Table 41.1 Assumed Touch Voltage

Well, being old enough to remember 1981, though not old enough to vote at the time...    I can recall the RCDs being heavily sold for garden cables in terms of the cut cord to the hedge trimmer sort of accidents - i.e. the ones where the victim is in series with the fault path to ground, and the CPC is not really part of the equation.

The EEB part of idea of EEBADS (i.e. the earthed equiotential bonding ) which indoors was all the rage at the time, does not really work outside,  in the same way we had folk telling us not to include the area of the lawn in the 100m2 served by the ring, even if the socket for the lawnmower was say a socket by the back door. 

(if you do include the lawn area you find it plays havoc with the diversity and maximum demand sums.)


It is also important to realise that the regs were not as closely followed as they are today, and in a pre-internet era, with the current full-on  computer connectivity and  'instant gratification'  not even a dream,  any change took a  long time to filter through to those working more "out in the sticks" as  it were.

So a regs change in the early 1980s was probably not filtering through to all electricians  for a good few years.    Another similar case would be earthed lighting circuits, supposedly reuired from the late 1960s, but in reality many old sweats were either not connecting the CPC (cutting it back once the 2 core cable was used up) or just twisting it hopefully outside the joint boxes, until at least the mid 1970s.


My point is it may look like RCDs did not arrive until the 1990s, but in reality they appeared in the regs about  a decade earlier, but there were plenty of folk working to  the way they always had, blissfully unaware of changes for quite a while.

Mike.

Well, being old enough to remember 1981, though not old enough to vote at the time...    I can recall the RCDs being heavily sold for garden cables in terms of the cut cord to the hedge trimmer sort of accidents - i.e. the ones where the victim is in series with the fault path to ground, and the CPC is not really part of the equation.

The EEB part of idea of EEBADS (i.e. the earthed equiotential bonding ) which indoors was all the rage at the time, does not really work outside,  in the same way we had folk telling us not to include the area of the lawn in the 100m2 served by the ring, even if the socket for the lawnmower was say a socket by the back door. 

(if you do include the lawn area you find it plays havoc with the diversity and maximum demand sums.)


It is also important to realise that the regs were not as closely followed as they are today, and in a pre-internet era, with the current full-on  computer connectivity and  'instant gratification'  not even a dream,  any change took a  long time to filter through to those working more "out in the sticks" as  it were.

So a regs change in the early 1980s was probably not filtering through to all electricians  for a good few years.    Another similar case would be earthed lighting circuits, supposedly reuired from the late 1960s, but in reality many old sweats were either not connecting the CPC (cutting it back once the 2 core cable was used up) or just twisting it hopefully outside the joint boxes, until at least the mid 1970s.


My point is it may look like RCDs did not arrive until the 1990s, but in reality they appeared in the regs about  a decade earlier, but there were plenty of folk working to  the way they always had, blissfully unaware of changes for quite a while.

Mike.