Table 41.1 Assumed Touch Voltage

Nathaniel:

ProMbrooke:

Any idea as to why IEC TR 1200-413 is retired?

No. I've wondered too. I was surprised even when I first saw it, as I've not come across other cases of such a detailed 'technical report' devoted to explaining why certain choices were made in a standard.  Perhaps it's not fashionable now to bother with public explanations. The IEC and national standards bodies appear happy to carry on selling this retired publication at a hefty price. (IEC says 'withdrawn').

 

Well, I'm prepared to show my inference in great length, for the world to see, for the benefit of all humanity. :) Hiding the technical reasoning is both a crime and unethical when used to make what is used as law all over the globe. And I know why the IEC has gone into hiding technical aspects: because AFDDs are just the start to a long marketing concept. If you can mandated it, then it will sell. But that is for another thread.


Me personally I've been compelled to come up with my own code and my own standards. I would very much like something that will one day supersede all IEC and NEC based codes.


The IEC TR 1200-413 makes a very good argument for faster disconnection times in wet locations in annex C but for some reason this has not made itself into BS7671. The US NEC also goes to great lengths to put GFCIs into kitchens, laundry rooms, unfinished basements, garages, ect all considered low skin conductivity locations in the eyes of the NFPA.


Because BS1363 sockets will not open without an earth pin, and are not likely accept schuko sockets, in my view this counts as assurance of the CPC path. Hence why RCDs in the UK were delayed into the 90s early 2000s. As such RCDs are not intended to be the primary means of protecting against indirect contact.And in general that should hold true for any supply. The primary means in my opinion should be in the ADS, achieved only though loop impedance ie high conductance. The voltage at the point of fault to remote earth determining the maximum duration which an MCB or fuse is permitted to stay closed.  


I'd be ok with a smaller CPC provided faster disconnection (which is usually the norm with most MCBs), however I personally think this should be avoided on circuits 63 amps and below on the count high Ze, such as that of a generator hook up, can cause annealing and in turn future compromising of the CPC path.      


   

Nathaniel:

ProMbrooke:

Any idea as to why IEC TR 1200-413 is retired?

No. I've wondered too. I was surprised even when I first saw it, as I've not come across other cases of such a detailed 'technical report' devoted to explaining why certain choices were made in a standard.  Perhaps it's not fashionable now to bother with public explanations. The IEC and national standards bodies appear happy to carry on selling this retired publication at a hefty price. (IEC says 'withdrawn').

 

Well, I'm prepared to show my inference in great length, for the world to see, for the benefit of all humanity. :) Hiding the technical reasoning is both a crime and unethical when used to make what is used as law all over the globe. And I know why the IEC has gone into hiding technical aspects: because AFDDs are just the start to a long marketing concept. If you can mandated it, then it will sell. But that is for another thread.


Me personally I've been compelled to come up with my own code and my own standards. I would very much like something that will one day supersede all IEC and NEC based codes.


The IEC TR 1200-413 makes a very good argument for faster disconnection times in wet locations in annex C but for some reason this has not made itself into BS7671. The US NEC also goes to great lengths to put GFCIs into kitchens, laundry rooms, unfinished basements, garages, ect all considered low skin conductivity locations in the eyes of the NFPA.


Because BS1363 sockets will not open without an earth pin, and are not likely accept schuko sockets, in my view this counts as assurance of the CPC path. Hence why RCDs in the UK were delayed into the 90s early 2000s. As such RCDs are not intended to be the primary means of protecting against indirect contact.And in general that should hold true for any supply. The primary means in my opinion should be in the ADS, achieved only though loop impedance ie high conductance. The voltage at the point of fault to remote earth determining the maximum duration which an MCB or fuse is permitted to stay closed.  


I'd be ok with a smaller CPC provided faster disconnection (which is usually the norm with most MCBs), however I personally think this should be avoided on circuits 63 amps and below on the count high Ze, such as that of a generator hook up, can cause annealing and in turn future compromising of the CPC path.