Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • Replies 2 replies
  • Subscribers 37 subscribers
  • Views 34 views
  • Users 0 members are here
Options
You may also be interested in

Proposal for Amendment to BS 7671 Regulation 134.1.1

Sergio Fernandez

Regulation to be Amended

134.1.1 (Good workmanship and manufacturer's instructions)
Proposed New Wording

    Good workmanship by one or more skilled or instructed persons and proper materials shall be used in the erection of the electrical installation. The installation of electrical equipment shall take account of relevant manufacturers' instructions as long as they are no less safe than the intent of BS 7671.


Statement of Problem/Reason for Change

    Ambiguity of "Take Account of": The current wording is often interpreted as an absolute requirement to follow Manufacturer’s Instructions (MI), even when those instructions are generic, poorly translated, or based on non-UK earthing arrangements (e.g., ignoring PME risks).

    Safety Hierarchy: Currently, installers face a conflict when an MI contradicts a fundamental safety principle of BS 7671. This proposed wording clarifies that BS 7671 remains the primary safety framework for UK installations.

    Accountability of the Skilled Person: It empowers the "Skilled Person" to exercise professional judgment. If an MI suggests a method that provides a lower level of safety (e.g., regarding RCD selection or earthing), the installer is explicitly authorized to prioritize the higher standard.

Supporting Examples for the "Safety Case"

    EVSE Installations: Where MIs might suggest a lack of RCD protection that contradicts Section 722.

    Terminations: Where MIs for domestic accessories may not account for the thermal effects of high-load continuous use (e.g., EV or Heat Pump circuits).

    Foreign Equipment: Industrial machinery with MIs written for IT or TT systems being installed on a UK TN-C-S system.

As always please be polite and respectful in this purely academic debate.





Come on everybody let’s help inspire the future

  • I agree with the concept, and probably interpret the current clause as  if that is more or less what it meant. However it assumes that folk will all agree about the intent of BS7671 - and there are a great many discussions here and in other places that suggest there will be quite a few corner cases where they may not.   

    I think that one problem of poor instructions is that they tend to accompany the cheapest product, and get installed perhaps by the cheapest bidder, who may not always be best placed to make that judgement - look at the no. of folk using tick sheets to do EICRs who cannot really say why the thing they have flagged is that code, beyond, 'its in the book' , 

    So even if the wording was changed, I think we'd still see a fair few oddities.

    Don't assume that all the UK is TNC-s by the way, or for that matter that BSS7671 is the last word in safety, more of a minimum in some areas. Here - a modest market town in Hampshire, there are town centre streets of houses and shops fed by overhead TT and mural wiring that is just post war. (though the 1970s flats are indeed PME, the transformer is in the basement )

    This makes decisions about supplies to sheds, hot tubs and car chargers very easy, but leaves a nervous feeling with metal consumer units that have pre-RCD wiring within them, especially when they are out of town and getting a bit rusty in barns and so on.

    Mike. 

  • While I share you perception that a lot of MI don't make a lot of sense, I'm not sure about applying installation standards (e.g. BS 7671) flatly to the detail of individual items of equipment - sometimes the principles are fundamentally different either for physical or historical reasons - e.g. you couldn't you install a traditional BC lampholder or domestic toaster if you had to directly apply the safety principles contained within BS 7671.

      - Andy.

Community Rules & Guidelines