Solar panels and battery - any real world reccomendations?

Peteronthesouthcoast said:
Completetly agree about insulation. Our building regs were only tighened up last June. All applications which had paid for their building regs fees proir to last June's date are only having to comply with the old regs which were appallingly lax. I am just finishing a project where we have fitted full fill PIR insulation in all walls. These are interlocking "lego" type panels. They come in thicknesses of 90mm, 115mm and 140mm. All are designed to have a 10 mm gap in the wall and are made by all of the big boys under different brands. A warm roof is much more thermally efficient and I recommend those. Scandinavia is the place to look for the way forward.

Glazing is an interesting one. We live in a south facing house, and prior to fitting panels, we absolutely knew that the sun gave us free heat. Panels work at around 20%. With the sun shining we get about 1kw per square metre of glass. Most of that warms up our house. Building regs take the passive U values and are seen as a minus. When orientated correctly they really help. (U values are a measure of thermal efficiency and building regs just look at how much a window will leak heat).

For nearly 30 years I have tried to get people intersted in making sure that new properties have south facing windows and that orientation is included in EPC's as this reflects the real world.

Improving U values in older properties is very expensive as the only sensible option is to to insulate the outside of the building which often conflicts with the roof
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I forgot to mention how thermally efficient our project should be. A 3 bed semi now has an L shaped single storey extension. The back and the side are super insulated. One wall is in common with the neighbour which only leaves the front which is the narrowest wall. The extension is about 145% of the size of the original groundfloor footprint. We are at first fix, but going on what someone else has achieved with a similar project, his heating bills have actuallly come down!!!!!!!
 
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So having a strange day today, just peaked 5.4Kw on the panels for generation, and its caused a power trip, twice.

I did have a power cut a few weeks ago which I had put down to too much load going through the inverter, but have since been told that shouldnt happen anyways.

6.48Kwp on a 6kw inverter, should be able to handle the input?
 
quickshot89 said:
So having a strange day today, just peaked 5.4Kw on the panels for generation, and its caused a power trip, twice.

I did have a power cut a few weeks ago which I had put down to too much load going through the inverter, but have since been told that shouldnt happen anyways.

6.48Kwp on a 6kw inverter, should be able to handle the input?
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The question is what is the specified max solar input power of your inverter.
I'd expect it to be a fair bit higher than the rated AC output of your 6kw inverter (mine is 8kw input on a 5kw AC rated inverter), but is yours?
After that are you within voltage and current input range?
I presume this is your inverter tripping, as opposed to anything in your consumer unit?
 
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SBo said:
The question is what is the specified max solar input power of your inverter.
I'd expect it to be a fair bit higher than the rated AC output of your 6kw inverter (mine is 8kw input on a 5kw AC rated inverter), but is yours?
After that are you within voltage and current input range?
I presume this is your inverter tripping, as opposed to anything in your consumer unit?
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Its the Foxess H1-6.0e so max voltage on the solar is 550V if I read the specs right: https://www.itstechnologies.shop/products/fox-h1-high-voltage-6-0kw-hybrid-inverter-incl-bms

The downstairs RCD circuit broker and the Solar broker both tripped.
 
Inverters only requires RCD/RCBO protection if 1) the wiring requires it for protection (cable buried in wall and not armoured - see BS7671) 2) the inverter does not have integrated DC leakage protection.

It should definitely be upstream of that shared RCD aside the nuisance tripping it is a significant safety risk by leaving the power connected downstream [from the inverter] well beyond the 30ms that the RCD will respond within.

From the instructions:
“This product can cause current with a DC component, where a residual current operated protective device (RCD) or monitoring device (RCM) is used for protection in case of direct or indirect contact, only an RCD or RCM of type B is allowed on the supply side of this product.”

Ie. If it is connected via an RCD or RCBO it must be a type B RCD. Your shared RCD will be type A or type AC. Get the supply to your inverter sorted.

Also from the instructions:
"The end-use application shall monitor the protective conductor by residual current operated protective device (RCD) with rated fault current Ifn≤280mA which automatically disconnects the device in case of a fault. - DC differential currents are created (caused by insulation resistance and through capacities of the PV generator). In order to prevent unwanted triggering during operation, the rated residual current of the RCD has to be min 240mA. The device is intended to connect to a PV generator with a capacitance limit of approx. 700nf."

Ie. The FOX H1 should be installed with RCD protection.
 
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SBo said:
It should definitely be upstream of that shared RCD aside the nuisance tripping it is a significant safety risk by leaving the power connected downstream well beyond the 30ms that the RCD will respond within
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I knew there was also another reason, but couldn't think of it. Very important one that, as an RCD relies on the speed it trips at to save the person's life, adding an inverter will likely render the RCD useless.
 
