Solar panels and battery - any real world reccomendations?

Bug One said:
Have you had the consumer unit tripping? I'm guessing that's your ovens, or some other high drain circuits all twisted in together. :o

The cable looks like 2.5mm - no different to the ones connected to the 20a mcbs. So that 32A for the three combined isn't giving any protection for a single cable being overloaded - the cable will melt before it trips.

I'd want all those on their own dedicated mcb in a bigger, more suitably sized consumer unit.
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Nope, which I suppose is more worrying and explains the melty cables. There is a fair amount going through that MCB, two floors of sockets and a garage. 6 rooms, one being the kitchen. There is a separate circuit for the oven (bloody wants to be), now whether the oven is actually plugged in to it is another matter. We haven't been in here that long, but I'll check later.
 
randal said:
There's space on the bar for another 3 modules by the looks of it, so splitting that spur, parts and the labour to fit and recable that would be a bit more palatable than £700 just before a solar install!
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Ideally, you should be doing the same for the other 32A next to it as well. The mcbs are there as a resettable weak point in the circuit in case the load ever exceeds the rating of the cable. Having a 2.5mm cable going into a 32a means that the cable is weaker than the mcb - so if you get a short, or too high load for the cable, it will start to overheat and eventually melt before the mcb trips.

The first 32a mcb is right - as that's got a higher capacity cable, so the 32a mcb is suitable. The other two are bodges and the mcb is no longer offering any protection to the circuits.

I think you're much better off getting this fixed properly. You're going to need at least 5 extra mcbs (including the extra one for the inverter).

I'd also be questioning the 15a mcbs for the 1.5mm cables. 1.5mm cable usually indicates a lighting circuit, and 15a is right on the limit of what I'd be comfortable putting through that sized cable. My 1.5s are either 6a or 10a mcbs.
 
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Bug One said:
Have you had the consumer unit tripping? I'm guessing that's your ovens, or some other high drain circuits all twisted in together. :o

The cable looks like 2.5mm - no different to the ones connected to the 20a mcbs. So that 32A for the three combined isn't giving any protection for a single cable being overloaded - the cable will melt before it trips.

I'd want all those on their own dedicated mcb in a bigger, more suitably sized consumer unit.

Most modern MCBs fit the same sized rail - give or take a bit of a wiggle.
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2.5mm if a ring main plus a 2.5mm spur with only one item on it is absolutely fine under BS7671 on a 32amp MCB and is the case in almost every UK house. That is most likely what we are looking at.

The oven if a high power one (many are not and just on a FCU on the kitchen ring) should be on 6mm which is probably the breaker to the left if not a power shower.

The regs state that you should not mix and match MCB brands, they need to be type-tested by the manufactuer.
 
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randal said:
Nope, which I suppose is more worrying and explains the melty cables. There is a fair amount going through that MCB, two floors of sockets and a garage. 6 rooms, one being the kitchen. There is a separate circuit for the oven (bloody wants to be), now whether the oven is actually plugged in to it is another matter. We haven't been in here that long, but I'll check later.
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Your electrican will test for acceptable continuity across that ring and advise given its size.
Personally I would have a seperate radial circuit put in for the garage.
Kitchen rings are usually the most heavily loaded and so often given a dedicated one.

There is conclusion jumping above that could lead to a ring main being placed on two seperate MCBs which would be very poor.
 
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randal said:
Makes sense, the spark said he didn't think the fault was anywhere else in the house. Does seem a bit daft to twist the cables when there's ample space in that MCB. I did ask him if it was OK to leave it like that and he made the "neaaaahhhhh should be" noise, but I might see if I can get him back to untwist, restrip and flatten.

That circuit is the basement and ground floor ring main, as for the spur I have no clue. I suspect it's the garage sockets, I'll see if I can trace the cable as the consumer is in the garage on the basement level. There's space on the bar for another 3 modules by the looks of it, so splitting that spur, parts and the labour to fit and recable that would be a bit more palatable than £700 just before a solar install!

I read somewhere that "new Hagar is compatible with old Hagar, that's the great bit about them" is that true?


Really appreciate the thorough run down, and explanation. Assuming you're a spark by trade? If so, job's yours if you're passing :D
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What is on the spur is important. Bug One might be along the right lines if that is in fact a radial (ie. with more than one socket outlet/FCU on it) that has been wired as a spur on the 32amp MCB and in that case the 2.5mm T&E is not correctly protected from overload and should be on its own 20amp MCB.
In the meantime yes get that ring tested for continuity ie confirming it is a ring, cleaned up and wired back in.
Given you are having solar your current consumer unit is NOT suitable as you have an RCD as a main switch. The inverter must be up stream of the RCD. Whether it needs its own RCD/RCBO will be determined by how it is wired (surface clipped cable does not, I would use hi-tuff for prudence personally) and whether it has DC leakage protection built-in to the inverter or not. My LuxPower does. If not you need a type B RCD+MCB or RCBO.
So the only alternative is a seperate new consumer unit for just the inverter, but that will be less cost effective long term.
As you see it gets quite complex quite quickly, and generally beyond solar installers knowledge / competence.
Actually not a spark, albeit do quite a lot of work still within the permissable and always to regs. Your CU is notifiable work so wrong side of that unfortunately! Started my training before ending up in a desk job. Probably should have followed the passion!
 
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Welshman said:
are any of these recent comments about solar and batteries?? all im seeing is comments on Mcb and electric boxes and quotes for electrical work
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Sort of fair, original context is his solar install. Still we're up to 346 pages so don't worry about it too much :cry:
 
BUDFORCE said:
Getting a smart meter installed Wednesday so we can setup an export tariff.

I hope we are not making a mistake giving some of the horror stories I've heard, time will tell.
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Had mine upgraded to the SMETS 2 a couple of days ago from the original not so very smart meters. All went well, I even got an upgraded double pole main switch on the tails between meter and CU. They didnt like mine because it only had 1 terminal screw per tail, seems now they have to have 2 clamping terminal screws per tail.
 
My dumb smart meters were finally replaced yesterday, checked the app last night and it seems the Gen1 electric meter carne back to life last week. Much rather have a Gen 2 though, and the IHD is more useful, as I can actually get the meter readings from it, more so the gas as that's outside.

How long does it take before the readings start showing up again?
 
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Ron-ski said:
My dumb smart meters were finally replaced yesterday, checked the app last night and it seems the Gen1 electric meter carne back to life last week. Much rather have a Gen 2 though, and the IHD is more useful, as I can actually get the meter readings from it, more so the gas as that's outside.

How long does it take before the readings start showing up again?
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My octopus ones usually appear in the afternoon for the previous day.
 
Ron-ski said:
My dumb smart meters were finally replaced yesterday, checked the app last night and it seems the Gen1 electric meter carne back to life last week. Much rather have a Gen 2 though, and the IHD is more useful, as I can actually get the meter readings from it, more so the gas as that's outside.

How long does it take before the readings start showing up again?
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My gas, leccy and export are normally on the website by lunchtime…..
 
Ron-ski said:
My meters were replaced yesterday as they'd stopped working last year, seems the electric meter started working last week, as that shows readings up to Wednesday, but no readings for yesterday or today. Hopefully they just need a while to finalise things.
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Ron, I think someone broke all the home displays on 28th Feb as they uploaded some new code which corrupted everything it seems. So I'm like you got new smart meters but they are acting dumb abouut giving out data to my phone apps or indoor display.
 
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