You can no longer post new replies to this discussion. If you have a question you can start a new discussion
Table 41.1 Assumed Touch Voltage
Former Community Member
I am a bit confused by this. Why do the disconnection times in Table 41.1 appear to be based on a touch voltage of 100 volts rather than a touch voltage of 125 volts?
For example, 110% of 230= 253 volts. Assuming L and PE are of the same size and material, indirect contact touch voltage is 126.5 volts. Would 0.33 seconds not appear more realistic?
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 U.K. has had the benefit of Earth Leakage Circuit Breakers for many decades before the 90s. Now called R.C.D.s in the case of the current operated types. Initially Voltage Operated types then current operated types were used. Or have I taken your comments out of context.
Of course B.S. 7671 requires R.C.D.s to be the only source of protection from shock/earth faults in special locations like caravan parks, marinas and farms etc. where TT earthing is specified.
Of course if I am in contact with a severed flex, with L in contact with my left hand, and N in contact with my right hand at the same time, I am a gonner despite what type of protective device is used, if I am wearing isolating shoes.
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 U.K. has had the benefit of Earth Leakage Circuit Breakers for many decades before the 90s. Now called R.C.D.s in the case of the current operated types. Initially Voltage Operated types then current operated types were used. Or have I taken your comments out of context.
Of course B.S. 7671 requires R.C.D.s to be the only source of protection from shock/earth faults in special locations like caravan parks, marinas and farms etc. where TT earthing is specified.
Of course if I am in contact with a severed flex, with L in contact with my left hand, and N in contact with my right hand at the same time, I am a gonner despite what type of protective device is used, if I am wearing isolating shoes.
