and cut out. Total cost £0.00. I returned the signed quote and another few weeks later some new agents turned up to do the work. This involved removing the old fuse, smashing up the old black cut out with a hammer and large screwdriver (I kid you not!) until just the 2 bare live mains supply cables remained. The new cut out was then attached to the cables and a new 100A fuse fitted, along with replacement wooden back board (see photos). Overall it took them about 30mins.

So after some months, I have a 100A supply and much less risk of blowing the mains supply – all at no cost, but quite a few emails! I wondered if anyone else has faced this problem?
View attachment 19669View attachment 19670

Very interesting, thanks for sharing, I might need to do the same and it's good to know the procedure.

 

[Bigralphie]

When my smart meters were fitted by BG they put an 80A sticker on my 100A fuse holder

 

[johnb80]

Whilst on the subject of regulation/notification, as part of the installation you should also be given an Electrical Installation Certificate and (probably) Building Regulations Certificate of Compliance.

When your house burns down the insurance company will want to see these.

If your house has burned down they wont be there any more

 

[RobFarrant]

I thought I would share my recent experiences with getting a house supply fuse upgrade, as it might help others faced with the same problem.

Although I already have a 7 KW car charger installed, it was put in some years ago when EVs and chargers were still very new. Nowadays however, the installers are more concerned about whether the total house demand can be met through the house main fuse. So when we recently had our kitchen re- fitted and replaced the gas cooker with an electric one, questions were raised about if our 60A house supply fuse would be sufficient to cover cooker (30A), charger (30A), immersion heater (16A) dish washer (10A), washing machine (10A) and anything else that might be on at the same time.

So I checked my local DNO website (SSEN; this is not the same as you pay the bill to like British Gas, Octopus etc). After some searching it seems I needed to request a Load Check through the website. This was a free and an agent came out after a couple of weeks to review my supply. He took lots of photos of the supply set up and told me he couldn’t just fit a bigger fuse because the holder (‘Cut Out’) wouldn’t take it. Some weeks later I was then send a quote from SSEN for the replacement of the fuse and cut out. Total cost £0.00. I returned the signed quote and another few weeks later some new agents turned up to do the work. This involved removing the old fuse, smashing up the old black cut out with a hammer and large screwdriver (I kid you not!) until just the 2 bare live mains supply cables remained. The new cut out was then attached to the cables and a new 100A fuse fitted, along with replacement wooden back board (see photos). Overall it took them about 30mins.

So after some months, I have a 100A supply and much less risk of blowing the mains supply – all at no cost, but quite a few emails! I wondered if anyone else has faced this problem?
View attachment 19669View attachment 19670

Most new EV chargers can sense the load in the house and adjust itself to only draw what is available, or the charger cuts out if it is going to over load the house, it depends on how it is set up (in the settings), I have 100A supply and sometimes still hit the limit, first of all I set the EV charger to a 26A limit, then I found the setting to allow the charger to adjust itself, so I put it back to 30A, for a ProjectEV charger these settings were in the engineers area of settings which needed a code, I acquired the code from a ProjectEV engineer, he said they usually are set to a default code of 000000, that’s 6 0’s.
FYI I have Octopus energy night tariff 12:30 to 4:30 @ 9p per Kw, I had set both the EV charger and the car settings to charge at that time for it to work.

 

[tsedge]

When my smart meters were fitted by BG they put an 80A sticker on my 100A fuse holder

That's a good point, just because it says 100A on the outside does not mean that's the rated fuse on the inside.

Whilst on the subject of regulation/notification, as part of the installation you should also be given an Electrical Installation Certificate and (probably) Building Regulations Certificate of Compliance.

When your house burns down the insurance company will want to see these.

That all depends on the apparent cause of the fire. EIC yes, if it was an electrical fault traced to the charger install, if the records were not burnt in the fire, BRCC? I highly doubt that would come up.

 

[Deleted member 7316]

That's a good point, just because it says 100A on the outside does not mean that's the rated fuse on the inside.

My DNO had to come out because there was no rating on the fuse carrier or one visible on the fuse itself. Their engineer couldn’t find a rating either but had decided to replace the whole terminal and set up an earth from the supply so I could come off the earth rod.

 

[DBedford]

In what way is it dangerous? Thats what the fuse is there for.

Sorry for the late reply John. dangerous only in the way that no one wants to wait days for the network provider to attend and replace a fuse. Better to gat a 100 A cartridge fitted from the outset.

 

[Nicko]

If you are adding load get your cutout upgraded. I am an electrical engineer and I fitted a podpoint with the CT to limit the current as my cutout was fused at 60A. I charged my car approx. 8pm and I went in the garage where the mcb board is and could smell burning. I went to the cutout and the smell was coming from it. I turned off the consumer unit and the charger circuit and pulled the main fuse. The fuse was well burnt. The actual tail connection was loose and the cable melted. Western power came out and stated when they put my smart meter in they did not do the connection tight enough. This would have gone unnoticed if I had not put the extra load onto the supply. Get the cutout changed to make sure the connections are correct. At least I now have a 80A cutout.

 

[johnb80]

If you are adding load get your cutout upgraded. I am an electrical engineer and I fitted a podpoint with the CT to limit the current as my cutout was fused at 60A. I charged my car approx. 8pm and I went in the garage where the mcb board is and could smell burning. I went to the cutout and the smell was coming from it. I turned off the consumer unit and the charger circuit and pulled the main fuse. The fuse was well burnt. The actual tail connection was loose and the cable melted. Western power came out and stated when they put my smart meter in they did not do the connection tight enough. This would have gone unnoticed if I had not put the extra load onto the supply. Get the cutout changed to make sure the connections are correct. At least I now have a 80A cutout.

In fairness, if you'd had you fuse uprated to `100 amp it wouldnt have made any difference, a loose connection will still burn. A bit naughty pulling the main fuse yourself !

Sorry for the late reply John. dangerous only in the way that no one wants to wait days for the network provider to attend and replace a fuse. Better to gat a 100a cartridge fitted from the outset.

Nobody waits days if a main fuse is blown, theyre there pretty much straight away. An upgrade is a good idea for sure but not dangerous at all to continue to charge your EV whilst waiting.

 

[Nicko]

In fairness, if you'd had you fuse uprated to `100 amp it wouldnt have made any difference, a loose connection will still burn. A bit naughty pulling the main fuse yourself !


Nobody waits days if a main fuse is blown, theyre there pretty much straight away. An upgrade is a good idea for sure but not dangerous at all to continue to charge your EV whilst waiting.

I am qualified to pull the fuse and it was done under no load so totally safe!
The point I was making was not for the upgrade but to have your connections checked. They might be fine but when you put more load onto your system if the connection is not tight then what happened to me will happen.

 

[mg4mc]

When I had my charger installed and the electrician had to split the tails from the main fuse, he found the feed connections to the existing consumer unit were loose! We had that replaced about four years ago when the kitchen was redone. Scary thing is the electrician who did that was the guy who had the contract for the school where my wife worked at the time.

 

[bobbarley]

So my electrician has said 60A is more than enough so he doesn’t need to contact the DNO. Looking at the form it’s impossible to fill in without being qualified electrician. Leaves me in a bit of a position