Connecting a LED security light.

[EFLImpudence]

I would say that I think you may be looking at things from the wrong perspective.

I have no official confirmation but I think it probable that the requirements of Class II specification are not to prevent us getting at live parts but rather to prevent live parts getting at us.

 

[JohnW2]

I would say that I think you may be looking at things from the wrong perspective. I have no official confirmation but I think it probable that the requirements of Class II specification are not to prevent us getting at live parts but rather to prevent live parts getting at us.

Is that not a purely academic/semantic distinction?

Particularly given that it is all in the chapter of BS7671 entitled "Protection against Electric Shock", the purpose of "Class II" is surely to prevent people being able to come into contact with live parts - who/what is "getting at" who/what is surely irrelevant? In my photo, if that little plastic cover were to break up or fall off, one would be faced with potentially touchable live parts - conceptually (albeit not as seriously) the same as a CU with it's front cover 'fallen off' and an unprotected L busbar exposed.

Kind Regards, John

 

[EFLImpudence]

Is that not a purely academic/semantic distinction?

I don't think so.
Your argument about the OP's light is that if you undo four screws and remove the lid, you can then pick up a nail and touch a live screw with it.
Whereas, when assembled and in use it is nigh on impossible for anything to happen which would cause you to get a shock.

Particularly given that it is all in the chapter of BS7671 entitled "Protection against Electric Shock",

Does it say anywhere "Don't lick a live conductor"?

the purpose of "Class II" is surely to prevent people being able to come into contact with live parts

Precisely, there is nothing which can be done to prevent people taking it to pieces and then coming into contact.

In my photo, if that little plastic cover were to break up or fall off, one would be faced with potentially touchable live parts - conceptually (albeit not as seriously) the same as a CU with it's front cover 'fallen off' and an unprotected L busbar exposed.

I agree that it looks a bit unsubstantial but it must be adequate.

The CU is a good example - even though not officially Class II ???
You are not going to get a shock unless you take off the cover.
The cover will not fall off unless someone has damaged it.

 

[JohnW2]

Your argument about the OP's light is that if you undo four screws and remove the lid, you can then pick up a nail and touch a live screw with it.

Not at all - I've never produced such an argument. As far as I am concerned, Class II (or whatever) is nothing to do with deliberately opening enclosures. Rather, it's about the possibility of the protective layer 'breaking' in some way and exposing potentially live parts beneath. Class II seems to allow one to address that in two ways - either to have 'double insulation', such that breakage of one layer will not expose any live parts or, alternatively, to make the single barrier sufficiently robust ('reinforced') that it is very unlikely to break.

However, none of this goes any way to answering the question I posed in the furtherance of my education - namely if it can't be Class I (no metal) is there anything else it is 'allowed' to be other than Class II - and, if so, what?

Kind Regards, John

 

[EFLImpudence]

Class II seems to allow one to address that in two ways - either to have 'double insulation', such that breakage of one layer will not expose any live parts or,

Ok. I am saying the connector block is the first insulation and the containing box is the second

OR

The containing box is reinforced (whatever that means in context).

However, none of this goes any way to answering the question I posed in the furtherance of my education - namely if it can't be Class I (no metal) is there anything else it is 'allowed' to be other than Class II - and, if so, what?

I've said I don't know - and nor, it seems, does anyone else.

 

[JohnW2]

Ok. I am saying the connector block is the first insulation and the containing box is the second ... OR ... The containing box is reinforced (whatever that means in context).

Quite - and, as I said, unless someone can tell me of any other possibilities, I suppose that I have to assume that if neither of those is deemed to be the vase, then is is "not allowed"

I've said I don't know - and nor, it seems, does anyone else.

Fair enough. As I've said, I'm not arguing about anything but, rather, am trying to learn - about something I've never fully understood. However, as you imply, it looks as if I'll have to give up, since no-one appears to be able to 'teach' me

Kind Regards, John