Class I or Class II ?

[JohnW2]

"Provision for earthing" what? If it is a totally insulated item, then (given that these 'Classes' are all about protecting 'outsiders' from risk of electric shock) it would seem pretty irrelevant as to whether or not anything from which an outsider was adequately insulated (i.e. to Class II standards) was 'earthed' or not. This is all very confusing!

Hence my comment about no further elaboration on the type of earthing. Their outlook seems to be if there's an earth going in, it's Class I.

That's really just changing the words - "an earth going in" is not really any clearer than "provision for earthing". Given the general requirement for fixed wiring cables to have CPCs, many Class II items have provision for terminating the (unused) CPC in a terminal which is connected to nothing. Does that count as "provision for earthing" or "an earth going in"?

Kind Regards, John.

 

[Grizzly]

That's really just changing the words - "an earth going in" is not really any clearer than "provision for earthing". Given the general requirement for fixed wiring cables to have CPCs, many Class II items have provision for terminating the (unused) CPC in a terminal which is connected to nothing. Does that count as "provision for earthing" or "an earth going in"?

Kind Regards, John.

Well, we're back to that grey area again.
The IEE CoP is really only relevant to appliances, not fixed wiring accessories.
So our laptop charger seems to be more clear cut than say a ceiling rose that has an earth terminal that doesn't actually earth anything.

We'll probably never arrive at an all-encompassing answer.

 

[JohnW2]

That's really just changing the words - "an earth going in" is not really any clearer than "provision for earthing". Given the general requirement for fixed wiring cables to have CPCs, many Class II items have provision for terminating the (unused) CPC in a terminal which is connected to nothing. Does that count as "provision for earthing" or "an earth going in"?

Well, we're back to that grey area again.

We are, indeed - and hence again back to the reason I started this discussion/thread.

The IEE CoP is really only relevant to appliances, not fixed wiring accessories. So our laptop charger seems to be more clear cut than say a ceiling rose that has an earth terminal that doesn't actually earth anything.

That may be the case, but from the point of view of electricians (as opposed, I guess, to 'PAT testers'), the main interest is in fixed appliances (not only 'accessories') rather than 'plugged-in appliances' - e.g. things like ELV lighting 'transformers', other lighting fittings, extractor fans, shower units etc. etc.

We'll probably never arrive at an all-encompassing answer.

That was, and remains, my suspicion/fear !

Kind Regards, John.

 

[Grizzly]

That may be the case, but from the point of view of electricians (as opposed, I guess, to 'PAT testers'), the main interest is in fixed appliances (not only 'accessories') rather than 'plugged-in appliances' - e.g. things like ELV lighting 'transformers', other lighting fittings, extractor fans, shower units etc. etc.

Fixed appliances should be treated the same as plugged-in appliances for the purposes we've been discussing (if one is an electrician or 'PAT' tester, or maybe some of both).

It's fixed wiring accessories where the problem seems to lie.

 

[JohnW2]

Fixed appliances should be treated the same as plugged-in appliances for the purposes we've been discussing (if one is an electrician or 'PAT' tester, or maybe some of both).
It's fixed wiring accessories where the problem seems to lie.

Is it? I just gave a few quick examples of what I would regard as 'fixed appliances', rather than 'wiring accessories'.

Virtually by definition, a 'fixed appliance' will have a CPC 'entering it' (since fixed wiring cables have CPCs) and some of what you've recently written would suggest that this makes them Class I - yet many/most of the things I'm thinking of are (I would say, very reasonably) regarded, and marked, as Class II.

Kind Regards, John.

 

[Grizzly]

Virtually by definition, a 'fixed appliance' will have a CPC 'entering it' (since fixed wiring cables have CPCs) and some of what you've recently written would suggest that this makes them Class I - yet many/most of the things I'm thinking of are (I would say, very reasonably) regarded, and marked, as Class II.

Well no.
A lot of Class II fixed appliances might be connected via a 2-core cable to a junction box/FCU etc, so wouldn't have the CPC entering them.
And I think we also need to make a distinction between if an earth terminal is provided inside a Class II appliance (specifically as opposed to an accessory) to if the installer has decided to bung the cpc inside when wiring it up.
I would be interested to hear of any declared and marked Class II appliances that had such a thing.

 

[JohnW2]

Virtually by definition, a 'fixed appliance' will have a CPC 'entering it' (since fixed wiring cables have CPCs) and some of what you've recently written would suggest that this makes them Class I - yet many/most of the things I'm thinking of are (I would say, very reasonably) regarded, and marked, as Class II.

Well no. A lot of Class II fixed appliances might be connected via a 2-core cable to a junction box/FCU etc, so wouldn't have the CPC entering them.

