New DEC museum entry :D

Tony Duell ard at
Wed Feb 21 18:39:55 CST 2007

> On 21/2/07 06:11, "Bob Bradlee" <caveguy at> wrote:
> > would heat up and pop, I swaped the breaker out with a different one of the
> > same size and it that held just
> > fine. The circuit I moved the week breaker to, normally only runs 7 or 8 amps
> > and it never failed with the
> > light load.
> Thing is, if it was something like that then the 32A breaker running the
> upstairs ring main would pop rather than the whole house, that to me shows
> more of a sudden leak to earth than anything else. It's still odd that the
> Pro's own PSU breaker doesn't pop before anything else does.

That 32A MCB and the breaker in the Pro are current-operated devices. 
I'll bet the main switch is an RCD (and not current operated at all), and 
what's tripping the latter is an earth leakage problem.

Thing is, some older mains filters have a fairly high earth current 
anyway (one reason I don't want an RCD anywhere near the mains to my 
workbench). SO there may not be an actual fault. But replaceing the 
filter (or the capacitors, possibly with lower value ones) might get it 

The 5 minute delay is a puzzler though...


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