Is there a either class I or II class.

[ericmark]

With extra low voltage we have three classes the SELV must not be earthed, the PELV must be earthed and the FELV can be either earthed or not earthed.

However with low voltage we have Class I must be earthed, and Class II which does not normally have an earth. The question is are you allowed to earth Class II equipment?

It was a rota broach where I had to make that decision am I allowed to earth Class II equipment, the unit was held in place with an electro magnet which was Class I but the hole was drilled with a modified standard drill which was Class II with the markings plainly visible. However since the two units were bolted together as one tool both devices would be earthed if one was earthed.

So two scenarios, either the whole unit is condemned or an earth is used. I fitted an earth but in hind sight not sure this was the correct option. Earthing a Class II device could cause danger or it may not matter, why is there not the P and F versions of Class II?

 

[EFLImpudence]

With extra low voltage we have three classes the SELV must not be earthed, the PELV must be earthed and the FELV can be either earthed or not earthed.

However with low voltage we have Class I must be earthed, and Class II which does not normally have an earth.

You can have separated low voltage.

The question is are you allowed to earth Class II equipment?

Not according to the MIs.

It was a rota broach where I had to make that decision am I allowed to earth Class II equipment, the unit was held in place with an electro magnet which was Class I but the hole was drilled with a modified standard drill which was Class II with the markings plainly visible. However since the two units were bolted together as one tool both devices would be earthed if one was earthed.

So two scenarios, either the whole unit is condemned or an earth is used. I fitted an earth but in hind sight not sure this was the correct option. Earthing a Class II device could cause danger or it may not matter,

You have to earth the Class I part so yes it has to be earthed.

why is there not the P and F versions of Class II?

Not necessary?

 

[JohnW2]

The question is are you allowed to earth Class II equipment?

Not according to the MIs.

As I have just asked you in another thread, what is it that 'must not be earthed'? If a Class II item happens to have an outer 'exposed part which is made of conductive material' (not an 'exposed-conductive-part', by BS7671 definition, which Class II items don't have) what harm can possibly come from earthing it (other than the general undesirability of 'unnecessarily earthing' anything)??

Kind Regards, John

 

[EFLImpudence]

I refer the honourable gentleman to my reply in the other thread.

Although, perhaps it would be more productive if I wrote it twice.

 

[bernardgreen]

However since the two units were bolted together as one tool both devices would be earthed if one was earthed.

Only one is earthed, the other is bonded to it ....... simples.