I'm trying to calculate the resistors in an AC dummy load for a 3-ph system.
A simplified schematic can be found below. The idea is to switch (with regular AC 1-ph contactors) some resistors on each phase, the middle point being the neutral point.
The generator has a line-to-line Voltage of 280V and we're trying to dissipate a maximum of 60kW.
I'm using the following formula : I = P/(sqrt(3)*U) = 60000/(sqrt(3)*280) = 123A
==> I'm trying to have 123A per phase in order to dissipate 60kW.
R=U/I = 2,276 Ohms ==> Am I correct in assuming I have to have a 20kW resistor of this value on each phase? (of course divided between several resistors in order to be able to reach intermediate power values via the contactors).
Thanks for the input!