POWER QUALITY CAUSES
Now that you know what the common power problems are, we will highlight the common causes to power problems. This does not list all the causes, but certainly the most common causes.
Externally you have the utility based issues
Too much demand on the grid
Weather - Lightning, storms, ice on the lines
Accidents - car accidents, construction accidents, plane accidents (and the planes always seem to hit the powerlines)
Earthquakes - Well, we are in California, and the earth does move. When the earth moves, power lines sometimes move more than they should. The result is your load is not being fed power.
Equipment failures - The infrastructure of the power grid that feeds us is getting older, and as it ages, and as the utilities are hurting for money, we are seeing more problems in the older equipment as it fails, as well as problems associated with the more timely maintenance that needs to be done.
Grid based switching - This is a phenomena that we are seeing more and more in California due to the deregulation of the power supply, and the fact that we might be switching who we are getting supplies from frequently. Another issue based on this is the fact that the power we are buying is traveling much further to get to us, so their is a much larger chance for problems on the lines, because they are going a much longer distance through much more equipment, with a higher chance of multiple switches.
Internally you are faced with
Motors - Elevators, robotic drives, fans, etc.
VSD (Variable Speed Drives) - VSDs are much better than the older systems, but they still can cause power disruptions as they turn on and off.
Lighting (HID, Fluorescent, etc.) - The power supplies in much of the modern lighting can cause huge issues with the power within a building.
Computers (Switch Mode Power Supplies) - Many older buildings were not designed to have huge amounts of computers within the walls.
Grounding - Many older buildings have inefficient or totally non existent grounding based on degradation of grounding electrodes.
UPS's, Generators, etc. - Much of the back up power equipment installed across the country actually cause power quality issues.
Factory equipment - Assembly lines, load banks, motors, welders, etc.
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This site was last updated 09/28/10
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