No, the whole point of RLV (Reduced Low Voltage) is that the credible touch voltage in any significant fault is almost always less than 50V so the safe touch time is 'for ever'. No safety of life speed ADS is needed.
The slight issue is that some folk like their RLV installation to meet BS7671 when really the whole philosophy of rapid ADS versus safety to touch is quite different. BS 7671 is inspired by a Euro-standard, and generally the non UK authors of the base standard are are not familiar with our 55-0-55 RLV approach, or its 3 phase devilish variant the 66.6-0-66.6 with something like 100-120volts between two phases 120 degrees apart?. I know it's not normally 66.6 volts really but it does raise eyebrows with my German speaking friends who have been known to call it something that translates to that. As well as muttering about silly island monkeys when they think I'm not listening.
No, the whole point of RLV (Reduced Low Voltage) is that the credible touch voltage in any significant fault is almost always less than 50V so the safe touch time is 'for ever'. No safety of life speed ADS is needed.
The slight issue is that some folk like their RLV installation to meet BS7671 when really the whole philosophy of rapid ADS versus safety to touch is quite different. BS 7671 is inspired by a Euro-standard, and generally the non UK authors of the base standard are are not familiar with our 55-0-55 RLV approach, or its 3 phase devilish variant the 66.6-0-66.6 with something like 100-120volts between two phases 120 degrees apart?. I know it's not normally 66.6 volts really but it does raise eyebrows with my German speaking friends who have been known to call it something that translates to that. As well as muttering about silly island monkeys when they think I'm not listening.
