OLEV Installation Auditor problems

Sparkingchip said:

Whilst I accept that the introduction of SPD and AFDD is not driven solely by "those with a vested interest" such as manufacturers, the manufacturers are not doing anything to promote the benefits of having these devices to the general public,  they once again seem to be relying on electricians to do the promotion for them, with electricians being left in the position of having to enforce any requirements to have them.

I can definitely see that perspective.

I think the manufacturers may well have a job explaining the role of the SPD, at least, to the general public ... and the reason they are now necessary, whereas back in the 1970s and 1980s we would never have dreamed it would be beneficial.

You only have to look at who sits on the wiring regs committee to find the answer to these questions. I suspect that those who also sit but who are not manufacturers are being rather coy about the degree of influence that manufacturers have over the introduction and drafting of any new regulations.

I rather suspect that both spds and afdds are of highly dubious value, since there would appear to be no evidence to the contrary that I am aware of. Indeed, both appear to be looking for problems to solve which do not really exist to an extent whereby their use and expense are wholly justified, especially in a domestic setting.

Back on topic. Who actually conducts these OLEV audits? And more importantly, who appoints them and on what criteria?

Or to put it another way, if I wished to become an auditor of such installations, who would I contact and what would I need to be successfully appointed?

And who sits on the JPEL/64 committee and in what capacity? Moreover, who else do they represent in their 'day jobs'?

OK. So is there any data or statistical analysis available for the need for such devices. If not we just accept the changes are made for us with no idea why. We all know the risk assessment for spd's is nonsense and afdd's only just have some benefit. But how much? I have no idea and being at the sharp end selling something I have little faith in leaves me cold.

The single dwelling unit exemption is rather subjective. Who decides whether or not protection is justified? Presumably the customer.

From memory, I think guidance suggests that if the value of the installation protected is less than 5x the cost of the SPDs then it's reasonable to claim they're not justified. Just a rule of thumb of course, but something of that ballpark.

The risk assessment in 443.5 is, IMHO, not fit for purpose and it will be interesting to see what next week brings. What I want to know is: (1) the chance of a significant overvoltage over say, 5 years; (2) the chance of it leading to damage; (3) the cost of protection; and I can work out (4) the value of the equipment to be protected myself. To justify protection, (1) x (2) x (4) needs to be higher than (3).

Even if (3) is very low (especially if a new CU is being fitted), the cost is not necessarily justified.

I'd certainly agree that the RA isn't at all clear about how it works - I especially find the 10x difference between 'urban' and 'suburban' and no difference between 'suburban' and 'rural' very curious. Also I'm still not sure whether the cable lengths are meant to cover just the cable that runs directly between the installation from the source, or the whole network (including that downstream of where my installation is tee'd off from the main) - if it's the cables acting as an "aerial" you would have thought it would be the latter, but examples seem to  imply the former, and the wording seems unclear.

I'm in two minds myself. In the last 10 years or so, I've had one boiler PCB go phut, another part of the boiler with electronics in it go phut, twice, an ADSL modem start misbehaving and need to be replaced, and the ballasts of several LED fittings fail, one RCBO and a CCTV camera. Some of those did seem to be about the time we had thunderstorms or when the distribution cable in the street went bang. Now whether any of that could have been prevented by SPDs I don't know. But if even half or a third of those failures could have been prevented, it probably would have been well worth while financially, and more so from a convenience point of view. If I were to add £20k or £30k of EV packed with electronics to the system I might well err on the side of safety as it were.

I'm been mulling over installing SPDs just to see if they make a difference. The difficulty I have is that I have 'entry points' all over the place - Electric enters in the cellar, Phone & TV at 1st floor level and PV through the roof. Had I thought about SPDs when originally designing everything I might have tried to bring everything in through a common point, but it's too late for that now. I have a fear that doing half a job (e.g. SPDs on the mains but not phone/TV/PV) could actually make things worse rather than better (I had a bad experience years ago with surge-protected PC with a modem and an unfortunate PBX), so it's all still on the 'things to ponder' list.

   - Andy.

Manufacturers should install Voltage surge preventative devices in their equipment if that can be damaged in service. It would not cost much.

cpc.farnell.com/.../PL10022

Z.

Agree Zoom, problem is; they prefer to transfer the risk to the installer instead.

Personally, I don't think that the VORs fitted in domestic consumer units are really up to the job in any case. To me it's akin to sprinkling glitter on a turd simply because you can't polish it. If there really is a high risk of a spike in the external supply, then that is where the prevention measure should lie and not after the fact.

My idea of integral appliance S.P.D.s or extension lead surge protection is scuppered by 534.1 Note 1 apparently. But there again, what does "does not take into account" mean there?

Z.

I have seen some large bull horns spark gaps on a pole transformer locally to short lightning strikes. But I don't think that they are very sensitive and may well let some damaging Voltage through to local houses.

It's the usual tactic, they've purposely made it a fuzzy catch-all area to introduce confusion whereby it is easier to just comply rather than question. If you don't question you don't know, and they don't like awkward questions.