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pedg

100A fuse upgrade: meter to consumer unit?

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pedg

Hopefully this is the right place to ask this question. Apologies if not.

 

We need to get our 60A main fuse upgraded to a 100A fuse to handle the addition of battery storage and EV charge point.

 

Due to various rules it appears we need someone from the power supply company, someone from the people we are buying electricity from and our own electrician there at the same time as each is only allowed to change things in their own areas?

 

What power company and provider need to do is, I think, clear, if perversely over-regulated (provider adds bigger wires to the meter so that power company person can connect them to new fuse). My confusion is about what I need our electrician (once we can get hold of one) to do? Power company says they would need to upgrade cable between the meter and the consumer unit but our current set up is more complicated than that.

 

(apologies if not using the right terms).

 

Currently meter goes to a junction box where the solar PV comes in. Then another ongoing cable goes, via an 80A RCCB, to a second junction box. Off this are the main consumer unit,  subunit for the outhouse and currently redundant connection which we hope to use for the battery and EV connections.

 

My guess is that we need to upgrade the cable from meter to first junction box, the cable from that junction box to second junction box and the RCCB with something that can handle a higher amperage. Beyond the second junction box none of the things connected should be drawing anything near 100A individually so would hope/assume not of the other wires need upgrading?

 

So question is what do we need to get an electrician to do to appease the power supply company (UK power networks as in Cambridge)?

 

Thanks for any help.

 

 

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pedg
9 hours ago, binky said:

batteries have vastly improved with the move to Lithium. Payback tends to be long as most people will only discharge the battery once a day, which usually returns about 12 years as a payback when I do some rough numbers. However, with an electric car to flatten the battery. the number of cycles per day could easily be 2 ( but not in winter) , so payback would then be 6 years, but then if you can charge the car battery, does it make sense to have the AC battery?  To me, batteries really suite people who just hate the energy companies and are prepared to pay as little as possible to them, but the numbers are getting better all the time.

The reasons we are going for a battery now are:

Better use of the solar

When no solar can take advantage of variable tariff to save money

The variable tariff allows cheaper charging of an EV

Less worry about using electrical appliances in the peak period.

I am a nerd and enjoy spending time trying to optimise the whole thing

 

(not necessarily in order)

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binky
13 hours ago, pedg said:

The reasons we are going for a battery now are:

Better use of the solar

When no solar can take advantage of variable tariff to save money

The variable tariff allows cheaper charging of an EV

Less worry about using electrical appliances in the peak period.

I am a nerd and enjoy spending time trying to optimise the whole thing

 

(not necessarily in order)

 

Nothing wrong with being a nerd, one of my best customers taught me an awful lot about PV. He installed air con (this was before batteries) to use leccy in summer / provide some heating in cooler times of year. Built his own website linked to local Univesity weather station etc etc. The sort of stuff I always think about doing, but never actually do! 

 

Out of interest, what do you think the financial gain for you is? 

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pedg
3 hours ago, binky said:

 

Nothing wrong with being a nerd, one of my best customers taught me an awful lot about PV. He installed air con (this was before batteries) to use leccy in summer / provide some heating in cooler times of year. Built his own website linked to local Univesity weather station etc etc. The sort of stuff I always think about doing, but never actually do! 

 

Out of interest, what do you think the financial gain for you is? 

 

Difficult to be accurate as I am thinking of it more as a 3 part mutually beneficial thing with agile tariff, battery and EV.

 

On the EV side depends on how often it needs charging. Currently don't drive that much but when it becomes only a couple of quid to do say a return trip to the coast then expect may drive more. If we said as an example that we got a car with a 64KwH battery and had to do the equivalent of a full charge 2 times a month. If each kW going in a 10p cheaper (often get 2 or 4 p in agile) then that's 64 x 24 x 10p that's £62 a year. But the financial part is only part of the thing as there is also the reduction in climate guilt when you do go out in it and as I said makes driving for pleasure more attractive.

 

I expect the battery system to pay for itself in about 8 or 10 years plus obviously at the end of that time the system will still have some worth. But as with the EV as well as the financial part the battery removed (or at least reduces) the having to worry about when to do things like have the oven on or put the washing on. Can't be the only people with PV who currently go. 'Suns out, lets put some washing on' which can lead to 'lets not put the washing on yet there might be some sun later'. Having the battery means we could generally do these things whenever we wanted.

 

The aircon thing is sort of interesting as I see there is a move to try and eventually ban the sale of new gas boilers with people being moved more towards heatpumps as domestic gas heating contributes a large fraction of the CO2 produced in the UK. If that happens then I can see variable tariffs and batteries being more attractive as even with the energy advantage of heat pumps going to be quite a few kW to heat a house.

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pedg

As a final point on this spark came round and has recommended upgrading to 100A and rewiring the whole lot to a single consumer unit using RCBOs and a surge protector.

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Murdoch
1 hour ago, pedg said:

As a final point on this spark came round and has recommended upgrading to 100A and rewiring the whole lot to a single consumer unit using RCBOs and a surge protector.


that sounds like a step forward

 

 have you been able to establish whether you can have a 100a fosse?

