Power spikes? Rig rebooted due to PSU protection? Tell me which one would do that instead of just shut down PSU itself:
OVP (Over Voltage Protection)
UVP (Under Voltage Protection)
OCP (Over Current Protection)
OPP (Over Power Protection)
and SCP (Short Circuit Protection)
My BIOS is set to automatically power itself back on after shutdowns / power losses / reboots etc.