How to specify the phase shift in electric currents (ec)

Hi,

I try to reproduce the 3-phase cable simulation as shown in
www.youtube.com/watch?v=ZCLcbSQB1-Q

I used the electric currents physics and time-dependent. How to specify the phase shift among the three rods? Using "Time-dependent" don't allow me to specify the frequency. I attached the mph files here also. Any suggestion? Thanks in advance.

Jinxiang