Quote Originally Posted by DobeyMan
Is it correct that the terms "разомкнут" and "замкнут" should be used to describe a circuit breaker ("прерыватель цепи" or "размыкатель цепи") that is open or closed, rather than "открыт" or "закрыт"?
basically, yes with circuits you say it's разомкнута when there's a break in it and замкнута when there's none, a short circuit is короткое замыкание.
At home if you have circuit breakers rather than fuses most people still call them пробки, sometimes пробки автоматы even though they don't melt, but just switch off automatically you can switch them back on later.