Common Power Problems

There are various common power problems that UPS (Uninterruptible Power Supply) units from APC are used to correct.

Power failure
Description: Total loss of utility power.
Typical damage: Causes electrical equipment to stop working.

Voltage sag
Description: Transient (short term) under-voltage.
Typical damage: Causes flickering of lights.

Voltage spike
Description: Transient (short term) over-voltage i.e. spike or peak.
Typical damage: Causes wear or acute damage to electronic equipment.

Under-voltage (brownout)
Description: Low line voltage for an extended period of time.
Typical damage: Causes overheating in motors.

Over-voltage
Description: Increased voltage for an extended period of time.
Typical damage: Causes light bulbs to fail.

Line noise
Description: Distortions superimposed on the power waveform.
Typical damage: Causes electro magnetic interference.

Frequency variation
Description: Deviation from the nominal frequency (50 or 60 Hz).
Typical damage: Causes motors to increase or decrease speed and line-driven clocks and timing devices to gain or lose time.

Switching transient
Description: Instantaneous undervoltage (notch) in the range of milliseconds to seconds.
Typical damage: May cause erratic behavior in some equipment, memory loss, data error, data loss and component stress.

Harmonic distortion
Description: Multiples of power frequency superimposed on the power waveform.
Typical damage: Causes excess heating in wiring and fuses.