Post date: Feb 11, 2018 1:59:52 PM
If your generator does not have a neutral connection, the wiring needs to be modified a bit for load switching, and frequency/voltage measurement
The loads can be connected to their own neutral point, as long as they are balanced. Connect the PCB neutral with the common center lead of all loads. (Star or Y wiring)
If you want to connect the loads Line-Line (delta or Δ wiring), then the switching has to be done with SSRs.
2 options
- create your own virtual common neutral with the help of a Y resistor network. 33kOhm 5W resistors will do.
or create the common neutral with transformers.
- declare one of the Lines as common reference point, connect it to PCB neutral, and measure L-L voltage. In this case, you can only measure 2 Line voltages. Also add 1MOhm resistors to each mains line input, to increase the voltage rating. ATTENTION in this case the PCB carries line voltage!
If you want to avoid line voltage on the PCB, insert transformers between Line and PCB.