I’ve just ordered an EV charger installation and was warned by British Gas (The installers) that my house had a looped mains which means a shared mains feed with my neighbour. This would need unlooping meaning each house would have its own feed in order to install the charger.
A week later, the mains provider has approved the installation with no mention of the looped mains issue. My question is, is this correct? And has anyone had an EV Charger installed where the mains is looped?
My mains is 100A and I can see two big cables in the floor, one to my meter and the other towards my neighbour. I believe the charger is 32A. The biggest load on the mains is the oven. Nothing else comes close.
Hoping there are some knowledgeable electricians here
I’m not an electrician, but from what I’ve read online this AI generated answer seems accurate.
Can you have an EV charger on a looped supply?
AI Overview
Yes, you can have an EV charger on a looped supply, but it requires prior approval from your local Distribution Network Operator (DNO)
A looped supply means your property shares a main electricity cable from the street with a neighbor, which can overload the grid if both homes draw heavy power simultaneously.
How the Process Works
DNO Application: Your EV installer must submit an ENA (Energy Networks Association) application to your DNO to check if your local network can support the new electrical load.
Conditional Approval: The DNO may approve the charger with load-limiting/load-balancing constraints (throttling the charger’s power when your home’s total electricity draw gets too high).
Unlooping (Delooping): In many cases, particularly for standard 7 kW chargers, the DNO will require the supply to be “un-looped” so both properties have their own independent supply.
Key Considerations
Cost: Separating a looped supply is completely free of charge in the UK, as it is funded by the DNO.
Timeline: The process can take anywhere from a few weeks to several months depending on your region and whether they need to dig up driveways or gardens.
Next Steps: Check who your local Distribution Network Operator is (e.g., UK Power Networks, National Grid) and contact your charger installer or energy provider to initiate the DNO assessment. You can find resources and guidance via Energy Networks Association.
A looped supply was a “ popular” installation method in the 1960s. It assumes a goid level of diversity and each house having a 60A fuse ( cut out). The cable is capable of more current than 60A each, but there are a number of assumptions in this ( ambienttemperature being one). If the DNO jas approved it, then good. However, you and your neighbour need to push for seperate supplies.
Thanks for that. Not something I’d found in my own Googling. It sounds like it is the mains feed from the street that is the limiting factor. The approval received is not conditional and I do know that our house is on a feed from the substation that only includes 4 semi’s(8 properties) which seems not excessive so all seems well.
Any excavation work would affect my neighbour as I have the main feed so I’m happy if they suffer no disruption.
Separate supplies would be the end goal as my neighbour wants a charger installing also so if the unloop needs doing then, it’s their property that would be affected and their perceived benefit.
If either of us wants a heat pump install, the same issue crops up so yes, separate supplies are definitely preferred.
My understanding is that ones that run central heating can draw 20-40A which is the same range as an EV charger. Also, the info on the suppliers website mentions heat pumps along with EV chargers and solar panels as increasing the requirements of residential mains supplies. I guess that all these things combined are serving to exceed the limits of older installations.
It is probably OK but a couple of things to note a looped supply is not normally a 100A fused supplyto an individual house normally a 60A fuse is fitted. The fuse casing/holder may say 100A (the cases are all the same), but the fuse inside may be smaller.
The other point is that it is not really about the individual draw of any device but the total amperage that may be operating concurrently from all devices.
For example
32A EV charger + 16A kettle and a 16A immersion heater running at the same time will challenge a 60A fuse. There will also be a background house consumption due to all the small devices running like fridges and freezers, plus all the stuff on standby, it can add up to another 1 to 2 Amps.
Most Smart chargers can have a current limit programmed in via their app or on device menu if you find any issues, and while you wait for the DNO to upgrade your supply.
We have a 7kW heat pump that runs the whole house. It never draws more than about 2,000W, so two thirds that of a kettle. It can’t heat hot water and the radiators at the same time so won’t use much more than that, unless you have your hot water set at 70°C or want to heat your house to 25°C.
We had the same issue when we installed ours a few months ago. The installers will be allowed to do it. I contacted National Grid about the de-looping process / job. The guy I spoke to suggested we’d eventually hear from them and that I could contact them again to chase up the job. I’ve heard nothing since and haven’t bothered to pursue it. Apparently their backlog of these types of jobs is absolutely massive. Goodness knows when it might eventually get to the top of the list.
The service is completely free. In our case the disruption would be to our neighbour’s drive, but she seemed okay with it when we mentioned it.
Our supply is looped, between 4 houses. Our 7kw Podpoint was recently installed without delooping - but we were warned that the next of the 4 to get a charger wouldn’t be so lucky.
This didn’t worry us too much, until we then decided to buy the house next door ! What goes around…
We are electric only here. The new house has storage heaters, plus the usual immersion, cooker etc. Plus there’ll be an EV charger and a battery to store the off peak electric. I’m planning on spending a hefty sum on getting three phase installed rather than messing around with delooping - unless the cost is totally prohibitive.
Potentially you could have voltage drop issues, if so I wouldn’t think this would be entirely due to the loop service, network loading, distance from the sub stn and network cable size will all impact on the voltage drop. If your supply voltage drops below statutory limits (230v - 6% = 216.2v) then the DNO is duty bound to resolve the issue. That is assuming you are not exceeded your supply capacity when the voltage is out of limits.
If you have the charger installed and you believe you are out of limits, easy to check if you are competent with a volt meter. Contact your DNO and they will install a voltage recorder to measure and record the voltage levels over a number of days, typically one week.
I find all this fascinating. Just shows how much we take for granted the electricity we use. I’m now hoping when installed the charger will operate at full power without issues. My neighbour has a PHEV and is looking at getting a charger. It will be interesting to see whether he gets unconditional approval.
I had another look at our main breaker and note that the seals were replaced at the same time new smart meters were installed 2 weeks ago. Exactly the same type and lettering as those on the new components, also they are all shiny and new. The breaker has a very clean and white 100A sticker on it on top of an old sticker. Is it likely that the engineer who changed the seals would have left a 100A sticker on if the fuse was a lower rating?
If not mentioned, contact and discuss with your home insurance provider, there can be issues. Minimum you need to inform them, some even wont cover the buildings.
Martin
