Sags   
When incoming line voltage drops to 80-85% of normal for a short period of time.  Typical causes are heavy equipment being turned on, large electrical motors being started, and switching of power mains (internal and utility).  In our increasingly digital age, this can be problematic because it can cause memory loss, data corruption or data errors as well as flickering lights and equipment shut-downs.

Swells  
The opposite of sags, swells or power surges occur when the incoming line voltage is higher than anticipated - typically 110% above normal.  These normally occur when heavy equipment is turned off, resulting in flickering lights, equipment shut-off, data errors or data corruption.

High-voltage spikes   
Occur when there is a sudden, rapid voltage peak of up to 6,000 volts.  Normally the result of nearby lightning strikes, high-voltage spikes can cause data loss and burned circuit boards.

Switching transients
These take place when there is an extremely rapid voltage peak of up to 20,000 volts with a duration of 10 to 100 microseconds - such a short duration that they often do not show up on normal electrical test equipment.  Common causes are starting & stopping of machinery, arcing faults and static discharge.  In addition, switching disturbances initiated by utilities to correct lien problems may occur several times a day.  Switching transients can cause data errors, memory loss and component stress that can lead to breakdown.

Frequency variation
This involves a change in frequency from the normally stable utility frequency of 50 or 60 Hz.  This may be caused by erratic operation of emergency generators or unstable frequency power sources, resulting in data loss, program failure, equipment lock-up or complete shut down.

Brownout
A steady lower voltage state.  During peak electrical demands in the summer, utilities may lower the voltage to limit maximum power because they cannot always meet the requirements.  

Black out
A power failure or zero-voltage condition that lasts for more than 2 cycles.  It may be caused by a tripped circuit breaker, power distribution failure or utility power failure.  Results can be data loss or corruption and equipment damage.

Harmonics
A term used to explain currents and voltages that have multiplied within an electrical system.  If harmonics are present, the sine wave will be distorted rather than smooth.  Harmonics manifest themselves in problems such as nuisance tripping of fuses and circuit breakers, overheating of electrical panels, and more.

Electrical line noise
Also defined as Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI) - this causes unwanted effects in the circuits of computer systems.  It can be caused by motors, relays, motor control devices, broadcast transmissions, microwave radiation and distant electrical storms.  Electrical line noise can result in equipment lock-up and data errors or data loss.


Put Your New Skill To Use!
Contact your local Staco Energy representative and discuss your current situation.  They'll help you clarify your issues and guide you to the correct solution to your power quality challenges.

For additional questions or frequently asked questions visit www.stacoenergy.com and download our
 Guide to Power Quality (.pdf)