downlights MR16 to GU10

[ericmark]

That seems fine to me.

 

[333rocky333]

Not to impressed personally.

Those lampholders are designed more for FIXED mounting rather than floating, hence the single insulation, no rear cable cover and no cable restraint

Though downlighter size may restrict the size you can get in

http://www.ebay.co.uk/bhp/gu10-lamp-holder

White is not a recognised colour for earth.

sorry, thats my veiw

 

[Taylortwocities]

The link that you supplied for these Aurora fittings says that they are CLASS III devices.

Explaination of the various classes can be found here
http://en.wikipedia.org/wiki/Appliance_classes

As you can see, the downlight is DESIGNED to be supplied from a separated/safety extra-low voltage (SELV) power source. The voltage from a SELV supply is low enough that under normal conditions a person can safely come into contact with it without risk of electrical shock.

By using these devices with 230V you are removing the SELV safety barrier and are converting them to an environment that they are not designed for.
If you earth the case then you are assuming they can be a Class I device, they may not be.
If you do not earth the case you are assuming that they can be a Class II device, which they clearly are not.

Without stringent testing, it is impossible to state if the case should be earthed, or not. If you want to take that risk, it is up to you. But I cannot advise you.

 

[JohnW2]

By using these devices with 230V you are removing the SELV safety barrier and are converting them to an environment that they are not designed for. ... If you earth the case then you are assuming they can be a Class I device, they may not be.

Are you thinking about the possibility of exposed/accessible live parts? If there aren't any of those, then my understanding was that any device could/would be Class I if any/all exposed-conductive-parts were earthed. Is that not correct?

Without stringent testing, it is impossible to state if the case should be earthed, or not.

Again are you perhaps talking about the possible presence of exposed/accessible live parts? If not, what tests (and what results of those tests) would indicate to you that the exposed metal parts of this fitting (which, as you've said, is clearly not Class II) should not be earthed? Since it is clearly not Class II, one thing which is surely clear is that the OP's fitting could not be used at 230V without the exposed metal parts being earthed.

The link that you supplied for these Aurora fittings says that they are CLASS III devices.

Same question, again, I suppose - are you just thinking of the possibility of exposed/accessible live parts? In the absence of that, my understanding was that Class III merely meant that, because of the SELV supply, a Class III device is not required to have the protective measures necessary for it to be either a Class II device (i.e. double insulation or equivalent) or a Class I device (i.e. earthing of all exposed-conductive-parts). Hence, my understanding was that, in the absence of exposed/accessible live parts, if one earths the exposed-c-ps of a Class III device, it becomes a Class I device. Is that wrong?

Kind Regards, John

 

[EFLImpudence]

By using these devices with 230V you are removing the SELV safety barrier and are converting them to an environment that they are not designed for. ... If you earth the case then you are assuming they can be a Class I device, they may not be.

Are you thinking about the possibility of exposed/accessible live parts? If there aren't any of those, then my understanding was that any device could/would be Class I if any/all exposed-conductive-parts were earthed. Is that not correct?

Have you got all that the right way round?

Without stringent testing, it is impossible to state if the case should be earthed, or not.

Again are you perhaps talking about the possible presence of exposed/accessible live parts? If not, what tests (and what results of those tests) would indicate to you that the exposed metal parts of this fitting (which, as you've said, is clearly not Class II) should not be earthed? Since it is clearly not Class II, one thing which is surely clear is that the OP's fitting could not be used at 230V without the exposed metal parts being earthed.

Agreed.

The link that you supplied for these Aurora fittings says that they are CLASS III devices.

Same question, again, I suppose - are you just thinking of the possibility of exposed/accessible live parts? In the absence of that, my understanding was that Class III merely meant that, because of the SELV supply, a Class III device is not required to have the protective measures necessary for it to be either a Class II device (i.e. double insulation or equivalent) or a Class I device (i.e. earthing of all exposed-conductive-parts). Hence, my understanding was that, in the absence of exposed/accessible live parts, if one earths the exposed-c-ps of a Class III device, it becomes a Class I device. Is that wrong?

I don't think you have explained/asked very well.

Surely the classifications are determined the other way round?

That is, an appliance is Class I because it requires earthing - not because it is earthed.

