Is it acceptable to connect a radial to a spur via a 13A plug?

[plugwash]

True, but that's equally true whether the other end of the cable is connected to an FCU or a plug.

A FCU can't be unplugged and yanked on, a plug can.

Also flex is less good about "staying where you put it" than T&E is, and this is exacerbated by the fact that clips may be a loose fit.

However, it's not necessarily totally easy to get T+E into a BS1363 plug.

It does require some technique, at the scales of a 13A plug, a 2.5mm² solid conductor is more like a rod than a wire. My usual technique is to remove the terminals from the plug, form and terminate the conductors outside the plug, and then drop them back in.

Cheap plugs are actually easier because the pins/terminals usually just slide/fall out, while fancier plugs often have them restrained in the plug base.

Is that really true? Is there not, in fact, an argument that stranded conductors are preferable to solid ones in screwed terminals?

There is a big difference between "stranded" conductors and "fine stranded" conductors. The former are fine, the latter can be a bit unruly, finding their way up the sides of screws, or worse finding their way out of the terminal completely.

BS7671 is rather vague on this, merely talking about "suitable terminals" and "suitable preparation" but not rigidly defining what either of those things are.

 

[JohnW2]

I think we're probably quibbling about minor issues which we have agreed "are not show stoppers".

A FCU can't be unplugged and yanked on, a plug can.

If the cable is clipped to the surface of a wall/whatever, I don't think that's much more true of a plug than of an FCU, is it?

Also flex is less good about "staying where you put it" than T&E is, and this is exacerbated by the fact that clips may be a loose fit.

Again, if the cable is clipped to the surface of a wall/whatever, I think that some barrels are being scraped here, aren't they?

It does require some technique, at the scales of a 13A plug, a 2.5mm² solid conductor is more like a rod than a wire. My usual technique is to remove the terminals from the plug, form and terminate the conductors outside the plug, and then drop them back in.

Same here, but it's certainly possible (with 2.5mm² or smaller T+E).

Cheap plugs are actually easier because the pins/terminals usually just slide/fall out, while fancier plugs often have them restrained in the plug base.

Agreed.

There is a big difference between "stranded" conductors and "fine stranded" conductors. The former are fine, the latter can be a bit unruly, finding their way up the sides of screws, or worse finding their way out of the terminal completely.

I don't disagree with that, but in what way are you suggesting/implying that the terminals of an FCU differ from those of a socket?

BS7671 is rather vague on this, merely talking about "suitable terminals" and "suitable preparation" but not rigidly defining what either of those things are.

True, but probably 'understandable', given that a comprehensive definition of "suitable terminals" would probably be next-to-impossible. As you have observed, spring-loaded terminals might well be the ideal solution.

 

[plugwash]

If the cable is clipped to the surface of a wall/whatever, I don't think that's much more true of a plug than of an FCU, is it?

It's all very situationally dependent. I think it's easy to get into a situation with a short run of flex from a plug to a socket, where the clips hold the cable in place, but do not provide adequate resistance against the cable getting yanked.

Much less likely with a FCU, because you don't have the yank-prone loop of cable from the last clip to the plug.

 

[JohnW2]

It's all very situationally dependent. I think it's easy to get into a situation with a short run of flex from a plug to a socket, where the clips hold the cable in place, but do not provide adequate resistance against the cable getting yanked.

I can't disagree, but I do think that barrels are being scraped - that 'yank risk' surely exists with almost anything plugged into a socket - and, in fact, probably a much lower risk when (very unusual for 'plugged in' things) most of the cable is clipped to a wall?

Much less likely with a FCU, because you don't have the yank-prone loop of cable from the last clip to the plug.

The same 'barrel'
If the output from the FCU is a cable exiting through the faceplate and then clipped to a wall, there'll be at least a bit of a 'loop', allbeit pretty close to the wall.

 

[robinbanks]

that all begs the question

‘Tis a great shame (IMO) this interesting phrase is mutating into a paraphrase of “raises the question”..

I have had one fail with the individual socket fronts breaking free of the body. Granted I abused the thing

Hopefully you fed back to the manufacturer?! Sounds like something they should look to address with a product revision, as (if I understand your claim correctly) it’s conceivable a 3 pin plug could apply the same torque if pulled as a euro plug would, potentially causing the same fail?

I wasn’t particularly recommending that one, it was just the first reasonable brand from a reputable supplier that I found amid the wash of tosh from Amazon