What kind of cross screwdriver should I use for the relay line?
If is such a function, can be, he can be in series with the load circuit, but not parallel, because each contact impedance and will not the same as to the current uneven and misoperation, select the model must consider the load is AC or DC, what is the requirement of the current action. The biggest I've ever used is AC150A.
Do you require the current relay to operate when the transformer is driving the load?.