Similarly, a Class II appliance is so because it is double insulated and should not be earthed - not because it is not earthed.

Also, a Class III appliance is so because it is SELV and should not be earthed - not because it is not earthed.





I can see nothing wrong with what the OP has done (G/Y sleeving apart).

Changing the item form SELV to 240V with a single insulated connector would mean it is now Class I and must be earthed.

The parts are clearly the same.

The OP has done a job no worse than some manufacturers who solely rely on the contact between the bracket and the spring for their earthing of the body.

 

[Taylortwocities]

I agree. My purpose for being pedantic is that we usually hold up the MI's as THE instruction for the product. Indeed, BS7671 requires this.
This product is a Class III product.

As the OP has spotted, there is no essential difference between many ELV downlights (12v/MR16 e.g.) and the same product being presented with a mains (230v/GU10 e.g.) lamp holder.

In many cases there is no provision for an earth connection to the downlight, or for the earth conductor to be looped through the terminal box. Most only have 2 terminals, leaving the installer with a challenge on how to terminate the cpcs as they have to be connected outside the terminal box.

There is always a risk when providing 230v devices inside a metal container. That is why manufacturers determine which class the product is, and provide connections instructions that are appropriate.

Personally, I would want to see the metal case earthed in this modified product. At least the fault path will be to earth, should a supply connection chafe and make contact with the downlight's metalwork.

IMO, its up to the OP to make his own risk assessment and decide how to proceed.

 

[JohnW2]

Are you thinking about the possibility of exposed/accessible live parts? If there aren't any of those, then my understanding was that any device could/would be Class I if any/all exposed-conductive-parts were earthed. Is that not correct?

Have you got all that the right way round?

I think I have got it the right way around in my mind, but maybe that's not clear from what I wrote! What I mean is that IF a device has exposed-c-ps and IF it is not Class II or III then it is Class I IF those exposed-c-ps are (as required) earthed. My understanding is that there is not necessarily any difference (of design/construction) between a Class 0 and Class I device, the distinction really depending upon whether or not the exposed-c-ps are earthed. In other words, if one took a (probably 'not permitted') "Class 0" appliance and earthed it's exposed-c-ps, would it not become Class I (and 'permitted')?

Surely the classifications are determined the other way round? ....

Again, I probably expressed myself badly (it was late at night ) ....

That is, an appliance is Class I because it requires earthing - not because it is earthed.

Indeed - although, as above, it would seem that an identical appliance could satisfy the definition of Class 0 (and thereby almost certainly not be permitted) if it were not earthed.

Similarly, a Class II appliance is so because it is double insulated and should not be earthed - not because it is not earthed.

It's obviously true that a Class II appliance is Class II because of the double insulation (or equivalent). I'm not so sure about "should not be earthed". If there are extraneous-c-ps ('outside' of the double insulation), I don't think there is any prohibition from earthing them (not that there would be any point), is there?

Also, a Class III appliance is so because it is SELV and should not be earthed - not because it is not earthed.

Again, yes, that's obviously why it's Class III, but my comment/question about "should not be earthed" again apply. Are you suggesting that if, whilst it was still SELV, some regulations would have been violated had the exposed-c-ps been earthed?

I can see nothing wrong with what the OP has done (G/Y sleeving apart). ... The parts are clearly the same.

I agree.

The parts are clearly the same. Changing the item form SELV to 240V with a single insulated connector would mean it is now Class I and must be earthed.

Quite - at least, in order to be permitted. As above, if one changed from SELV to 230V without adding the earthing, would effectively have a (non-permitted) Class 0 device.

Kind Regards, John

 

[JohnW2]

I agree. My purpose for being pedantic is that we usually hold up the MI's as THE instruction for the product. Indeed, BS7671 requires this. This product is a Class III product.

Fair enough. Within a few months, you will hopefully be able to exercise more discretion in relation to MIs and still be compliant with BS7671.

There is always a risk when providing 230v devices inside a metal container. That is why manufacturers determine which class the product is, and provide connections instructions that are appropriate.

True, but there is a very limited number of classes to choose from. If this fitting were not used at SELV, it could not be Class III, and clearly is not Class II, and to say that it did not require an earth (Class 0) would not be permitted - so, unless you are suggesting that there are some devices/appliances/fittings which are 'classless', I can't see what it could be, when used at 230V, other than Class I (requiring exposed-c-ps to be earthed).