Some will be, yes - but, equally, some will be wired with T&E - and unless something 'unacceptable' is done to the cable, the CPC is bound to enter the appliance.

And I think we also need to make a distinction between if an earth terminal is provided inside a Class II appliance (specifically as opposed to an accessory) to if the installer has decided to bung the cpc inside when wiring it up. I would be interested to hear of any declared and marked Class II appliances that had such a thing.

I'm sure that I've seen plenty of Class II appliances which include a terminal for terminating a CPC. I'll see if I can find some for you - watch this space!

Kind Regards, John.

 

[Grizzly]

Some will be, yes - but, equally, some will be wired with T&E - and unless something 'unacceptable' is done to the cable, the CPC is bound to enter the appliance.

But that's not the same as a provision being made for earthing.
By 'earth going in', I would have thought it quite obvious that it is going in for a purpose.
A Class II appliance wouldn't have that provision.

I'm sure that I've seen plenty of Class II appliances which include a terminal for terminating a CPC. I'll see if I can find some for you - watch this space!

With baited breath!

 

[EFLImpudence]

Again, from the IEE CoP:

Chapter 11.2, page 56
"Class II equipment may be insulation-encased or metal-encased.

Insulation-encased Class II. Equipment having a durable and substantially continuous electrical enclosure of insulating material that envelopes all conductive parts with the exception of small parts such as name plates, drill chucks, screws and rivets, which are insulated from live parts by insulation at least equivalent to reinforced insulation. The enclosure of an insulation-encased Class II appliance may for part or the whole of the supplementary insulation or reinforced insulation.

Metal-encased Class II. Class II equipment may have a substantially continuous metal enclosure with double or reinforced insulation used throughout."

Well, I do stand corrected. I was only looking at the definitions in 7671.

Another case of the regulations written less carefully than they may be ?

 

[JohnW2]

I'm sure that I've seen plenty of Class II appliances which include a terminal for terminating a CPC. I'll see if I can find some for you - watch this space!

With baited breath!

Do you accept this as an 'appliance', rather than 'accessory'?

Untitled

• JohnW2
• 4 Aug 2012
• 1

I must say that I'm a little surprised that the flimsy bit of transparent plastic (hardly 'reinforced' to my mind!) protecting the 230V input terminals qualifies for Class II status - but, in any event, the point is that a terminal for terminating the CPC of the incoming cable is there. I'll see if I can find some better examples.

Kind Regards, John.

 

[Grizzly]

I'm sure that I've seen plenty of Class II appliances which include a terminal for terminating a CPC. I'll see if I can find some for you - watch this space!

With baited breath!

Do you accept this as an 'appliance', rather than 'accessory'?

Untitled

• JohnW2
• 4 Aug 2012
• 1

I must say that I'm a little surprised that the flimsy bit of transparent plastic (hardly 'reinforced' to my mind!) protecting the 230V input terminals qualifies for Class II status - but, in any event, the point is that a terminal for terminating the CPC of the incoming cable is there. I'll see if I can find some better examples.

Kind Regards, John.

I would debate as to if that qualifies as 'provision for earthing'.
Nothing is being earthed.

 

[JohnW2]

I would debate as to if that qualifies as 'provision for earthing'. Nothing is being earthed.

I've never said that it was. I have repeatedly stated that I was talking about a terminal (connected to nothing) provided for termination of a CPC - and it was in relation to that that you challenged me to provide an example.

Is it just me, or are there some mobile goalposts floating around this discussion?

Kind Regards, John.

 

[EFLImpudence]

So, what is it about that device that provides the Class II requirements.

The terminals are not double-insulated nor does the cover look reinforced.

In fact, it looks no better than the accessories which lead to the original query.

 

[Grizzly]

I would debate as to if that qualifies as 'provision for earthing'. Nothing is being earthed.

I've never said that it was. I have repeatedly stated that I was talking about a terminal (connected to nothing) provided for termination of a CPC - and it was in relation to that that you challenged me to provide an example.

Is it just me, or are there some mobile goalposts floating around this discussion?

Kind Regards, John.

Some opinions may have been revised...

 

[Grizzly]

So, what is it about that device that provides the Class II requirements.

The terminals are not double-insulated nor does the cover look reinforced.

In fact, it looks no better than the accessories which lead to the original query.

As we don't seem to have access to the standard (BS 2754) that specifies exactly how an appliance might meet the requirements, any criticism of it's construction is not much better than guesswork, really.
The manufacturer (Aurora) have stated that they have constructed it to meet the requirements of the standard (by using the Class II mark), and unless we believe it is a fraudulent claim, we should take their word for it.
If you do believe it is a fraudulent claim, it should be pursued with Trading Standards.