Ron-ski said:
I knew there was also another reason, but couldn't think of it. Very important one that, as an RCD relies on the speed it trips at to save the person's life, adding an inverter will likely render the RCD useless.
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Yes exactly. The inverter will notice the loss of supply and shut itself down, but it will take a lot longer than 30ms. That whole time someone/something may be getting fried.
 
I've rang my installer (and again after it tripped a second time) and mentioned it tripped when I was using multiple appliances in the home a few weeks ago. They've promised to come back to me.

Hopefully this isnt going to cause me a wider issue, as my installers should have covered load correctly.
 
quickshot89 said:
I've rang my installer (and again after it tripped a second time) and mentioned it tripped when I was using multiple appliances in the home a few weeks ago. They've promised to come back to me.

Hopefully this isnt going to cause me a wider issue, as my installers should have covered load correctly.
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If you attach a pic of your consumer unit then happy to advise what/if any work they need to do to ensure a BS7671 compliant installation
 
quickshot89 said:
pV RCD block is far left, the other block that tripped is the left hand most block with the yellow test button


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URGHHHH BODGE

In no particular order. All of these are in breach of BS 7671.
  1. 16amp MCB is not sufficient for a 6kw inverter. It should be 32amp. No wonder it is tripping.
  2. Supply cable for 6kw should be 4mm or 6mm, that looks like 2.5mm.
  3. Must use EATON devices in an EATON consumer unit, not mix and match (with Hager in this case)
  4. Solar PV MCB must be installed UPSTREAM of the RCDs. It should be in the slot next to the main switch before the first RCD. A new short bit of busbar will be required, presumably what the original installer lacked. This one is dangerous for the reason explained above.
  5. Solar PV should be on an RCBO or MCB+RCD as per the FOX instructions/specifications. I think (not 100%) that this will fit; https://www.edwardes.co.uk/products/eaton-mem-embh132r30c-32a-1p-type-b-10ka-memshield-3-rcbo
 
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Joy :D

Waiting on their phone call back, but assume the fix is

1) Change to have 32amp MCB
2) Check cable is 4mm/6mm
3/4) New CU dedicated for the solar stuff, leaving the house on the primary CU?

The final RCD slot was going to be used to connect up the summer house with power, which in turn has its own small CU to be installed, assume with the above fixed, that shouldnt be an issue
 
SBo said:
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URGHHHH BODGE

In no particular order. All of these are in breach of BS 7671.
  1. 16amp MCB is not sufficient for a 6kw inverter. It should be 32amp. No wonder it is tripping.
  2. Supply cable for 6kw should be 4mm or 6mm, that looks like 2.5mm.
  3. Must use EATON devices in an EATON consumer unit, not mix and match (with Hager in this case)
  4. Solar PV MCB must be installed UPSTREAM of the RCDs. It should be in the slot next to the main switch before the first RCD. A new short bit of busbar will be required, presumably what the original installer lacked. This one is dangerous for the reason explained above.
  5. Solar PV should be on an RCBO or MCB+RCD as per the FOX instructions/specifications. I think (not 100%) that this will fit; https://www.edwardes.co.uk/products/eaton-mem-embh132r30c-32a-1p-type-b-10ka-memshield-3-rcbo
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Nice post :)

I did wonder in regards the 16/32amp thing hence my question but you got there well in advance of my next question and with great details.

Its one of the things I worry about with solar (and many sparks in general it must be said) as to how many just aren't doing this stuff properly!

Its partly why I like my Solax system (although have other issues with in) in that there are no direct connections into the CU, its all before the tails hit the CU and hence the CU cannot be compromised during fitting.
 
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Part P was supposed to stop this sort of shoddy work. The solar guys should have done an installers course and therefore know better. Did they notify building control?

Yes a seperate board is a perfetly good way of doing it, as it using your exisiting board if they just do it correctly. I can't see the meter tails I presume those are above the picture.

For your summer house the installing spark will advise and depends on what you want down there/budget but if you can get armoured cable (SWA) all the way back to the consumer unit that gives you the most options.
 
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SBo said:
Part P was supposed to stop this sort of shoddy work. The solar guys should have done an installers course and therefore know better. Did they notify building control?

Yes a seperate board is a perfetly good way of doing it, as it using your exisiting board if they just do it correctly. I can't see the meter tails I presume those are above the picture.

For your summer house the installing spark will advise and depends on what you want down there/budget but if you can get armoured cable (SWA) all the way back to the consumer unit that gives you the most options.
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Armoured cable already laid before I purchased the summer house :)
 
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