What will happen if my SPD activates?

I have to agree with you @JohnW2 I watched the video about need for type B RCD and SPD and in both cases not convinced.
Unless/until someone can shows us some decent evidence, I don't believe that any thinking person could be particularly convinced in either case.

Indeed, there isn't really much/any hard evidence that even RCDs save a significant number of lives, yet most people seem have somehow been convinced that they do!
However not convinced on the need for all the 30 MPH speed limits either, because some does 80 in a 40 limit and has an accident is not reason why it should be reduced to 30.
That's a bit different, since it's just a matter of arbitrary decisions about 'thresholds'.

There's plenty of evidence that slower speeds result in less deaths and a reduction in the severity of injuries, and also evidence that lowering the speed limit results in a 'general' reduction in driving speeds (even if not all people obey the limits), so it's really down to just the essentially arbitrary decision as to where 'to draw the line' - and that decision has to be a balance involve many considerations - imposing and strictly enforcing a national speed limit (including motorways) of 5 mph or 10 mph would undoubtedly have a major impact on deaths and injuries, but would obviously be totally impractical.

Kind Regards, John
 
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My electrician wrote SP in faint pencil on several blanked MCB slots which I knew were spares - fair enough. Then I saw SPD in ink under the slots next to the main switch. Why the extra D, I thought. So I did a bit of research and then remembered that the estimate for the CU included surge protection. Being on a forum like this can be immensely educational. Still trying to understand MΩs properly although I know what it stands for.
 
Indeed, there isn't really much/any hard evidence that even RCDs save a significant number of lives, yet most people seem have somehow been convinced that they do!

I agree. I see no need for most people to fit SPD at all, though there might be some locations where they offer an advantage. RCD's fitment has to be be balanced, the risk of electrocution, against the physical risk of a sudden trip leaving everyone in the dark. An older installation, I fitted them providing protection for all of my outdoor sockets and work benches, where their is a very real risk.
 
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RCD's do not stop you getting a shock when you touch some thing live, all they do is reduce the time you get the shock for, what we hope is they trip before we touch some thing live, which means in the main they protect from contaminated water passing current. But we can see where they help, we remove a socket after a trip and see the water in it, without it tripping it could have causes a fire.

But point is we do see where they have operated for good reason.

The SPD however we see nothing, same as filtered sockets, we have no idea if even some thing in the box. And why some are £30 and others £130 seems a mystery. Yes an RCBO varies in price from £12 to around £28 but £30 to £130 is a massive jump.

If the videos singing the praises of SPD showed the oscilloscope pattern before and after that would help, but pictures like this
upload_2021-11-19_10-40-59.png
with a claim that a SPD would have stopped it. I can not see how a SPD would have absorbed that.

However the question is what is the negative side to SPD, and the only negative is price, with RCD negative side is loss of power, so careful consideration is required. But with a SPD is designed to fail open circuit, so if not sure fit one.

However my fusebox CU came with a SPD fitted and no overload device for the SPD other than DNO fuse, latter boxes I see have a MCB to supply the SPD, which does mean the MCB has a resistance between SPD and supply, so it may not work as well.

With a RCD we talk about milliseconds must trip in 40 mS but with SPD we are looking as microseconds, not even sure if an oscilloscope would show it.

What we seem to be looking at is the use of LED lights and the risk of failure with a surge, since we can't other than fitting a SPD work out if a surge will cause the LED to fail, and unlike LED failing due to power cut where the emergency lights if fitted will work, a surge can take out the emergency lights as well, as also LED powered.

The other point is EV charging points with loss of PEN detection, the electronics which detect the loss of PEN can be damaged with a surge, so should be SPD on a feed to the EV charge point.

The same of cause with fire or smoke detection, electronic equipment so a surge could stop it working, so if that fails it would be dangerous, so with solar panels, fire alarms, and EV charging systems in the home with an EICR lack of SPD could be considered as a C2.

The point is many manufacturers as stipulating SPD before warranty is valid.

To my mind an emergency light likely the battery will act as a surge protection, but we don't know.

It seems for a single occupancy domestic installation SPD is not required, so can't see how you can code lack of SPD, however if a semi-detached house or even has a granny flat, would it be single occupancy?
 
RCD's do not stop you getting a shock when you touch some thing live, all they do is reduce the time you get the shock for, what we hope is they trip before we touch some thing live, which means in the main they protect from contaminated water passing current. But we can see where they help, we remove a socket after a trip and see the water in it, without it tripping it could have causes a fire.

But point is we do see where they have operated for good reason.

The SPD however we see nothing, same as filtered sockets, we have no idea if even some thing in the box. And why some are £30 and others £130 seems a mystery. Yes an RCBO varies in price from £12 to around £28 but £30 to £130 is a massive jump.

If the videos singing the praises of SPD showed the oscilloscope pattern before and after that would help, but pictures like this View attachment 251193 with a claim that a SPD would have stopped it. I can not see how a SPD would have absorbed that.

