Relay-controlled Fan Transient Question
It appears that your AC/DC converter cannot handle the high frequency spikes and passes them through.  You need to eliminate them at the input to the converter (ps1, ps2).  You need a small AC cap to bypass the noise to ground.  I would start with a .01uf, 250v AC cap, right across the converter input pins, and see the resultant effect.
Make sure the fan cap is connected across the white and black wires, and the green wire to x2-1 and x2-2.