Terry Boblitt
Member
looking for someting that will detect current change in a 3 phase system. I need to monitor 10-30 amp load on induction heaters.
DwalterE said:If it's balance between the phases that you're concerned with, pass all three phase leads through a single CT (current transformer). The resulting signal will represent the imbalance between the phases.
milldrone said:I'm not a current monitoring expert but wouldn't this only detect a ground fault?
At first glance I thought running all 3 phases thru a CT was good idea. Thinking more on it and demonstrated in your case of a single phase load on 3 phase all the "goes out" currents were balanced by "goes in" current so there was no reading. Would work if there were leakage to ground or some other "goes back" path ie neutral not run thru CT.milldrone said:I'm not a current monitoring expert but wouldn't this only detect a ground fault? I tried this in my shop with a single phase heater and three phase power and got no reading.
Alaric said:I am wondering about the use of terminology here (or perhaps I'm just confused). The first post indicates induction heating. Post 8 says 240V 60hz. 60hz wouldn't be very effective for induction heating. Are you sure its not resistive heating? Or is 240V 60hz the supply to an induction heating inverter?
allscott said:Me too, all the induction heaters I've worked with generally run in the khz or MHZ range.