On Sat, 25 Feb 2006 15:22, Andy George wrote: > Volker Kuhlmann wrote: > >>Some appliances (including dishwashers?) are not suitable to run off > >> RCDs. > > > >What's the reason given for this? > > > >Anything involving water would be the first thingeme I'd spend an RCD > >on. > > > >Volker > > At a guess, amp rating. I've seen devices with a Crowbar circuit, a > device that, if an appliance reaches 80% of rated load very quickly > (such as turning heaters on, to heat water, or dry dishes, or the likes) > the protection device assumes this is the ramp-up to a direct short > (Run-away amp load), and slams the gate shut... > > Clever, but terrifically inconvenient
Nope, not current rating. The RCDs fitted to a house switchboard are typically RCDs (residual current devices) and not RCDOs (residual current devices with overload protection). They have a maximum current breaking capacity, but high current does not cause them to trip, earth leakage current does. Now I have seen a bunch of computers trip an RCD, caused by the RF suppression capacitors in the power supplies, but there were 40 computers on the same circuit... Invest in a UPS? Cheers, Wayne
