Ditching gas, going electric immersion only, a wee project

JKenH

I have to admire your determination. I hope you aren’t planning to move anytime soon as unless you find another eco enthusiast it can’t help with the valuation of the house. 

It reminds me of my son’s determination to electrify a Mazda MX5. He doesn’t like the way most conversions are done and is insistent on fitting a Tesla motor into the rear subframe (for better weight distribution) rather than front mounting and using the existing drive train as others do. I’m not fully aware of all the issues but the motor I think drives the wrong way so that has necessitated reversing the gearbox and he has also had to design a whole new rear subframe to accommodate the motor under the boot floor. Why do something the easy way when you can do it the hard way? You will probably have moved house before he finishes it. 

QrizB

Thanks for the update!

It sounds like one of those projects where thee's always something you can add or tweak. Much as JKenH says, I hope you're not planning to move house any time soon

Solarchaser

I commend your son, I actually plan to do very much the same thing to my car in the next few years, make sure he knows to reverse the oil pump too, or that tesla motor may run dry.

But I certainly dont plan on moving, not after all the money.... but really more the time and effort I've put into it.

michaels

What overnight tariff are you on, how many hours?

I ask because we fill the V2H car battery and charge the other two cars and heat a tank full of hot water and run the heat pump and the dishwasher and washing machine....and it gets pretty close to the 100A main fuse limit at times!

JKenH

michaels said:

What overnight tariff are you on, how many hours?

I ask because we fill the V2H car battery and charge the other two cars and heat a tank full of hot water and run the heat pump and the dishwasher and washing machine....and it gets pretty close to the 100A main fuse limit at times!

There is quite a margin on the main fuse. I accidentally put 124A through mine for a few minutes a couple of years ago.

NedS

JKenH said:

michaels said:

What overnight tariff are you on, how many hours?

I ask because we fill the V2H car battery and charge the other two cars and heat a tank full of hot water and run the heat pump and the dishwasher and washing machine....and it gets pretty close to the 100A main fuse limit at times!

There is quite a margin on the main fuse. I accidentally put 124A through mine for a few minutes a couple of years ago.

Yes, they are slow blow type fuses, so shouldn't be an issue if you are over for a short period of time (assuming your wiring can also handle the higher load). Note though that a lot of properties are on an 80A supply, and some are still on 60A.

Solarchaser

michaels said:

What overnight tariff are you on, how many hours?

I ask because we fill the V2H car battery and charge the other two cars and heat a tank full of hot water and run the heat pump and the dishwasher and washing machine....and it gets pretty close to the 100A main fuse limit at times!

Intelligent octopus, so 6 hours at 7p.
Batteries about 7.5 Kw, tanks also about 7.5Kw which takes it to 15 ish, then the car is about 7.5kw also so around 23 once you add in background load, however I have a zappi charger, and an eddi heater and both are set to 90a maximum for the house, so if we decide to run a dryer overnight or the dishwasher etc, rather than it spiking over, the eddi will reduce to around 1Kw from 3ish, and the zappi will run all the way down to 4kw if needed, so no danger to my fuse.

Side note, I have 12Kw of heating elements, but in the smaller tank I put the two elements in series, as the tank was heating too fast and uneven, and so when you put 2 x 3Kw heaters in series, you get a 1.5Kw draw, hence the tanks being 7.5Kw

Martyn1981

NedS said:

JKenH said:

michaels said:

What overnight tariff are you on, how many hours?

I ask because we fill the V2H car battery and charge the other two cars and heat a tank full of hot water and run the heat pump and the dishwasher and washing machine....and it gets pretty close to the 100A main fuse limit at times!

There is quite a margin on the main fuse. I accidentally put 124A through mine for a few minutes a couple of years ago.

Yes, they are slow blow type fuses, so shouldn't be an issue if you are over for a short period of time (assuming your wiring can also handle the higher load). Note though that a lot of properties are on an 80A supply, and some are still on 60A.

Yep, slow blow as you say. We had our main fuse upgraded as part of the car charger install. We were WPD then (now National Grid DNO). They replaced the 60A fuse and box with a 100A box, but an 80A fuse, saying they couldn't justify a 100A fuse.

Since then, with Nat Grid taking over, they are now not installing 100A fuses, and may even (if I recall correctly) replace a 100A with an 80A when found during work. The report was about a year ago I think.

But what struck me, was that they said an 80A fuse would operate 'fine' at 100A for several hours. I think they also said the main purpose of the fuse is to protect properties from a fault from the DNO side.

I may be able to find the document if you're interested.



Edit - OK, couldn't leave it there, seemed too important, and it was easier to find than I'd thought. Whilst I saw it about a year ago, it's actually dated 2023:

NGED Standardisation of Fusing to 80A

Although NGED is not going to offer connections incorporating a fuse of 100A within domestic style cutouts, a customer should see no difference with the short term capacity made available with a supply provided through an 80A fuse. This is because an 80A fuse is capable of permitting the flow of up to 100A for up to four hours.

When work is taking place on domestic style cutouts (replacement or maintenance), where 100A fuses are found after the implementation date of this document, these fuses will be replaced with 80A fuses.

NedS

Martyn1981 said:

NedS said:

JKenH said:

michaels said:

What overnight tariff are you on, how many hours?

I ask because we fill the V2H car battery and charge the other two cars and heat a tank full of hot water and run the heat pump and the dishwasher and washing machine....and it gets pretty close to the 100A main fuse limit at times!

There is quite a margin on the main fuse. I accidentally put 124A through mine for a few minutes a couple of years ago.

Yes, they are slow blow type fuses, so shouldn't be an issue if you are over for a short period of time (assuming your wiring can also handle the higher load). Note though that a lot of properties are on an 80A supply, and some are still on 60A.

Yep, slow blow as you say. We had our main fuse upgraded as part of the car charger install. We were WPD then (now National Grid DNO). They replaced the 60A fuse and box with a 100A box, but an 80A fuse, saying they couldn't justify a 100A fuse.

Since then, with Nat Grid taking over, they are now not installing 100A fuses, and may even (if I recall correctly) replace a 100A with an 80A when found during work. The report was about a year ago I think.

But what struck me, was that they said an 80A fuse would operate 'fine' at 100A for several hours. I think they also said the main purpose of the fuse is to protect properties from a fault from the DNO side.

I may be able to find the document if you're interested.



Edit - OK, couldn't leave it there, seemed too important, and it was easier to find than I'd thought. Whilst I saw it about a year ago, it's actually dated 2023:

NGED Standardisation of Fusing to 80A

Although NGED is not going to offer connections incorporating a fuse of 100A within domestic style cutouts, a customer should see no difference with the short term capacity made available with a supply provided through an 80A fuse. This is because an 80A fuse is capable of permitting the flow of up to 100A for up to four hours.

When work is taking place on domestic style cutouts (replacement or maintenance), where 100A fuses are found after the implementation date of this document, these fuses will be replaced with 80A fuses.

Yes, that's correct.

I found and read (and shared somewhere here) that document in 2024 when NG replaced my 60A fuse with 80A following our ASHP installation. NG were quite interested to see what type of cutout box I had (housing the fuse) as I believe some are now deemed unsafe and need replacing (wrong type of plastic). NG had me send them photo's before they booked the engineer visit so they knew whether they were just replacing the fuse with an 80A or if they needed to replace the whole cutout. Luckily for me it was just the fuse, and they were all done in less than 5 mins.

Qyburn

We have a 100A fuse in the cutout, but we're served by a 16kVA transformer (data plate also says 64A so I'm not sure if the supply is 64A or 66).