Skip to main content

Below are different types of power disturbances with a brief explanation of each. Having a basic understanding of the different types and their causes is helpful when developing a prevention plan specific to your business.


1. Circuit switching

Occurs when there is a sudden change to an electrical circuit as a result of equipment use, changes in utility power supply or damaged power lines.


2. Surges

A short-term increase in voltage, which can damage delicate electronic components and insulation in motors causing immediate failure or reducing their operating life. Small power surges may happen several times a day as a result of electrical devices starting up or shutting down and diverting electricity to and from other appliances on your premises or adjacent premises.


3. Spikes

Spikes are a short, instantaneous increase in voltage, reaching as high as several thousand volts. A spike may cause catastrophic damage to electronic components and data.


4. Blackouts

A blackout is a sudden and total loss of utility power. If power is not restored correctly after a blackout, voltages exceeding several times the primary power level may be generated which can create a power spike.


5. Sags or Brownouts

A sag or brownout is a short-term decrease in voltage which may lead to tripped computers, system crashes and loss of data. Sags and brownouts can affect transformers, light ballasts and electric motors, causing them to run hot, which reduces their operating life span and efficiency.


6. Lightning

Lightning is the most disruptive cause of power surges. Damage can occur from a direct lightning strike or an induced surge (a strike occurring somewhere away from the electrical system). An induced lightning surge on overhead electrical distribution wires can deliver as much as 100,000 volts. Lightning surges can also enter buildings via other metal conductors like water lines, telephone lines, unshielded CAT cable or TV cables.