al hildenbrand
Senior Member
- Location
- Minnesota
- Occupation
- Electrical Contractor, Electrical Consultant, Electrical Engineer
Re: GFCI for Motor
A brown out will result in the trigger circuit not receiving enough energy to operate the breaker trip mechanism. Also, at some point, the applied voltage will be low enough that the solid state devices in the detection circuit connected to the output of the current transformer will move out of a useful location on their operating curves, effectively lobotomizing them. Which happens first will be a function of the particular manufacturer's assembly.
Simply put, the low voltages experienced during a brownout will decrease or defeat the successful operation of the ground fault detection of the device. Solid state devices tolerate this quite well.
The over voltage is another matter. As I think about it, it is probably a shrewd and deliberate circuit design that has given you the three expensive paperweights. Designing the circuit to fail at High Leg voltages to neutral is, in effect, an electronic rejection feature, helping to prevent misapplication of the breaker.
A brown out will result in the trigger circuit not receiving enough energy to operate the breaker trip mechanism. Also, at some point, the applied voltage will be low enough that the solid state devices in the detection circuit connected to the output of the current transformer will move out of a useful location on their operating curves, effectively lobotomizing them. Which happens first will be a function of the particular manufacturer's assembly.
Simply put, the low voltages experienced during a brownout will decrease or defeat the successful operation of the ground fault detection of the device. Solid state devices tolerate this quite well.
The over voltage is another matter. As I think about it, it is probably a shrewd and deliberate circuit design that has given you the three expensive paperweights. Designing the circuit to fail at High Leg voltages to neutral is, in effect, an electronic rejection feature, helping to prevent misapplication of the breaker.