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Example of why plug in solar is going to be a problem
Example of why plug in solar is going to be a problem
This is a brilliant example of why plug in solar is going to be a problem, they are back feeding a ring main, with protective devices that arnt suitable to be used with solar/DC generating equipment. There’s more to think about with electrics and solar than just “will it work”
For context, the RCD isn’t bi-directional, so will only trip on an earth fault on the incoming direction, not if it’s back fed.
It’s also the wrong type rating to be used where there could be DC injection on the system.
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23 Replies
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I have some issuses with how this will be managed.
To meet regulations I have to fit Solar to a dedicated curcuit.
I have to make sue solar is on the correct Breaker, IF an RCD was needed then it was the correct 100 or 300mA rating .
If you “plug in” to a ring final curcuit it is most likely going to need a 30mA RCD to comply due to the manner that the system was fitted.
Undef 3.6kw i can fit and then notify the DNO, any higher then apply before.
Not if the end user had 3.6kw on the roof already and plugged in extra that would then breach the regulations and risk damage to the Network.
And the big one, what stops end users buying 100 of these 800w systems and plugging them in
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I can’t comment on most of this.
But what stops end users buying multiple and plugging them in? Common sense hopefully. But we all know that’s severely lacking these days (hence the don’t drink on bleach and caution hot on coffee cups etc).
No doubt there’ll be a multitude of rules and regs for the construction of these and more for the end user to follow.
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i cant see anything stopping the ends user buying as many as they want
My concerns would be if DNO only approve a 3.6kw inverter so the end user buys 10 of these plugs ins so they can fill the space…..
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How has Germany managed this problem?
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Scare mongering. Most homes don’t even have bi directional RCBO’s on big systems let alone little 800w ones!!
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how is this scaremongering?
As for the “little 800w ones” if you were on any of the groups discussing plug-in solar most change the settings to give 1200w and no-one ever has one – I’ve seen posts talking about 5 or more plugged in.
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Because as most people with solar don’t have bidirectional RCBO’s let alone with these tiny systems. Also someone posted all installs prior to 2019 didn’t have bi directional RCBOs.
Hager for example only have had bidirectional RCBO’s for the last 2 years, and only sold in a few outlets.
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most RCBO’S in domestic properties are not suitable for Solar anyway.
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systems installed prior to 2019 required to comply with the regulations in force at the time. If there was subsequent work done at a later date then they require to update to meet the new regulation. Failing to do so leaves you at risk of your household insurance being invalidated and all electrical work being deemed unsafe by the local planning department or other enforcement.
My house fully complied with the regs when it was built in the 1940’s and if it remained unchanged then there was no requirement to upgrade to new regs. However when an extension was done in 2000 the new regs applied an all wiring needed to be brought up to spec – that was a lot of work. Again, nothing else would have been required if no other work was done, however in 2020 I did more work so the newer regs came into force and other changes were required.
The fact that “things work” is irrelevant. You only have to look at simple things in this group where people say “you don’t need bird protection” until you do and by then it’s too late.
As for these being “tiny systems” you need to understand these devices are supposed to be restricted to 800w, but every one of them can be changed by the user to 1200w – and this is recommended on every plug in solar group I’m on. Also people are plugging in multiple devices (I’ve seen 5 or more being plugged in) so that’s a 6kw – Full DNO G99 Pre-approval system being plugged in by someone who knows no better.
Let’s keep it safe. Err on the side of caution and reference the regulations. Failing to do so will result in unnecessary and unforeseen risks, which won’t become a problem until it does, and by then it’s too late
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My understanding is that only the new work has to meet the new standards.
Stuff which is pre existing and unchanged has to meet the standards in force at the time.
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How does the rest of Europe (via Lidl etc) do it without burning down?
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european use radial circuits not ring mains. Inverters don’t meet the disconnection times for rcd protection, thus risking electric shock which could prove fatal! Not scare mongering just fact!
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how do you know they will not meet the disconnect times… tried & tested it?
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Of course he hasn’t. You’d think inverters were designed by FB experts and not actual electronic and power engineers with experience in this field – I mean some folk have a roof full of the blighters…
The important thing to remember is that it’s “change”, folk hate change.
Whether it’s banning fags, banning lead in petrol, removing CFC’s, changing to EV’s or in this case “plug in solar” – they’ll look for anything they think supports the reason they think it shouldn’t happen.
I can’t think of anytime where change was mentioned when there wasn’t a backlash.
In this case you’re also going to get backlash from folk who think that people with plug in solar are freeloading when their systems cost upwards of 10k.
If theirs cost that much why should people benefit for a couple of hundred quid?
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Some of us don’t even have RCDs so not a problem
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Please explain how a typical inverter can put dc feedback on the mains input. If the mosfets fail they’ll shut everything down.
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it’s dc ripple that’s the issue. The DC blocks the AC tripping mechanism. You’ll always get leakage
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What rubbish , 800 is max plug in , ,,,, you might top 600 w ? in July ,( FYI : 1kw solar produces about 4 amps ) think about it
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If I read and understand my washing machine manual it back feeds a bit as it uses motor regen when slowing down to save a bit of energy so get a better efficiency rating
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no, it on runs. But if it’s a DC inverter drive It will give DC feed back, and the manual will probably say some were “ensure correct overload protection type and size is fitted”
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Everyone, espescially uk electricians forget that the whole of Europe has plugs and sockets that can be inserted either way round so the live could be on either pin depending on how the plug is inserted. When the mains turns off the inverters shut down.
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I’d never do it for the sake of my own safety
It’s cheap enough to install an additional circuit for the sole purpose of plug in solar although I’d always hard wire it via isolator switch
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All of the 4kw FIT solar systems that went in before closure in 2019, mine included didn’t use bidirectional devices, also those right up until they started being installed due to new regs, so I don’t really think ‘it’s going to be a problem’ too much, but it is going to be interesting this plug in solar.
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