Power Quality

Sag or Undervoltage

Description

A decrease in voltage

Duration

Milliseconds to a few seconds
Undervoltages are Sags that are longer than a few seconds

Causes

Major equipment start-up or shutdown
Short circuits (fault clearing)
Undersized electrical circuit

Effect

Memory loss or data errors
Dim or bright lights
Shrinking display screens
Equipment shutdown/Reset

Possible Solutions

Relocate computer to a different electrical circuit
Voltage regulator
Constant Voltage Transformer (Ferro-resonant transformer)
Power conditioner
Uninterruptible power supply
Motor Generator
Capacitor/Flywheel/Superconductor storage