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Where to buy nylon screws?

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HappyHippyDad

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I want to replace some metal socket screws with nylon screws.

I can only find 25mm ones. I really need a selection, at least 35mm i would think, preferably a few 40mm ones as well.

If they are impossible to find, then I guess I could use the extenders, but I'd much rather have a selection of varying sized nylon.

Does anyone know where to purchase them?
 
10.7. It should be noted that the protective measure double or reinforced insulation is only applicable to electrical installations or circuits therein that are under effective supervision in normal use to ensure that
no change is made that would impair the effectiveness of the protective measure (regulation 412.1.2). Domestic and similar premises falling within the scope of this Guide cannot be considered to be under effective supervision.

I think this is a non-argument?
 
10.7. It should be noted that the protective measure double or reinforced insulation is only applicable to electrical installations or circuits therein that are under effective supervision in normal use to ensure that
no change is made that would impair the effectiveness of the protective measure (regulation 412.1.2). Domestic and similar premises falling within the scope of this Guide cannot be considered to be under effective supervision.

I think this is a non-argument?
I genuinely think there are flaws whichever way we turn on this if a rewire isn't affordable at that moment in time. I also think we'll never all agree!

In a nutshell do we say that even though the old regs allowed omission of something that the new regs require, we should avoid making it a bit safer because another new reg uses "adequate supervision" as one example of how to make sure the installation isn't modified, even though the best practise guides suggest making it a bit safer as the 2nd choice last resort (3rd choice being risk assessment)

Modern regs require things old regs didn't. Modern regs also clearly say that older installations to older regs aren't necessarily dangerous. We say the regs are retrospective often enough. So anyone inspecting makes a judgement call on this and says not complying with this newer reg requiring a cpc makes it potentially dangerous.

We then have dear BPG4 relating to domestic eicr's pointing us to BPG1 regarding this issue, which starts off talking about homes not needing a cpc in lighting circuits once upon a time, goes through the hoops of what to do, and finally says in 10.7 'by the way don't do this in homes'.
But then read on - even more amusingly it goes on in 10.8 to say what to do if you reconnect one:

10.8. Subject to the recommendations of Section 10.3 to 10.5 (NOT 10.7) of this Guide being met, where lighting circuits having no protective conductor are connected to a new consumer unit, it is strongly recommended that a warning notice with black letters on a yellow background should be fixed on or adjacent to the consumer unit

Bottom line for me, if a month after I was at a property the live dropped out of a fitting and someone died changing a bulb I'd probably wish I'd ignored one interpretation of 412.1.2 and I'd put a class 2 fitting in. If they change it back, good luck to them, but I'd sleep better knowing I'd done my bit by explaining why a rewire is needed, and doing the best for them in their current situation.

Finally, genuine question - Even though RCDs are deemed additional protection, would having one on the circuit do anything to appease 412.1.2 which starts off "Where this is to be used as the sole protective measure....."
 
Class II cannot be used as a means of protection in a dwelling. If I had a fiver for every time I said this, I follow BS7671 and not Guides and whether the client cannot afford any rewiring which is necessary is not my concern.
Keep saying it Westward.

I have been one to grudgingly accept, and on 2 or 3 occasions, implement, the guidance given in BPG 1, for the reason that some clients just cannot afford to rewire the lights circuits.

I'm beginning to rethink this...
 
@happyhippydad hasn't stated if this is for remedials in response to an EICR, but let's assume it is. To summarise:

1 - No CPC on a lighting circuit does not comply with requirements for the protective measure:ADS in BS7671 (411.3.1.1), so warrants a code on an EICR.

2 - (assuming domestic) You can't say that the circuit complies with the requirements for the protective measure:double or reinforced insulation (412.1.2 and 412.2.3.2), it still warrants a code. This is noted in BPG1.

3 - RCDs can't be used in place of the above protective measures (415.1.2), so it definitely does not comply and needs coding.

4 - BPG4 issue 5 offers as an example : C2 Absence of a circuit protective conductor for a lighting circuit supplying items of Class I equipment, or connected to switches having metallic face plates.

However,

5 - BPG4 also offers: C3 Absence of circuit protective conductors in circuits having only Class II (or all insulated) luminaires and switches. It also references BPG1 where there is more guidance on the issue.

6 - If you trust the guidance in the BPG's, then it is possible that a lighting circuit without a CPC may still return a satisfactory outcome on an EICR.

7 - It seems many of the major industry bodies have put their names to the BPG's, so I personally assume the guidance carries some weight. Others disagree with me on this, and no one can prove either way as it is a matter of opinion. Code how you see fit.

8 - The End.
 
Your item 5 cannot be considered in a dwelling according to BS7671. I am sure these Guides have a large brain pool behind them but nevertheless Class II should not be considered.
 
I think maybe we will see guidance change a little in the future to distinguish between rental properties where the landlord is responsible for safety, and a private home where the home owner is the one taking the risks.

Or maybe BS7671 should finally get round to making things a lot clearer on how to safely maintain existing installations - and remove some of the doubt.
The clarity is in EAWR (Reg 8 & 10). As for BPGs; they're 'industry' guides but as with everything you'd take it with a pinch of salt. You'll be whipped with EAWR, 7671 at a push bit I doubt the judiciary would even entertain looking at the BPGs.
 
Regarding the BPGs the IET’s Wiring Matters (May 2021) this month has this gem of a paragraph;

“The best source of information available for guidance on attributing classification codes is Electrical Safety First Best Practice Guide 4, BPG 4 is an industry-wide agreed document, contributed to by many organisations including the IET.

