Posted by: @jamespa

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is this a UK specific problem which has been shown to occur with plug in solar devices,

The issue I was referring to in that geographical area was for fixed solar-inverters, not plug-in kits.

I've just checked online (using my rudimentary German and Google Translate) and found that their plug-in solar kits come with a special 16A plug.
They don't get plugged into the ordinary household sockets.

Since there are lots of different power socket 'standards' across Europe, I would expect the regulations to vary depending on the country.

Posted by: @transparent

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I've just checked online (using my rudimentary German and Google Translate) and found that their plug-in solar kits come with a special 16A plug

16A sockets (and therefore plugs) are, I think, the 'power' standard in Germany, as in several EU countries that use radial wiring without fuses in the plug. 

Are you saying that they have to be fitted on a specially provided circuit or merely that the plug itself is special?  if the latter then, so long as it is moulded on, its part of the installation.

I found the below here (suggesting that there was a point in time, (up till March 2025), where a special socket was needed but that has now gone away) but I dont know if its reliable

"Initially, DIN VDE 0100-551-1 (2018) permits “plug and socket” connection of micro-generators if they used a special  energy feeding connector – which in practice means using a Wieland Einspeisesteckdose (Wieland feed-in socket) or equivalent. This was widely criitzied and the updated pre norm or draft norm gives a standard connector as one of the possible connections.

The VDE’s recent position paper explicitly “dulds” (tolerates) Schuko for these devices . Virtually all plug-and-play kits now ship with a Schuko-type plug for convenience, since it allows non-experts to install without an electrician."

PS

This appears also to say that Schuko sockets are now allowed, Schuko being, I believe, the standard 16A 2 pin plus earth socket found in much of the EU.

It feels to me like the Germans may have cracked it and Germany is hardly a country renowned for lax safety standards!  If we ban it or require excessive regulation I am now definitely minded to suspect its industry protectionism, British Exceptionalism or NIH.  As always I remain open to being convinced otherwise, its just getting more difficult!

Further to the above DIY plug in solar (German - Balkonkraftwerke) is offered by IKEA in Germany

Scrolling down it says

"DIY Installation, ohne professionelle Hilfe."

For many it wont need Google translate to work out what that means, but for those with no German 'ohne' means without and 'Hilfe' means help.

EUR999 for 4*450W plus a 1.9kWh battery, less 15% discount if you are an IKEA family member

Posted by: @transparent

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It's the other way around @batpred 

Newer RCDs and RCBOs are most likely to have a small solenoid with the coil being energised via a control circuit board.

...

Please re-read my description on the earlier topic about RCBOs to understand why there is a risk of the small solenoid coil remaining energised if the device has been used on a circuit supplying a source of generation.

I had a read and I still cannot understand the below. We are talking about the direction of power flows. The direction of the current changes direction 100 times a second. So as I said, the issue cannot be about the direction of the current. 

But if there is power still being applied in the reverse direction by an inverter or storage battery, when the contacts open, the solenoid remains energised.

If it is about DC currents, why not describe it as such. 

It does seem the Beama originated confusion was related to a British labelling standard.. 

If the Germans found a socket adapter is sufficient to fix this (which I would not be surprised if a filter for DC is already built into many such DIY kits), why do we need to mandate such an intrusive replacement of an RCD on a board? Do we not have good 'infra' (courts, police, etc) to deal with uninformed or reckless sales of electrical equipment? Are consumers here not to be trusted to use the solar panels as per instructions? I really hope we do not need an MCS facade..

The thing is that gas does not suffer from such complicated concepts yet it is deadly in many ways.. 

Posted by: @batpred

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We are talking about the direction of power flows...

We're talking about the direction from which the power could potentially flow.

The RCBO has two sources of electrical energy applied to it – the grid and the micro-inverter.
When the contacts open, the grid can longer energise the solenoid coil.
But the inverter can do so if the RCBO is the usual/common uni-directional device.... and the inverter is faulty or not working in compliance with G98.

Posted by: @batpred

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If it is about DC currents, why not describe it as such.

Because it's not about DC currents.

It's about the solenoid coil remaining energised by the inverter after the contacts have opened.

That's a fault condition.

Posted by: @batpred

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It does seem the Beama originated confusion was related to a British labelling standard.. 

Not so.

The labeling on a uni-directional RCBO shows the Load-side Live and Neutral terminals.
There was no confusion.

The bi-directional RCBO units have different markings, but there is no requirement for such a label to remain visible to the householder once the cover is placed on the CU by the electrician.
Nor is there a 'standard' symbol to denote a bi-directional RCBO.

Posted by: @batpred

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If the Germans found a socket adapter is sufficient to fix this [...]

They didn't.

Their regulations simply required a 16A two-pin plug with an earth bar to be pre-fitted to the Balcony Solar kit when it is sold to the public.

Posted by: @batpred

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[...] why do we need to mandate such an intrusive replacement of an RCD on a board?

The amendment to the 18th Edition of the Wiring Regulations was made in order to facilitate the earth-leakage protection continuing to be effective.
That's what the householder would expect if they've had an RCBO fitted to a mains circuit.

The Amendment needed to be issued for safety reasons.... and applies to a circuit which connects generation/storage apparatus.

