O PEN Devices and Supplies

Yassir Khalil said:

when do you think it will become a requirement to fit these devices on final circuits or supplies where metallic objects are connected, for example kitchen appliances or protective bonding conductors connected to pipe work or the use of appliances outside surely the disconnection of the all conductors and CPC and bonding conductors is requirement in the event of this fault occurring. Any Thoughts ?  

In practice ... never for equipment indoors (cpc's and main protective bonding control touch voltages, plus the open-PEN detection only really is intended to detect specific conditions which are not related to local touch voltages resulting from faults).

Whilst it may occasionally be useful in PME installations for equipment outdoors, in addition to thoughts above, if you consider something like a heat pump outdoors, it will likely have additional or fortuitous bonding via metallic pipework etc. and therefore the open-PEN will be useless (it may disconnect the cpc, but the bonding is still in place, so you will still get the PME touch voltage through the pipework.

The open-PEN detection is intended for a specific set of conditions, and shouldn't be confused with, or used for, any other purpose, including hot tubs. It is only recognized in BS 7671 for Section 722, and as stated above, if used in some other circumstances, especially where there is bonding (fortuitous or purposeful) downstream of the protective device, you may well be offering (selling) a device for a purpose it could never fulfil (now, I'm not an expert in customer sales legislation, but I think that's mis-selling, or mis-representation).

If the earth within a premises becomes live and your using an extension lead outside then with the possibility of you coming into contact with a point of true earth then potentially there is a risk. The bonding removes risk of touch voltage but what if the bonding conductors become live. 

All the replies to this post are great. Good to see how other minds work. Great responses 

If the earth within a premises becomes live and your using an extension lead outside then with the possibility of you coming into contact with a point of true earth then potentially there is a risk. The bonding removes risk of touch voltage but what if the bonding conductors become live. 

All the replies to this post are great. Good to see how other minds work. Great responses 

Yassir Khalil said:

The bonding removes risk of touch voltage but what if the bonding conductors become live. 

If this happens in a building, the arrangement should be such that all of the building rises in potential. There are exceptions discussed in Guidance Note 7 and Guidance Note 5. Outside a building, all bets are off, but there are other considerations as discussed in my previous post. Please could you qualify your statement which I quoted above?