Hi Guys,
Yip, heard of this one too (disconnect the Protective Earth so as to stop the ECLB/RCD/RCBO - take your pick!) from tripping. Once had a case where this was done and tester/operator was receiving "mild tingles" (i.e. shocked like hell!). It revealed the knobs were conductive!
Solution: Not to disconnect the Earth, but to rather have a non RCD line (or to bypass the RCD) feeding the cooker for the burn-in period but to monitor the leakage current to ascertain the burn-in was complete. If an element failed (shorted) during this time it would either pop the fuse in the cooker (some older cookers had fuses per circuit) and/or trip the main current breaker (usually at the same time the filament tried to escape through the element casing!).
I have continued this practice through all cases of earth leakage problems (especially cookers) by bypassing the RCD but monitoring the leakage current. When the leakage falls below the required mA, return the circuit to normal (reinstate the RCD) and leave behind one very happy customer (and no-one shocked in the process). You'd be surprised at the number of central heating pumps that need this treatment too.
M.
