Current relay

 

— protective devices that automatically turn off the protected area when the consumed current exceeds the specified parameters. It is similar in purpose to circuit breakers, however, firstly, the current relays can also respond to a decrease in current, and secondly, such a device may not work instantly, but after a certain time. It makes sense to install a current relay where short-term operation at high currents is allowed, however, the time of this operation must be limited, and also where long-term idle operation at low currents is undesirable. A classic example is connecting a power-controlled motor: the current at maximum power can be set as an upper limit, and the lower limit can be set just above the no-load current. The shutdown time in such devices, usually, can be set within a few minutes.