Basic insulation exposed in electrical outdoor meter box.

Does BS 7671 explicitly carry EN 60721 external-influence concepts into Appendix 5? So that utilisation by ordinary persons (BA1) is itself an external influence that must be applied with 416.2.3 to meter cabinets opened by householders in normal service?

Hi S. I’ve given this topic much thought. Yes, BA1 (ordinary, uninstructed persons such as householders) is a utilisation-related external influence. But, Regs 416.2.1 and 416.2.3 focus on preventing access to live parts, not basic insulation

I mentioned earlier in this debate about potential non-compliance with Reg 521.10.1, 526.8 In a meter cabinet opened by BA1 persons, with exposed basic insulation is vulnerable to accidental damage or degradation, potentially leading to live parts becoming exposed over time. While the cabinet may meet IP2X requirements when closed, does it fully address the risks during normal service when householders access it. I think it’s a case of prioritising expediency over safety with the SWA cores exposed install method. I don’t think it can be argued against as it seems to meet 7671 standard.

Hello,

Thankyou for the detailed reply.

As a total non expert who has only seen this on social media, that clarified the source of contention which I couldn't wrap my head around. I can now see how that could be argued as actually maintaining protection.

AMK said:

I mentioned earlier in this debate about potential non-compliance with Reg 521.10.1, 526.8

As I think we have already established, the answer hinges on whether a meter cabinet is an enclosure or not.

Just as a matter of interest, how would people feel about "singles" just sitting there in the meter cabinet? (Obviously excluding G/Y.)

S said:

So that utilisation by ordinary persons (BA1) is itself an external influence

Well, ordinary persons fit the definition. They also include children, who are both at a convenient height for peering into a mater cabinet, and curious.

as mentioned previously ... page 20 and page 24 of this document  offers an opinion, re: 'supply'  ...  does it help in relation to the OP title or question

www.electricalsafetyfirst.org.uk/.../best_practice-guide-4_issue-7-2.pdf

Thanks for the link psychicwarrior. Page 20 seems to refer to situations when connecting to an accessory giving it a C2, so not relevant to this discussion. Page 24, singles in a meter cupboard is just an observation? Really it shouldn’t be an observation as it complies with BS7671. You wouldn’t put down singles in an enclosure as an observation anywhere else. 

Page 20 does seem relevant - perhaps you did not see the section on a C2 for 'supply'  ?    (as it perhaps displays differently on your reader)

The article details OBS as:

"Observations (obs)
Items worthy of note, that are not non-
compliances with BS 7671, but which
do not warrant a classification code."

It seems the 'best practice guide' authors consider what's in meter cabinets as something to inspect and further,  that a C2 or an OBS  depending on criteria could be applicable.    Is it in reference to what might be the customers gear only, or including supplier gear too, is not detailed.

Thanks again. So, the meter cabinet is classified as an enclosure, and, like any enclosure, it should be inspected. Any non-compliances should be coded appropriately based on their severity. I understand this. Since it’s established that a meter cabinet is an enclosure, the use of basic insulation for exposed SWA cables is a satisfactory installation method, and nothing in BS7671 indicates otherwise. I suppose that’s that then. 

To be honest, I despair at those who wish to rush us to undertake even more responsiblilities which should lie with others.

The meter enclosure belongs to the DNO, so why should we have to undertake responsibilty for the inspection of something which is in reality, nothing to do with us?

The meter enclosure belongs to the customer.  The kit inside it belongs to the DNO.