Personally, I would want to see the metal case earthed in this modified product. At least the fault path will be to earth, should a supply connection chafe and make contact with the downlight's metalwork.

I would say that it's much stronger than just your personal view. By effectively converting the fitting into a Class I one, the OP will have surely made it (in anyone's eyes) essential that the exposed-c-ps be earthed, won't he?

IMO, its up to the OP to make his own risk assessment and decide how to proceed.

Indeed, and it sounds as if he has done that - and, IMO, in a not unreasonable way.

Kind Regards, John

 

[EFLImpudence]

What I mean is that IF a device has exposed-c-ps and IF it is not Class II or III then it is Class I IF those exposed-c-ps are (as required) earthed.

No, that is my point; the classification depends on the design and what is required.
IF you earth the metal parts (e-c-ps?) of Class II or III appliances it does not become Class I; it becomes a more hazardous, wrongly earthed Class II or III appliance.

My understanding is that there is not necessarily any difference (of design/construction) between a Class 0 and Class I device, the distinction really depending upon whether or not the exposed-c-ps are earthed.

There may be no difference in the construction of the housing of 0, I, II, or III items; the difference is in the construction of the electrical parts and hence the requirements.

In other words, if one took a (probably 'not permitted') "Class 0" appliance and earthed it's exposed-c-ps, would it not become Class I (and 'permitted')?

I suppose that is true because Class 0 is just Class I without the earth (I think).
As it's not allowed in domestic premises it is irrelevant.

Similarly, a Class II appliance is so because it is double insulated and should not be earthed - not because it is not earthed.

It's obviously true that a Class II appliance is Class II because of the double insulation (or equivalent). I'm not so sure about "should not be earthed". If there are extraneous-c-ps ('outside' of the double insulation), I don't think there is any prohibition from earthing them (not that there would be any point), is there?

What do you mean by 'outside' of the double insulation?
There are metal Class II fittings which must not be earthed for safety reasons but if for no other reason than the MIs.

Also, a Class III appliance is so because it is SELV and should not be earthed - not because it is not earthed.

Again, yes, that's obviously why it's Class III, but my comment/question about "should not be earthed" again apply. Are you suggesting that if, whilst it was still SELV, some regulations would have been violated had the exposed-c-ps been earthed?

I am not sure if a regulation would have been violated as they do not normally state 'don't do something which is not necessary'.
However, earthing isolated parts is not a good idea.

 

[JohnW2]

What I mean is that IF a device has exposed-c-ps and IF it is not Class II or III then it is Class I IF those exposed-c-ps are (as required) earthed.

No, that is my point; the classification depends on the design and what is required.

My understanding is that there is not necessarily any difference (of design/construction) between a Class 0 and Class I device, the distinction really depending upon whether or not the exposed-c-ps are earthed.

There may be no difference in the construction of the housing of 0, I, II, or III items; the difference is in the construction of the electrical parts and hence the requirements.

I was talking about all aspectsof construction, including that of the 'electrical parts'.

In other words, if one took a (probably 'not permitted') "Class 0" appliance and earthed it's exposed-c-ps, would it not become Class I (and 'permitted')?

I suppose that is true because Class 0 is just Class I without the earth (I think).

Exactly. If I'm not mistaken, you have talked yourself around to agreeing with my very point [and, conversely, Class I is just Class 0 with earthing connected to the exposed parts - Class 0I {or is it oI?} sort-of recognises that].

There are metal Class II fittings which must not be earthed for safety reasons but if for no other reason than the MIs.

I don't totally follow - do you mean 'for safety reasons' or 'because of the MIs'? - which aren't necessarily the same thing! Apart from the fact that it is theoretically undesirable to 'unnecessarily earth' anything (be it a metal Class II appliance, a bath, doorknob or spoon!), are you aware of any specific safety issues associated with earthing exposed metal parts of a Class II device/appliance?

I am not sure if a regulation would have been violated as they do not normally state 'don't do something which is not necessary'. However, earthing isolated parts is not a good idea.

See above.

Kind Regards, John