The DNO network system categorised as Hot site or Cold site (430V or 650V ~ in case operating voltage of 33kV with sensitive earth faults cleared within 200ms). My submission is the standard always talks about the voltage (i.e pressure) or 30mA ELCB limits in case of housing earth leakage protection(i.e current). I presume either voltage or current are not alone cause for safety hazard. It is the product i.e voltage*current or V*I*t which causes burns on human body. Hence may i suggest in this forum to review this and consider the subject resistivity+ time aspects while calculating the "Step & touch power / energy" rather than "Step & touch voltage" as is being mentioned in the earthing standards. The additional variables of resistivity& time would help us to choose the appropriate insulating materials and relay settings and enhance human safety. Happy to discuss further, to bring this idea to shape and benefit wider community.
The DNO network system categorised as Hot site or Cold site (430V or 650V ~ in case operating voltage of 33kV with sensitive earth faults cleared within 200ms). My submission is the standard always talks about the voltage (i.e pressure) or 30mA ELCB limits in case of housing earth leakage protection(i.e current). I presume either voltage or current are not alone cause for safety hazard. It is the product i.e voltage*current or V*I*t which causes burns on human body. Hence may i suggest in this forum to review this and consider the subject resistivity+ time aspects while calculating the "Step & touch power / energy" rather than "Step & touch voltage" as is being mentioned in the earthing standards. The additional variables of resistivity& time would help us to choose the appropriate insulating materials and relay settings and enhance human safety. Happy to discuss further, to bring this idea to shape and benefit wider community.
It is not just body burns that we are concerned about. The heart and breathing can be affected too. Chapter 41 of B.S. 7671 deals with this matter, shock protection of humans and livestock. Much research has already been undertaken and published about electric shocks and their affects on the human body. This is a question that will cause debate on the I.E.T's B.S. 7671 Wiring and Regulations Forum. You should get much response. Not many souls pass through here in Netherworld it is a bit quiet. Good for a sleep though.
The DNO network system categorised as Hot site or Cold site (430V or 650V ~ in case operating voltage of 33kV with sensitive earth faults cleared within 200ms). My submission is the standard always talks about the voltage (i.e pressure) or 30mA ELCB limits in case of housing earth leakage protection(i.e current). I presume either voltage or current are not alone cause for safety hazard. It is the product i.e voltage*current or V*I*t which causes burns on human body. Hence may i suggest in this forum to review this and consider the subject resistivity+ time aspects while calculating the "Step & touch power / energy" rather than "Step & touch voltage" as is being mentioned in the earthing standards. The additional variables of resistivity& time would help us to choose the appropriate insulating materials and relay settings and enhance human safety. Happy to discuss further, to bring this idea to shape and benefit wider community.
It is not just body burns that we are concerned about. The heart and breathing can be affected too. Chapter 41 of B.S. 7671 deals with this matter, shock protection of humans and livestock. Much research has already been undertaken and published about electric shocks and their affects on the human body. This is a question that will cause debate on the I.E.T's B.S. 7671 Wiring and Regulations Forum. You should get much response. Not many souls pass through here in Netherworld it is a bit quiet. Good for a sleep though.
