Class I or class II appliance?

[baldsparkies]

Happy with the class 2 insulation of the motor, but what level of protection is afforded to the supply caple as it enters the conductive part ie casing ??
Now this guy has brought it to your attention, jobs worth or not, for the sake of supplying an earth I would go for it. NOT the motor though just the casing.

 

[davelerave]

i see your point now NovusSparkus

the casing is separate to the class2 motor

still reckon it won't need earthing if it's installed properly

 

[Adam W]

How do you ascertain whether or not it's been installed 'properly'?
If you earth it you can just do an earth bond test.

 

[Deleted member 9648]

How do you ascertain whether or not it's been installed 'properly'?
If you earth it you can just do an earth bond test.

Personally I think you ascertain whether or not the case needs to be earthed by having a look......as the only supposedly competent person to have seen it is the alleged jobsworth I think you are all jumping the gun becoming entrenched in the earth or not earth camps.

 

[pushrod]

Not sure if it has been said or not (just skimmed most of it), but i would have thought design engineer's instructions would take precedence assuming it meets a BS standard?

 

[Engineer54]

Sounds pretty weired to me, earthing a purpose made metallic tubular enclosure to a BS rated double insulated motor!!!

 

[telectrix]

back to the days of the 15th... if it's metal and it don't move, earth it.

 

[paturback]

If this is the sort of motorised blind the op is referring to which is the only type I've seen then imho introducing an earth potential to the "metal cassette" is certainly questionable as the cable does not enter the cassette.

Definitions
Class 2 equipment
Protection against electric shock does not rely on basic insulation only,additional safety precautions included and no provision for connection of exposed metal work of the equipment to a circuit protective conductor

Exposed conductive part (Which it appears your metal cassette is being classed as )
Exposed conductive part of equipment is equipment that can be touched and which is normally live when basic insulation fails

If basic insulation fails there would not be live metal contact,because of the presence of supplementary insulation

My veiw is the cassette is not an exposed conductive part and the class 2 insulation protective measure seems to be adequate
Because that metal enclosure forms the containment,it has not become an exposed conductive part

I'm with Des's 1st response

 

[nikmet]

Could the motor and wiring not be removed?, this could then be replaced by a loop of cord to manually lift the blind up and down............problem solved :-D

 

[SirKit Breaker]

Does it have the square box within another square box symbol on it anywhere? If it does it is class 2. For the purposes of In Service test and Inspection of Electrical Equipment (you may know it as PAT testing) if you cannot ascertain whether the piece of kit is a Class 1 or Class 2 appliance, then it must be assumed to be Class 1, and tested accordingly.

Cheers..Howard

 

[Elidor]

Not 100% how it’s all assembled but would the enclosure and the rest of the installation be classed as an extraneous conductive part?

 

[Carter]

Seems to me this is more a matter of good installation practice. I've lost count of the number of scenarios where I've had to bring flexes in and out of containment, machinery and enclosures. With correct grommeting, glanding, well thought out cable support, routing and properly fixed cable restraint there is no issue. You've not created a new product or machine here and all your fixings will be CE app'd and fit for the intended conditions of use.
If however the intention is to run loose i.e. unrestrained flexes across metal edges and surfaces then THAT'S when an alarm would start to ring in my mind and your maintenance dude would have a fair point. It is a moving system after all and therefore subject to vibration, wind movement, wear, abrasions and of course Sod's Law!

All is conjecture without a few piccys.

 

[Des 56]

Seems to me this is more a matter of good installation practice. I've lost count of the number of scenarios where I've had to bring flexes in and out of containment, machinery and enclosures. With correct grommeting, glanding, well thought out cable support, routing and properly fixed cable restraint there is no issue. You've not created a new product or machine here and all your fixings will be CE app'd and fit for the intended conditions of use.
If however the intention is to run loose i.e. unrestrained flexes across metal edges and surfaces then THAT'S when an alarm would start to ring in my mind and your maintenance dude would have a fair point. It is a moving system after all and therefore subject to vibration, wind movement, wear, abrasions and of course Sod's Law!

All is conjecture without a few piccys.

Quote
Part of the original topic question

but if adequate measures of protection have been taken to prevent this potential issue is it still necessary to earth the cassette mechanism

regards Des

 

[Carter]

Quote
Part of the original topic question

but if adequate measures of protection have been taken to prevent this potential issue is it still necessary to earth the cassette mechanism

regards Des

Much obliged Des but as a layman his definition of adequate might not match yours and mine. A pic would certainly clarify things and enable a proper diagnosis.

 

[Engineer54]

These tubes/cassettes are purpose made to house these Class 2 blind motors, ....Sooooooo why would they need to be earthed????