However the question is what is the negative side to SPD, and the only negative is price, with RCD negative side is loss of power, so careful consideration is required. But with a SPD is designed to fail open circuit, so if not sure fit one.

However my fusebox CU came with a SPD fitted and no overload device for the SPD other than DNO fuse, latter boxes I see have a MCB to supply the SPD, which does mean the MCB has a resistance between SPD and supply, so it may not work as well.

With a RCD we talk about milliseconds must trip in 40 mS but with SPD we are looking as microseconds, not even sure if an oscilloscope would show it.

What we seem to be looking at is the use of LED lights and the risk of failure with a surge, since we can't other than fitting a SPD work out if a surge will cause the LED to fail, and unlike LED failing due to power cut where the emergency lights if fitted will work, a surge can take out the emergency lights as well, as also LED powered.

The other point is EV charging points with loss of PEN detection, the electronics which detect the loss of PEN can be damaged with a surge, so should be SPD on a feed to the EV charge point.

The same of cause with fire or smoke detection, electronic equipment so a surge could stop it working, so if that fails it would be dangerous, so with solar panels, fire alarms, and EV charging systems in the home with an EICR lack of SPD could be considered as a C2.

The point is many manufacturers as stipulating SPD before warranty is valid.

To my mind an emergency light likely the battery will act as a surge protection, but we don't know.

It seems for a single occupancy domestic installation SPD is not required, so can't see how you can code lack of SPD, however if a semi-detached house or even has a granny flat, would it be single occupancy?
I see a lot of crap written on this forum and quite often a long post like this one of Erics will contain some good points and some rubbish.
Not this time well apart from telling of the rubbish like some CU's require the SPD for a warranty, surely that's just a get clause for the manufacturer.
No that pic would undountedly not had been stopped by the SPD. If that was a surge I imagine the SPD would have done that itself and/or made the bang worse. However I suspect the big bang was more to do with a bad joint and a short circuit. Just my opinion as there is virtually nothing in a cutout that would be affected by excessive voltage!
 
I agree. I see no need for most people to fit SPD at all, though there might be some locations where they offer an advantage.
I have to say that I have yet to be convinced that there is a 'need' for anyone, in any location, to fit them - or, at least, for them to be 'required' to fit them. One really has to scrape barrels to think of ways in which the lack of SPDs could present any risk to 'life and limb' and, as for risks to equipment, I would say that should be a personal choice. Particularly if the theoretical risk could be supported by reasonable (and quantified) evidence of a significant real-world risk, I would say that people should simply be informed of that potential risk to their equipment and then left to decide whether they wanted to install something which might (and I'm not sure about the evidence for this, either) reduce that risk.

As far as #regulations' like BS7671 are concerned, this seems to be a fairly unique 'requirement', in that it does not seem to be directly related to eiether electrical dangers or house/building fires.
RCD's fitment has to be be balanced, the risk of electrocution, against the physical risk of a sudden trip leaving everyone in the dark. An older installation, I fitted them providing protection for all of my outdoor sockets and work benches, where their is a very real risk.
There are, of course, theoretical risks ('to life and limb') which the presence of RCDs/RCBOs will reduce, to at least some extent. However, it is essentially impossible to quantify how much death and injury has be avoided/reduced as a result of them.

In terms of domestic electrocutions, there were (rather surprisingly) so few of them in the UK even before we had RCDs that there was never scope for any major reduction due to RCDs (even total abolition of domestic electrocutions would only have been equivalent to loss of a week of two's road deaths per year), and such 'abolition' was never going to be possible .... and, again, that has to be balanced against the cost (I think 'many billions') that has been spent on RCDs and their fitting in recent decades.

Kind Regards, John
 
RCD's do not stop you getting a shock when you touch some thing live, all they do is reduce the time you get the shock for, what we hope is they trip before we touch some thing live, which means in the main they protect from contaminated water passing current.
All true.
But we can see where they help, we remove a socket after a trip and see the water in it, without it tripping it could have causes a fire.
I seriously struggle to imagine that current through 'water in a socket' would ever cause a fire.
If the videos singing the praises of SPD showed the oscilloscope pattern before and after that would help, but pictures like this ... with a claim that a SPD would have stopped it. I can not see how a SPD would have absorbed that.
Quite so. There is a theoretical basis for believing that SPDs might possible result in some reduction in damage to equipment (but I still can't find anything approaching 'chapter and verse' about this) but, I have recently written, one needs to think in terms of incredibly improbable circumstance for them to significantly reduce the risks of electric shock and/or fires. I'm not saying that they don't, but I've yet to see evidence that they do )or indeed, that there is a significant 'problem' for them to address) - and that is a bit of a problem for me, since I've spent most of my life working in highly 'evidence-based' disciplines.

