There seem to be many unintended consequences generated by the Amd 2 DPC. I wonder why it is US who sees them and not JPEL/64? Is it the lack of experience of JPEL/64 or is it something else?
I don't disagree with statement of cost regarding AFDDs, but I perhaps hold the view that, just like RCDs, the costs will come down and the devices will improve.
And once the devices have improved, and be shown to work, in the sense of reducing fires damage and fatality, and the costs come down to a manageable level, then, and only then, is the time to mandate them onto the majority of circuits in the standards.
If we look at the history of when RCDs came into the regs, this is happened gradually over more than 3 decades.
In 1981 the 15th edition (oh vexed matters of earthing) first required 30mA RCD for sockets supplied by a TT system, and for circuits intended to supply items to be used outdoors of less than 32A and likely to be touched. (Reg 471-13)
At that time VOELCBS were still accepted on TT systems Reg 471-15.
Now while over the next 10- 20 years TT systems slowly lost VOELCBs (regs changed 1984 ish ) and acquired RCDs, the idea that this RCD idea should be extended to include general sockets that might occasionally be used to power equipment outdoors did not really take off , and had to wait until the 16th edition 2001 to be tightened to " any socket that might reasonably supply portable equipment for use outdoors". Enter the mass installation of RCD sockets by the back door for the lawnmower in the garden.
Even by 2008, in the 17th edition, although RCD protection was now required for all sockets for use by ordinary persons, there was an opt out for specific items such as fridges and freezers, and for whole systems under appropriate supervision.
Not until the 18th edition have RCDs become ubiquitous. In the mean time they have also developed, types AC, A, B etc reflecting the fact that the original RCD designs were not good in all cases.
A similar phased approach for AFDDS would mandate them only for places where the risk of an arc doing more than self extinguish is credible, and where AFDDs stand some chance of performing an ADS function. The haste is indecent.
I don't disagree with statement of cost regarding AFDDs, but I perhaps hold the view that, just like RCDs, the costs will come down and the devices will improve.
And once the devices have improved, and be shown to work, in the sense of reducing fires damage and fatality, and the costs come down to a manageable level, then, and only then, is the time to mandate them onto the majority of circuits in the standards.
If we look at the history of when RCDs came into the regs, this is happened gradually over more than 3 decades.
In 1981 the 15th edition (oh vexed matters of earthing) first required 30mA RCD for sockets supplied by a TT system, and for circuits intended to supply items to be used outdoors of less than 32A and likely to be touched. (Reg 471-13)
At that time VOELCBS were still accepted on TT systems Reg 471-15.
Now while over the next 10- 20 years TT systems slowly lost VOELCBs (regs changed 1984 ish ) and acquired RCDs, the idea that this RCD idea should be extended to include general sockets that might occasionally be used to power equipment outdoors did not really take off , and had to wait until the 16th edition 2001 to be tightened to " any socket that might reasonably supply portable equipment for use outdoors". Enter the mass installation of RCD sockets by the back door for the lawnmower in the garden.
Even by 2008, in the 17th edition, although RCD protection was now required for all sockets for use by ordinary persons, there was an opt out for specific items such as fridges and freezers, and for whole systems under appropriate supervision.
Not until the 18th edition have RCDs become ubiquitous. In the mean time they have also developed, types AC, A, B etc reflecting the fact that the original RCD designs were not good in all cases.
A similar phased approach for AFDDS would mandate them only for places where the risk of an arc doing more than self extinguish is credible, and where AFDDs stand some chance of performing an ADS function. The haste is indecent.
