Power Quality Problems

Power Quality Problems can be everything from too little power, too much power, or "dirty" power feeding your equipment at just the right voltage.  Before you can fix the problems, you need to understand what they are.  We have pulled together this simple overview to give you an idea of the problems that you could be facing.

The basic power quality problems are listed below. 


A short term decrease in voltage


A brown out is like a sag, but for a longer length of time.  Power is still being fed by the utility, but it is below a voltage that is safe for your equipment.


A Blackout, or a complete power outage is when the utility stops feeding any voltage to your loads.


A spike is a fast impulse that dramatically increases voltage instantaneously.  This huge impulse can wreak havoc on sensitive equipment.


A surge is a dramatic increase in voltage that is longer than the instantaneous spike (typically lasting more than 1/120th of a second).


Noise is unwanted distortion on the line.  Noise can be either from Electro Magnetic Interference (EMI) or Radio Frequency Interference (RFI).  

Over voltage

An over voltage occurs when the utility is feeding a voltage that is higher than an acceptable range for your load for a period of time that exceeds


Harmonics cause distortion to the sine wave, which can cause many different problems

Frequency Fluctuation

variations in the frequency that can cause equipment problems

These are the common power problems that most companies face. These can be caused both externally and internally.  While many people point to the utility for all their power problems, the bulk of power quality issues originate inside your facility (between 70 to 80% depending on which report you look at).  The reason for this is a combination of modern technology and energy efficiency.  Computers, modern lighting, Variable Speed Drives, and other devices that make us more effective and more efficient can damage other equipment throughout your facility.

Be sure to look at the specific causes of the above problems on our Power Quality Causes Page.

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