You are correct, Brian, but I never understood the logic. Everyone knows that civil servants are expendable. Frederick, I rather like RCD's. They are not the answer to all fires of electrical origin, but they help. They do tend to nuisance trip though, which is why a lot of electrical engineers are still against them. This is mainly because they are set at 30mA, which is appropriate for shock protection. I do not believe you need them set that low if it were just for fire protection. One of my few successes in life was, back in the 1970s. persuading the IEE to require RCDs on ceiling heating systems. I arranged some test work, which showed that an RCD would prevent a fire if the happy wee DIY man put a nail through the ceiling and into the cable, and it would save him from electrocution. (The success was short-lived because ceiling heating had its day very quickly anyway when people realized they were paying to heat the Milky Way and got huge bills as a result!)