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pedg
50 minutes ago, Murdoch said:


that sounds like a step forward

 

 have you been able to establish whether you can have a 100a fosse?

 

Having a visit from the DNO on the 11th and they say they will do the fuse upgrade at the time if they can. Spark coming to do the work next Friday so hopefully should be all nice 23mm wiring in place before then with cable direct to the consumer unit. Can't get the supplier in to do anything with the meter as on the cusp of changing suppliers at that point but spark does not think that will be a problem (as in legally, as far as I can tell, only the supplier should change the cables on the meter but that is not how it appears to work in practice).

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Murdoch
48 minutes ago, pedg said:

 

Having a visit from the DNO on the 11th and they say they will do the fuse upgrade at the time if they can. Spark coming to do the work next Friday so hopefully should be all nice 25mm wiring in place before then with cable direct to the consumer unit. Can't get the supplier in to do anything with the meter as on the cusp of changing suppliers at that point but spark does not think that will be a problem (as in legally, as far as I can tell, only the supplier should change the cables on the meter but that is not how it appears to work in practice).

 

Thanks for the feedback - sounds like a good outcome for now and the future.

Edited by Murdoch

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pedg
1 hour ago, Murdoch said:

 

Thanks for the feedback - sounds like a good outcome for now and the future.

 

Assuming the work goes well. Assuming the fuse gets upgraded. Assuming the spark can be persuaded to do the final installation of the AC Inverter (they are going to have a look). Assuming no problem moving suppliers (as alleged smart meter has self-lobotomised itself) then hopefully fine!!

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Phoenix
On 25/07/2020 at 09:24, binky said:

 

Nothing wrong with being a nerd, one of my best customers taught me an awful lot about PV. He installed air con (this was before batteries) to use leccy in summer / provide some heating in cooler times of year. Built his own website linked to local Univesity weather station etc etc. The sort of stuff I always think about doing, but never actually do! 

 

 

I always think one of the productive uses is if your EV is parked up in the day (possibly less rare than it used to be with WFH and all that, then as the chargers in the cars are generally constantly varible, then theres scope for a ev supply point that takes input from a few CTs (main tails, its own output or supply circuit and the PV circuit) and works out the best charge rate (this is communicated to the EV via the PWM rate on one of the pilot pins btw) to dump all the spare solar energy into the EV battery, rather along the lines of those immersion heater controllers you used to get. Not sure if theres such an item yet

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ProDave
23 minutes ago, Phoenix said:

 

I always think one of the productive uses is if your EV is parked up in the day (possibly less rare than it used to be with WFH and all that, then as the chargers in the cars are generally constantly varible, then theres scope for a ev supply point that takes input from a few CTs (main tails, its own output or supply circuit and the PV circuit) and works out the best charge rate (this is communicated to the EV via the PWM rate on one of the pilot pins btw) to dump all the spare solar energy into the EV battery, rather along the lines of those immersion heater controllers you used to get. Not sure if theres such an item yet

I know someone that did that successfully with a Toyota Prius PHEV, though the response time to variations in charge demand rate were not very fast.

 

He has never been able to get that to work now he has a Tesla, it seems to ignore the "standard" input signals.

 

This sort of thing is firmly in "boffin's" territory at the moment, when it should be a mainstream standard product.

Edited by ProDave

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Phoenix
1 hour ago, ProDave said:

I know someone that did that successfully with a Toyota Prius PHEV, though the response time to variations in charge demand rate were not very fast.

 

He has never been able to get that to work now he has a Tesla, it seems to ignore the "standard" input signals.

 

 

 

At between 3% and 7% on the duty cycle it seems to drop into a mode where it sounds like it sends data over the pilot pins to set it all up, so I guess thats what goes on with the Teslas, they do seem to be like the Apple of the EV world. I imagine it would probably be possible to decode whats going on, but the level of boffin-ry required goes up.

 

I don't understand the need for it, the standard communications set up gives plenty of control over what you need, and is well documented and simple enough that it doesn't require complicated hardware to interface with.

 

 

 

 

ev charge rate.jpg

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binky

the idea of using your car as your PV battery and even backfeeding the house has been knocking around for a while, although I never saw much point of discharging from the car to power the house.

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Phoenix
2 hours ago, binky said:

the idea of using your car as your PV battery and even backfeeding the house has been knocking around for a while, although I never saw much point of discharging from the car to power the house.

 

Agreed, best just use it for driving otherwise its pointless wear on the battery.

 

Any products you know of which do more or less what I describe?

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binky
23 hours ago, Phoenix said:

 

Agreed, best just use it for driving otherwise its pointless wear on the battery.

 

Any products you know of which do more or less what I describe?

nothing springs immediately to mind, but I don't install much battery equipment. Everything I have fitted seems to have lots of programming options which I have mostly ignored as surplus to requirement. I've always worked on PV charges battery, and battery release energy as and when needed. 

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