Proposal for Amendment to BS 7671 Regulation 134.1.1

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.

I see no reason to change it.

I feel sure that it says, "take account of" rather than, "follow" because of potential conflicts between BS 7671 and manufacturers' instructions.

That could be because a fixed appliance is old, but still serviceable. So what would you do if the MIs specify a 30 A fuse to protect the circuit? Does that mean that you could never install a modern DB?

Sergio Fernandez said:

as long as they are no less safe than the intent of BS 7671

That bit could be problematic, from the perspective that you would need to interpret BS 7671 to determine what it's intent is.

BS 0 advises that only a court of law can provide a definitive interpretation of a standard (meaning anything else is merely an opinion).

Hence, the form of words similar to the following is used in a number of Regulations in BS 7671: 
"at least the same degree of safety as that afforded by compliance with the Regulations"

AJJewsbury said:

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

I think this is true. Products to appropriate standards may themselves be less safe (in a particular aspect) than conformity to BS 7671, although I would point out that surely equipment ought to be selected for conformity in general.

Chris Pearson said:

I feel sure that it says, "take account of" rather than, "follow" because of potential conflicts between BS 7671 and manufacturers' instructions.

I think this is a very good point.

gkenyon said:

I think this is true. Products to appropriate standards may themselves be less safe (in a particular aspect) than conformity to BS 7671, although I would point out that surely equipment ought to be selected for conformity in general.

As an example 

If you walk into a Screwfix (other retailers/wholesalers are available) today, you might see "Type AC" RCD/RCBO still on the shelf in some clearance kits. While the product is "safe" in a lab, installing it on a circuit with modern electronics (DC leakage) is less safe than the intent of Amendment 2, which has effectively deprecated Type AC for most modern applications

Second example

13A Plug-in Shower Pumps / Waste Pumps

    The Product: Saniflo units or shower booster pumps sold with a pre-fitted 13A molded plug.  (other brands are available)

    The Conflict: The MI often says "Simply plug into a standard 13A socket."

    The "Less Safe" Gap: If that pump is installed in a bathroom (a "Special Location" under Section 7), BS 7671 generally prohibits 13A sockets within 3m of the boundary of Zone 1. An installer following the MI who plugs the unit into a socket just outside the curtain is technically following the manufacturer, but they are significantly decreasing safety compared to the BS 7671 intent of keeping current-using equipment hard-wired and protected by a 30mA RCD in those zones

With the Orange book coming, we are likely to see even more integration of "Smart" technologies and Prosumer installations. This is where the proposed wording for 134.1.1 becomes even more vital.

As software-driven devices (EV chargers, smart batteries, V2G systems) flood the market, the Manufacturer's Instructions will increasingly be "Firmware dependent." An installer following a manual printed six months ago might be installing a device that has already had its safety parameters changed by a software update.

AJJewsbury said:

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

If you applied Chapter 41 (Protection against electric shock) strictly to a toaster, it would be probably banned.  You have live/Line, glowing elements accessible to a knife (or a finger) with only "basic insulation" provided by air and a bit of toast.  It’s a manufactured appliance built to BS EN 60335. The safety "intent" is managed within the product standard, not the wiring regs.  You aren't necessarily arguing that the insides of a toaster must meet BS 7671, but that the way it is connected must.  


The BC lampholder is indeed a "legacy risk" (exposed pins when the bulb is out). However, BS 7671 acknowledges these in specific sections.  Critique suggests that if we follow the "intent" of BS 7671, we'd have to throw away all BC holders.

    The Counter-Argument is the intent of BS 7671 includes Section 511, which accepts equipment complying with an appropriate British or Harmonized standard. Therefore, if the MI says "use a BS EN 61184 lampholder," it is complying with the intent.  BS 7671 includes Section 511, which accepts equipment complying with an appropriate British or Harmonized standard. Therefore, if the MI says "use a BS EN 61184 lampholder," it is complying with the intent.

Sergio Fernandez said:

If you walk into a Screwfix (other retailers/wholesalers are available) today, you might see "Type AC" RCD/RCBO still on the shelf in some clearance kits. While the product is "safe" in a lab, installing it on a circuit with modern electronics (DC leakage) is less safe than the intent of Amendment 2, which has effectively deprecated Type AC for most modern applications

Sergio,

Not sure what you are suggesting with this? The retailer is doing nothing wrong, simply selling electrical accessories/protection devices as advertised.

Now the person that purchases the Type AC RCD/RCBO again is fully entitled to purchase those items and having Scottish Blood those items even more attractive if cost reduced in a clearance corner.

What about the Competent Designer, and Competent installer as it really falls to those persons who make the engineering safety decisions on suitability as per Regulations etc.

Other thing is, a training establishment may wish to use those items in demonstration installation set ups for training electrical technicians and inspectors, so again I see nothing wrong with the application.

Cheers GTB

Sergio Fernandez said:

The Conflict: The MI often says "Simply plug into a standard 13A socket."

Why's that a conflict? It's not saying a socket should be installed within zones of a bathroom...

   -  Andy.

Sergio Fernandez said:

  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

The wording was changed previously, (possibilty Amd. 2 of the 17th?), to the line 'take account of' whereas before it was something like 'follow MI'.

This was a good thing, as I , amongst others pointed out the ridiculous requirements by some appliance Makers, some I remember were these - item MUST be fitted by an NICEIC Electrician. Item must be protected by a 16 amp fuse. Must be wired according to BS7671 15th edition ( in the early 2000's!). The list goes on.

Manufacturers instructions can be very vague, and inappropriate, as they are not experts in electrical installations in the multiple Countries they supply, so there can be some rather stupid requirements, such as the ones above. Add in the language barrier for imported goods with translated manuals, and it is soon clear that Manufacturers Instructions should be referred to, but not necessarily complied with if they are clearly daft.

See the other thread about RCD selection. Many Manufacturers do not have a clue about what they should be recommending to be fitted to their equipment, so following the MI can lead to a worse outcome than actually following BS7671.