ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Hot ground????????

To quote Mr. Spock, "Fascinating!"

Assuming that both RCDs aren't faulty, the loop impedance would need to rise to a substantial level to prevent them from tripping (something over 2200 ohms for the 100mA type nad 7.3K for the 30mA one). With TN-C-S the only practical way I can see for this to happen is a very bad bond between neutral and ground at the service entrance.

The only problem is that with the current down to less than 30mA, I wouldn't expect to see that much of a spark when lifting the dishwasher ground.