The most basic problem with DIY work

[JohnW2]

It seems quite clear - to me at least - that table 2 fuse ratings are a complete balls up using the 3A and 13A fuse preferences as a baseline to work from.

I think the fuse ratings specified in Table 2 are fine in the context of the primary purpose of that Table - i.e. to specify the test conditions for the flexing and cord grip tests, which use a test current greater than the CCC of the cable.

As BAS has identified, the problem is that they have also referred to Table 2 in the context of specifying the required marking of non-rewirable plugs. However, as you will have seen, BAS and I have different views about the interpretation of what that is saying.

Kind Regards, John

 

[JohnW2]

I personally don't think I agree that BS1363 is saying that one can 'fit' a fuse which is higher in rating than the the CCC of the cable, if that is the justification they're trying to use.

It has occurred to me that it might conceivably just be a 'typo' (ill-considered wording). It certainly seems odd (at least to me) that they should refer back to the fuse ratings specified as test conditions for a test employing currents >CCC. Do you think it conceivable that, rather than "... which shall not exceed the value given in Table 2 for the appropriate size of flexible cord", they actually intended to write something like "... which shall not exceed the rated current given in Table 2 for the appropriate size of flexible cord"? - which would make total sense.

Kind Regards, John

 

[ban-all-sheds]

Possibly, but then the problem is that all fuse ratings apart from 3 and 13 are deprecated bs BS 1363, so as soon as the "rated current" goes over 3A you have to go to 13.

 

[JohnW2]

Possibly, but then the problem is that all fuse ratings apart from 3 and 13 are deprecated bs BS 1363, so as soon as the "rated current" goes over 3A you have to go to 13.

What form does this 'deprecation' take? .. and do you see any sense in it?

Kind Regards, John

 

[ban-all-sheds]

" NOTE For rewireable accessories the preferred ratings of
fuse-links are3 A and 13 A.
For non-rewireable accessories the current rating of
the fuse-link shall be appropriate to the attached
flexible cord (see Table 2). ".

And no.

 

[JohnW2]

" NOTE For rewireable accessories the preferred ratings of fuse-links are3 A and 13 A.

Hmmm - what on earth does 'preferred' mean and, as we are both effectively asking, why on earth do they have such a (seemingly illogical and potentially even dangerous) 'preference'!

"For non-rewireable accessories the current rating of the fuse-link shall be appropriate to the attached flexible cord (see Table 2). ".

... which, to my mind, is again ambiguous. Do they mean 'appropriate to the attached flexible cord' in relation to the fuse rating (for the particular tests) specified in Table 2, or in relation to the 'rated current' specified in Table 2?

Kind Regards, John

 

[ban-all-sheds]

I believe that they mean the fuse rating to cable relationship detailed in Table 2, so 3A or 13A.

As to why? IHNI.

I've got 1, 3, 5, 7, 10 & 13A fuses in stock (TBH I don't know why), but I can't see how BS 1363 "preferring" 3, 7 and 13A would be unworkable, with simple instructions for Joe P:

Up to 500W

500 - 1500

over 1500

 

[JohnW2]

I believe that they mean the fuse rating to cable relationship detailed in Table 2, so 3A or 13A.

You might be right - but, as I said, I think it's ambiguous.

As to why? IHNI.

Quite so!

I've got 1, 3, 5, 7, 10 & 13A fuses in stock (TBH I don't know why)...

Similar here, but I also have some 2A, but don't have 7A (didn't even know that they existed).

... but I can't see how BS 1363 "preferring" 3, 7 and 13A would be unworkable, with simple instructions for Joe P:....

Sure, if one's only concern is cable protection, that would be OK (as would a 3A, 6A and 13A, if a 6A existed) ... it's the big gap between 3A and 13A which is the problem.

Kind Regards, John

 

[securespark]

Into hot water with whom? Did you argue your case?

Yes.

I got into trouble because the householder had a brand new fridge freezer: just unwrapped that morning. He was not expecting it to fail a PAT test!

I explained my position from the perspective of BS7671. He spoke to the manufacturers and their tech. dept. explained their position from their perspective.

 

[plugwash]

And also that table has a footnote allowing a 5A fuse with 0.5mm flex under certain conditions. Why would they put that in if it's intended use was only to specify what should be in the plug during a test.

 

[JohnW2]

Into hot water with whom? Did you argue your case?

Yes. I got into trouble because the householder had a brand new fridge freezer: just unwrapped that morning. He was not expecting it to fail a PAT test! I explained my position from the perspective of BS7671. He spoke to the manufacturers and their tech. dept. explained their position from their perspective.

I see! As a matter of interest, what was the manufacturers' perspective - was it they who cited BS1363 as their 'excuse'?

I wonder what the underlying issue is. Do you think the manufacturer's feel that a 13A fuse is actually required in order to cope with the inrush current of the compressor, or are they just blindly following some 'rules' (such as BS1363)? Do the MIs require a 13A fuse? If not, did you consider offering to change it to a 5A one and the passing the item?

I'm a bit uncertain as to the scope of various regulations and as to exactly what regulations/rules/whatever apply to PATesting. Does BS7671 not apply to such appliances as this? If it did, the situation you were faced with was clearly non-compliant with BS7671 (unless you would be comfortable in saying that a fridge-freezer cannot create an overload {but I wonder what current the compressor motor would draw if it jammed?}), hence difficult to see how/why it should pass a PATest.

This whole situation seems to be an awful mess!

Kind Regards, John

 

[JohnW2]

And also that table has a footnote allowing a 5A fuse with 0.5mm flex under certain conditions. Why would they put that in if it's intended use was only to specify what should be in the plug during a test.

Indeed - I wondered the same thing. It seems that much of this mess (at least, our uncertainties/discussions about what it's all meant to mean) stems from the fact that they've been lazy and have tried to use one Table to serve at least two (perhaps three) entirely different purposes!

Kind Regards, John

 

[JohnW2]

...Why would they put that in if it's intended use was only to specify what should be in the plug during a test.

I forgot to add ... if they really wanted to use this Table for multiple purposes, they certainly should have at least used a different title from what they did - which refers only to the tests!

Kind Regards, John

 

[ban-all-sheds]

Does BS7671 not apply to such appliances as this?

110.1.2(iii) and 113.1 would indicate not.

 

[JohnW2]

Does BS7671 not apply to such appliances as this?

110.1.2(iii) and 113.1 would indicate not.

OK - but per 110.1.2(iii), BS7671 does not apply only if the 'wiring system and cable' of the appliance is covered by "the standards for appliances". It therefore seems that we need to know what the "standards for appliances" (which are they?) have to say about this. If they have specific requirements for protection of the mains cable, then we'll have an answer. If there are no such specific requirements, then it would look as if BS7671 would apply.

Kind Regards, John