Power Excess
Spike –> Too much voltage for a short period of time.
Surge –> Too much voltage for a long period of time.

 Power Loss
Fault –> A momentary power outage.
Blackout –> A long power interruption.

Power Degradation
Sag or Dip –> A momentary low voltage.
Brownout –> A prolonged power supply that is below normal voltage.