Ultimately it is the inspector’s engineering judgment to attribute the correct classification code, BPG 4 is a useful guide to provide a starting point for making that judgment. It is difficult to see how an inspector could deviate from this guidance without providing adequate justification.”

So, yes apply engineering judgement, but work to the BPG’s as a minimum is their take.
 
To me there is an element of judgment needed:
  • In the first case we have the current regs do not permit circuits without a CPC as it fails to meet the ADS requirements (it won't disconnect on the fault, only when someone gets a shock). So @westward10 is correct that for domestic you do not have any compliant solution, short of rewire, and if you want to avoid any issue yourself that is the simplest position to take.
  • For rental property I see that as perfectly reasonable, as the landlord is not the one open to risk of shock and to be perfectly honest, they are in it to make money so it should be compliant.
  • For home owners it is a more difficult situation. Sure you can take the above stance but if they can't rewire for whatever reason (cost probably, access or mental-health issues might also apply) doing nothing is putting them at a higher risk than, say, adding RCD protection and changing any class I fittings. Sure it is still not fully compliant so I understand why many would still say no, but you would have reduced the risk they have which is the point of the BPG#1 guidance.
But I still think plastic screws are a bit unnecessary as you are unlikely to get any life-threatening shock off something that small which you cannot grasp involuntarily. Metal plate switches, or any class I lights that are in hands-outstretched reach of sink, radiator, etc, are definitely things I would change.
 
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The coding is fairly clear - if you come across no CPC on a lighting circuit with class I fittings during an EICR, it's a C2 any day of the week.

What to do about it by way of rectifying it is the real issue.

By me swapping the lights etc to class II or otherwise double insulated fittings, I would be in contravention of reg 412.blah.blah. In other words, I would be breaking one commandment in trying to fix another commandment. Not just observing, but doing. My name is on the certification to say that is what I have chosen to do and have done. And this is what @westward10 has persistently pointed out that we should not be doing.

Food for thought.
 
Your item 5 cannot be considered in a dwelling according to BS7671. I am sure these Guides have a large brain pool behind them but nevertheless Class II should not be considered.
BPG4 is specifically titled "Classification codes for domestic and similar electrical installations"

Codes are almost by definition cases where the situation doesn't comply with BS7671. The issue is not whether it does, but whether it "requires improvement", or only is "recommended for improvement".

The issue is more whether it's acceptable to carry out remedial work that only changes the situation from C2 to C3, in order to get a "satisfactory" EICR.


It's fairly clear that putting in new circuit that would attract a C3 is not going to be compliant in pretty much every case....

Is replacing 1 light switch new work that requires complete adherence to BS7671? Or "maintenance" to leave a system safer than it was.......

I'd tend to err on the side of being OK with replacing one switch, but not every light fitting - somewhere in that range everyone needs to find their level of acceptance....
 
Finding no cpc and either situation is pretty clear - non compliance and code.
The hang up (and penny just dropped, or maybe light-bulb moment ...groan...) is normally in our day to day work we wouldn't wilfully create a C3. And that is what we'd be doing.

I won't go on like a stuck record but I am genuinely interested in one point. @Pretty Mouth I agree with number 3 as you have stated it.
I do note that both 415.1.2 which you quote and 412.1.2 have the word "sole" in them.
No argument at all from me that an RCD cannot replace any protective measure. That wasn't my point.

412.1.2 which is held up as the "you can't do this" reg (another ÂŁ5 sorry!) talks about double or reinforced insulation as the sole means of protection.
Is it any sort of argument that with an RCD the double or reinforced insulation isn't the sole means of protection as there is additional protection. If so 412.1.2 wouldn't apply. I'll get my coat....
 
Finding no cpc and either situation is pretty clear - non compliance and code.
The hang up (and penny just dropped, or maybe light-bulb moment ...groan...) is normally in our day to day work we wouldn't wilfully create a C3. And that is what we'd be doing.

I won't go on like a stuck record but I am genuinely interested in one point. @Pretty Mouth I agree with number 3 as you have stated it.
I do note that both 415.1.2 which you quote and 412.1.2 have the word "sole" in them.
No argument at all from me that an RCD cannot replace any protective measure. That wasn't my point.

412.1.2 which is held up as the "you can't do this" reg (another ÂŁ5 sorry!) talks about double or reinforced insulation as the sole means of protection.
Is it any sort of argument that with an RCD the double or reinforced insulation isn't the sole means of protection as there is additional protection. If so 412.1.2 wouldn't apply. I'll get my coat....
You cannot rely on an rcd in the absence of a cpc.
 
The clarity is in EAWR (Reg 8 & 10). As for BPGs; they're 'industry' guides but as with everything you'd take it with a pinch of salt. You'll be whipped with EAWR, 7671 at a push bit I doubt the judiciary would even entertain looking at the BPGs.
The prosecution might not raise it but you can be sure than any decent defence would use it - just as each side would have highly paid experts involved.

It would be hard for the BPG to be dismissed as irrelevant, given the status of many of the bodies behind it...

The truth is, cases will usually only get to court when something fairly egregious has occurred, such as disregarding all guidance, or falsifying records....
 
You cannot rely on an rcd in the absence of a cpc.
You're right of course.
Anyone else think the regs are a little strange sometimes?
We demand RCD's on TT systems where high earth impedance makes the earthing almost useless.
The TT'd metal consumer unit is perfectly safe even though it effectively has no earthing to speak of.
The class 1 light fitting on a TT system is deemed perfectly safe even though the only thing keeping it vaguely safe in fault conditions is really an RCD.
But for a variety of reasons the BBB says an RCD can't make a class II light fitting safe.
I guess our job is to just follow the regs and not think about them too much.
 

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