Non-Conducting Location.

Zoom, is it to be a medical facillity? ?‍?


I think the main problem is - would it stay that way under all conceiveable circumstancesat all times ?

'wooden holiday chalet'

Does not sound like the sort of place that the  non conducting location protection was envisaged for - what are you putting in there, I presume it is some sort of substation or similar with exposed basic insulation ?

Also how are you controlling and restricting access - permits ? Castell keys? 

If all you want to do is to miss the CPC off a few sockets, then it is not the right approach.

Would there be any sockets?


  - Andy.

Not a substation. Not a medical facility. Yes there will be sockets in the holiday chalet. The use will be closely monitored. Heating is by fixed wall panel heaters.


Z.

Yes there will be sockets in the holiday chalet.

Then you can't stop users introducing protective conductors into the location and you fall foul of regulation 418.1.3. (The bit after the socket risks becoming a 418.2 system instead). You also can't control extension leads being run outside.


  - Andy.

How is someone prevented from plugging an extension lead into a socket and running it to outside?

Zomm you are getting exceedingly close to becomming a very naughty boy

If it is a holiday chalet, and still being used as such by the general public, then, no. Your idea of 'closely controlled' access is not the same as will be expected. Warning signs, door interlocks, permits and tokens, training of all persons using the facility before entry is granted.


If it is an ex holiday chalet being repurposed to become a chamber for housing specialist high voltage  kit, then maybe.


The principle is that the voltage reached by any exposed metalwork is not a hazard because it is not possible to touch two pieces of metalwork with differing voltage levels at the same time. Care must be taken, however, to make sure that a dangerous  potential cannot be transmitted outside the location by the subsequent installation of a conductor such as a cable, a pipe or structural metalwork, indeed anything that penetrates the insulating enclosure.


Consider, if two faults to near exposed conductive parts occur from conductors at different potentials (such as a phase and a neutral or two phases ) dangerous potential differences could occur between exposed conductive parts, nothing will trip.


Double pole fuses or double pole breaking circuit breakers are used for ADS protection in non-conducting locations as the idea of neutral being safer than live is lost, the user is as likely to be at live potential as any other.


I would not expect to see any kind of 3 pin sockets or any kind of metal light fitting requiring a CPC, if out of reach or not.


A notice must be erected to state that the non-conducting location exists, and giving details of the person in charge (supervising) who alone has authority to authorize access to the facility and any experiment or testing  to be undertaken within, and to be responsible for what equipment may be used in the location.

I'd expect records of training to be signed by the users and kept by the supervisor, along with results of inspections and a list of authorized equipment. All such records to be maintained in a condition available for inspection by the authorities as an audit trail in case of incident.


Non-conducting locations are rarely the best solution to the safety problem and so are most unusual, and their use must be limited to situations where there is continuous and proper supervision to ensure that the safety requirements are fully met and are properly maintained, and in my personal view they should be restricted to situations where no more reliable system of ensuring safety is possible.