It wasn't deliberately intended to make it difficult or expensive to install a Balcony Solar kit.

Balcony Solar kits could indeed be sold in the UK if home-owners connected them to 13A sockets which were supplied from the Distribution Board via

1. a wired fuse
2. an MCB
3. an MCB fed from an RCD
4. a bi-directional RCBO

but not a socket supplied from a uni-directional RCBO.

So how could you safely convey that message to the general public?

Posted by: @jamespa

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16A sockets (and therefore plugs) are, I think, the 'power' standard in Germany, as in several EU countries that use radial wiring without fuses in the plug. 

Yes, this is the most common. Some places have male earth pins in the sockets but the plug was standardised in that shuko socket over 30 years back I think. There may be the odd country with a different type. And there are/were old style sockets for low power stuff that does not need earthing. 

Anyway, could all this confusion about bidirectional rcbos have been maintained without knowledge from MCS? Gosh, just a few years away from the EU and the exceptionalism grew with a vengeance. Clearly i was wasting my time when looking for these rare bidirectional rcbos! Sorry if I misled anyone. 

Unsurprisingly, the international iec electrical standards association do not seem to care much about this whole topic of unidirectional rcds for alternating currents. 😂

The sooner ISO or another org takes over this, the quicker we get to common sense... 

No wonder we could entertain the idea of the specially programmed sockets for car charging. 

Posted by: @transparent

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Balcony Solar kits could indeed be sold in the UK if home-owners connected them to 13A sockets which were supplied from the Distribution Board via

1. a wired fuse
2. an MCB
3. an MCB fed from an RCD
4. a bi-directional RCBO

but not a socket supplied from a uni-directional RCBO.

So how could you safely convey that message to the general public?

There is no such thing as an unidirectional RCBO. An AC current changes direction 100 times a second. 

If there is a device that filters DC, why not call it that? 😉

In fact, there are rcbos that trip with DC currents that should not occur as well. 

Obviously, Proteus created that bi-directional arrow. Which helps to make it seem a unique product! Sales people. Is this a commercial topic? 😂

Posted by: @transparent

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The RCBO must still trip-out.

It does so, not because of the amount of DC component, but because there is a fault with the equipment.

If RCBOs only needed to trip when an inverter behaved as its G98 certification says it should, then it's a pretty useless safety device!

We may need to check where the g98 would mandate an RCBO .. and I cannot think why. Would a type certified inverter not handle filtering of DC currents? 

Could you be referring to another trip of safety device, @transparent ? 

I only used g99 forms and do not remember such topic there..  

Sorry guys but I'm still not understanding why it's sufficiently safe in Germany that Ikea can sell DIY plug in solar, but not sufficiently safe in the UK.  There is no reason why anyone who is not advising Government should know, but it would be good to know for certain that nobody here does know!

What am I missing?  Is this a Brexit freedom for electrons?

Posted by: @jamespa

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Sorry guys but I'm still not understanding why it's sufficiently safe in Germany that ikea can sell DIY plug in solar, but not sufficiently safe in the UK.

😂

I remember IKEA also struggled to get their kitchen lighting accepted here.  But I think that was just that the electricians wanted to protect their exclusive access to that part of our homes.. 

Beama seems to have got a cushy arrangement with these unique rcbos, how can we help accelerate their demise? I really have no idea whether MCS had any hand in this. 

@editor I think you wanted to re-awaken this thread.  My personal view is that it has re-awoken with a vengeance and has become very technical. 

However I think a fair summary for the relative layman is:

• There are some risks in theory with plug in solar (as there are with absolutely anything we do).  These may or may not be significant in practice.
• DiY plug in solar is legal in several countries, for example IKEA sell it in Germany (and I believe several other EU countries)
• Nobody on here has so far been able to explain why something that is sufficiently safe in Germany (not exactly lax in its application of safety rules) is not also sufficiently safe in the UK.  The risks are obviously in principle identical, subject to any differences in wiring practice that materially affect these specific risks.
• This inevitably leads to a suspicion that there is industry protectionism, British exceptionalism or NIH involved. 
• The suspicion may yet prove to be unfounded.  To show that it is unfounded those who are opposed to plug in solar would need to identify a material difference in electrical wiring practice which triggers a risk here but not in (eg) Germany.  It is not sufficient just to say 'our wiring is/regulations are different'.

My personal opinion, which others may not share, is that the burden of proof now lies principally with those who would oppose, not those who would permit.  Put another way, if its good enough for German regulators, its good enough for me unless there is a specific reason for the UK being different.  However this opinion is purely personal.

Hopefully someone will enlighten us on whether there are differences in wiring practices that materially affect the risk (and if so how), or alternatively confirm which of industry protectionism, British exceptionalism or NIH is at play.

Posted by: @jamespa

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...

My personal opinion, which others may not share, is that the burden of proof now lies principally with those who would oppose, not those who would permit.  Put another way, if its good enough for German regulators, its good enough for me unless there is a specific reason for the UK being different.  However this opinion is purely personal.

...

My take is a slight variation to that.

I don't necessarily think we should implement unless we can prove there are significant risks; I think we should instead be making the decision to implement anyway and then working through any risks to decide how to resolve them; in essence, a process of "taking away reasons to fail". Once again, though, my own opinion and others may vary.