DIY solar battery storage

[user 34936]

Brilliant news. Welcome to the club

 

[Berserkerboy]

As said in this and other posts my G100 application has been accepted by Western Power. Hurrah!.
A 3kw AC coupled inverter with a 5kwh battery will be connected to a spare slot on the consumer unit.
I believe I am right in thinking that this is notifiable work?

As an aside: The electrician who installed our consumer unit gave me all the copy paperwork for the installation. All signed off, but I have never received any confirmation that it has been presented to the relevant authority. Should I be concerned?

 

[Geoff1946]

You may be able to see building control registrations on line, in the same place as planning permissions.
I can look up mine, Blackpool local authority. And my solar system was registered by the installer.

 

[Berserkerboy]

Cheers, I'll have a look

 

[Berserkerboy]

Notifiable?

 

[steptoe]

As said in this and other posts my G100 application has been accepted by Western Power. Hurrah!.
A 3kw AC coupled inverter with a 5kwh battery will be connected to a spare slot on the consumer unit.
I believe I am right in thinking that this is notifiable work?

As an aside: The electrician who installed our consumer unit gave me all the copy paperwork for the installation. All signed off, but I have never received any confirmation that it has been presented to the relevant authority. Should I be concerned?

A spare slot in your consumer unit,?
Make sure it doesn't share an RCD with any other circuits

 

[Berserkerboy]

I thought I'd be able to use one of the spare circuits that are currently blanked off. How should I go about connecting the AC coupled inverter if not?

 

[steptoe]

I thought I'd be able to use one of the spare circuits that are currently blanked off. How should I go about connecting the AC coupled inverter if not?
View attachment 13687

You are going to need a separate consumer unit.

 

[Berserkerboy]

That's not what I wanted to hear Steptoe!.
So this isn't going to be as easy as I thought it would be?
Are you saying I need to split the incoming tails for a totally separate consumer unit or install a sub-consumer unit?
I'm glad you brought this to my attention. Definately, notifiable work too.
Thank you.

 

[binky]

That's not what I wanted to hear Steptoe!.
So this isn't going to be as easy as I thought it would be?
Are you saying I need to split the incoming tails for a totally separate consumer unit or install a sub-consumer unit?
I'm glad you brought this to my attention. Definately, notifiable work too.
Thank you.

Never share an RCD with a solar system, the standards for inverters to shut down in the event of a grid failure, 3 seconds, means you could be kilked by the solar. In reality inverters shut down faster than that, but not necessarily as quick as an RCD, so if you say ran over a cable mowing the lawn, the RCD may trip, but the inverter carries on frying you.

Your board might be adaptible for a new circuit not shared with the solar, have a look inside if you feel able, and look for a third neatral bar.

 

[revor]

Your board might be adaptible for a new circuit not shared with the solar, have a look inside if you feel able, and look for a third neatral bar.

Looks like it would be possible to move the RH RCD to give a space between the RCD and main isolating switch for the inverter MCB. Would that be permissible?

 

[binky]

Looks like it would be possible to move the RH RCD to give a space between the RCD and main isolating switch for the inverter MCB. Would that be permissible?

as far as I'm concerned it is. Trouble is, if it hasn't got a third neutral bar, installing one is much easier said than done, and in that scenario I either install a mini CU or change the board.

 

[Berserkerboy]

Hey folks, thanks for all your input.
Unfortunately, I'm now away for 7-10 days and haven't had a chance to have a look at the CU.
I'll check as soon as I get back.
Will need to pick your brains again..

 

[revor]

The photo shows dual RCD's so chances are it will have 3 N bar. I have MK dual RCD CU and they have 3 N bars. 1 for each RCD and "incoming".

 

[steptoe]

The photo shows dual RCD's so chances are it will have 3 N bar. I have MK dual RCD CU and they have 3 N bars. 1 for each RCD and "incoming".

It doesn't have a Neutral bar for incoming,
The boards with 3 N bars were commonly known as High Integrity boards, so you could have some circuits on MCBs or RCBOs and not shared with the RCD circuits.

 

[Berserkerboy]

Morning all. Sorry for the late supply of this picture showing our CU.
I suspect you will tell me that it's no longer up to regs, as the solar shares an RCD?
Just the 2 neutral bars, but space to put another in?
What are my options folks? I need to put it right, and connect the inverter for the battery storage?
My thanks in advance.

 

[binky]

Morning all. Sorry for the late supply of this picture showing our CU.
I suspect you will tell me that it's no longer up to regs, as the solar shares an RCD?
Just the 2 neutral bars, but space to put another in?
What are my options folks? I need to put it right, and connect the inverter for the battery storage?
My thanks in advance.

there's space to rearrange the board, but you will need a spare plastic holder and a spare bit of busbar, and a neutral cable - I find it easier to just install a mini board than rearrange boards. Sometimes you can get a kit to convert to 'high integrity'.

 

[Berserkerboy]

Thanks Binky.
Just to confirm if you don't mind?
If I rearrange the board. Am I right in thinking that my electrician will be redirecting the neutral from the solar circuit to the grid side of the rcd? Would the new inverter for the battery storage need to be connected similarly?
The solar and battery circuits are then only protected by the mcbs?
If a mini-board is installed, I am effectively putting a fixed rcd on the circuits of these items? Can they both share that mini-board rcd or do they need dedicated ones?

Sorry for all the questions.
Just need to be sure of what I am asking the electrician to achieve. He's not MCS.
Thank you..

 

[michael8554]

The points made about PV not sharing a RCD caused me to checkout our PV, installed 10 years ago.

The Wylex plug-in-fuse CU is fed from an external 100A 30mA RCD.

The inverter AC output is fed to the CU via 2.5mm2 to a Wylex plug-in 30A MCB the installers added.

Shouldn't that be more like a 16A MCB, to protect the cable ?

There are suitable rotary breakers between the PV DC and the inverter, between the inverter and the FIT meter, and between the FIT meter and the 30A RCD in the CU.

Though there is one unplugged hole and no glands on some of the breaker cable entries.

If only I know then what I've learned from this forum.......

 

[binky]

Thanks Binky.
Just to confirm if you don't mind?
If I rearrange the board. Am I right in thinking that my electrician will be redirecting the neutral from the solar circuit to the grid side of the rcd? Would the new inverter for the battery storage need to be connected similarly?
The solar and battery circuits are then only protected by the mcbs?
If a mini-board is installed, I am effectively putting a fixed rcd on the circuits of these items? Can they both share that mini-board rcd or do they need dedicated ones?

Sorry for all the questions.
Just need to be sure of what I am asking the electrician to achieve. He's not MCS.
Thank you..

you want to be feeding energy to the 'grid side' of the RCDs and MCBs, so Live and neutral are 'upstrem of the RCDs. That way if the RCD trips coz you stuck a wet finger in a socket (please don't try doing that) it isolates you from the solar energy - the RCDs are twin pole and isolate Live and Neutral when tripped.

The solar and battery will need their own MCB - there's some debate about RCDing such ccts, under the new regs update we are suppossed to RCD (or use an RCBO to combine RCD and MCB protection into a single spare way) every circuit. Personally I think that is uneccessary as you can't plug any appliances into that cct , and it's acceptable to 'risk assess' a cct for RCD requirement. Solar inverters tend to have RCD protection for the AC side built in anyway. I also don't like RCD protection on fridges and freezers, so if doing a full rewire, I supply them with a dedicated cct - for some strange reason Freezers like to trip RCDs whilst you are on holiday!