80A PME Fuse

[chivers67]

Fellow DIY NOT people

We're thinking of going fully electric car wise sometime in the future, we currently have an 80A fuse on a PME supply.

Today we had our faulty Smart meter replaced by Octopus Energy, the chap even fitted a Dual pole Isolator! He mentioned to my wife we should contact the DNO to get this upgraded to 100A Fuse if we're looking to do that.

Three Bed Semi. Gas Combi boiler for two showers. Two Ring Finals - Sockets up & Down, One for kitchen, plus one radial for some down sockets. We do have a Garden Room fed from a separate Board via a Henley block and also another board for two brick sheds.

Thoughts on whether a 100A DNO fuse is required & Electric car too? After all most of any charging will take place at night with minimal power apart from freezers and a few bits & bobs with minimal consumption.

 

[ericmark]

I am sure, like me, you know what you are using when. So I know I use 7 kW overnight on a regular basis. So I know I would be using 60 amps on a regular basis, so would be a bit risky for me.

However, when my son got an EV from Octopus, he had no options as to the fitting of the charging module, the installers had strict instructions as what they could do, and unless you do not want to use the offer of 6p/kWh when all done by Octopus, then you don't have an option, you have to just stand back and let them do as they want.

 

[JohnW2]

We're thinking of going fully electric car wise sometime in the future, we currently have an 80A fuse on a PME supply. .... He mentioned to my wife we should contact the DNO to get this upgraded to 100A Fuse if we're looking to do that. .... Thoughts on whether a 100A DNO fuse is required & Electric car too?

There's obviously no electrical downside to upgrading to a 100A fuse/supply, so it really comes down to whether there are any significant financial issues. I imagine it varies between DNOs, but it seems with mine ("National Grid") that, provided their supply has adequate capacity and one's installation has 25mm² tails, they will usually upgrade to 100A for little or no charge. One can but ask!

 

[Murdochcat]

I can’t see the point. 80 A is more than enough as long as your sheds aren’t used for growing things all year

 

[plugwash]

If your cooking and heating are all gas then 80A is plenty. Even if you have an electric cooker and shower I suspect 80A will still be fine in most cases. If you start getting into electic for space heating then things could get tighter.

If you are worried about load, and the DNO won't upgrade the supply, many EV chargers nowadays have a grid limit feature, so they will reduce/stop charging if there is too much other load.