Kind Regards, John
 
Particularly if the theoretical risk could be supported by reasonable (and quantified) evidence of a significant real-world risk, I would say that people should simply be informed of that potential risk to their equipment and then left to decide whether they wanted to install something which might (and I'm not sure about the evidence for this, either) reduce that risk.

I have lost just two items attributable to surge in 50 years. One an extremely expensive steerable dish satellite system and a PC card modem, both simultaneously and due the EMP to a close lightning strike. The local exchange also suffered damage, probably from the overhead lines. I doubt an SPD would have made a jot of difference.

3 weeks ago, my modem failed, as did the doodah at the exchange, again I doubt an SPD would have made any difference.
 
In terms of domestic electrocutions, there were (rather surprisingly) so few of them in the UK even before we had RCDs that there was never scope for any major reduction due to RCDs (even total abolition of domestic electrocutions would only have been equivalent to loss of a week of two's road deaths per year), and such 'abolition' was never going to be possible .... and, again, that has to be balanced against the cost (I think 'many billions') that has been spent on RCDs and their fitting in recent decades.

Back in the late 80's, I was involved with a major water supply project, which involved several engineers working in a massive underground basement - a cavern of a place, installing some massive pipes, pumps, motors and etc.. Other 110v lighting fed from a very large mains powered transformer, it would have been total blackness even in the middle of the day, lots of sumps, trip hazards and etc..

RCD's were fairly new and the site manager insisted on one being installed by the electrical contractor and the site itself was out in the wilds of Yorkshire, far from adequate mains supplies, with a proper supply not due once it was near finished. Several times a day the RCD would trip out, leaving guys the middle of manhandling tons of equipment in sudden and complete darkness. The responsible electrical contractor was unable to find a cause of the tripping, I agreed with his diagnosis so all I could do was tackle the site manager to try to persuade him that the constant tripping was more of an H&S risk, than doing away with the RCD. I failed and ended up supplying everyone with a torch.

Sometimes the cure is a much greater risk than the disease.
 
I have lost just two items attributable to surge in 50 years. One an extremely expensive steerable dish satellite system and a PC card modem, both simultaneously and due the EMP to a close lightning strike. The local exchange also suffered damage, probably from the overhead lines. I doubt an SPD would have made a jot of difference.
Quite so. Equipment failures chronologically associated with lightning are probably due to 'spikes' in the supply caused by the lightning, and I don't think anyone pretends that SPDs are very likely to protect against such events. In any other situation of electronic equipment failure, I can't see how one can ever attributer it to power supply 'spikes/surges' with even a tiny amount of confidence. As you go on to say ...
3 weeks ago, my modem failed, as did the doodah at the exchange, again I doubt an SPD would have made any difference.
Again, I'm inclined to doubt it, too, not the least because I don't even know what caused those failures. Despite having had countless of them over the decades, I have only extremely rarely experienced 'premature/unexplained death' of anything electronic - so I can certainly be sure that I, personally, have not experienced enough such failures 'due to spikes/surges' (since I have not experienced much from any cause) to represent a problem to which I would like a solution!

I'm intrigued by the way in which some people seem to have dramatically changed their views. You only have to go back a small number of years in the archives of this (or similar) forum to see that any mention of any sort of 'surge protection' resulted in widespread ridicule and talk of ';wasted money', 'charlatans' and 'snake oil'. I agreed with those responses then and, speaking personally, nothing has yet convinced me that I need to change my view!

Kind Regards, John
 
... Several times a day the RCD would trip out, leaving guys the middle of manhandling tons of equipment in sudden and complete darkness. The responsible electrical contractor was unable to find a cause of the tripping, I agreed with his diagnosis so all I could do was tackle the site manager to try to persuade him that the constant tripping was more of an H&S risk, than doing away with the RCD. ... Sometimes the cure is a much greater risk than the disease.
Quite so.

Kind Regards, John
 
Quite so. Equipment failures chronologically associated with lightning are probably due to 'spikes' in the supply caused by the lightning, and I don't think anyone pretends that SPDs are very likely to protect against such events. In any other situation of electronic equipment failure, I can't see how one can ever attributer it to power supply 'spikes/surges' with even a tiny amount of confidence. As you go on to say ...

I should have mentioned, it was the LNB and antenna inputs (RF side) which suffered, the unit and processor display etc. continued to function, so not a mains spike. Likewise the modem, only the phone side failed, it still worked so far as the PC was concerned.

Three weeks ago, exactly the same.
 
I watched the John Ward, Kirsty Johnson and Paul Meenan video it is a long video, and I must admit there were some points which did seem to make sense, but some like the picture I put up did not, and some went over my head.

A few months ago I would have said SPD is not required, but I see on this forum reports on LED lights failing, yet, touch wood, I have only lost one while living here, LED lamps seem to be reported on here as failing more regular, I will now ask if a SPD is fitted to those who report loss of LED lamps now.

The video seemed to be more about industrial premises, but I was left undecided. Has anyone else watched the video?
 

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