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Magnitude & Frequency of Power Line Surges*
• 6,000 volt surges can occur up to 100 X per year
• 4,000 volt surges can occur up to 500 X per year
• 2,000 volt surges can occur up to 1,000 X per year
* According to the American National Standards Institute (ANSI) on power line surges
Sources of Power Line Surges:
• Normal Power Company Switching Activities
• Air Conditioners, Furnaces, Refrigerators Cycling On & Off
• Copy Machines, Elevators, Motors Starting & Stopping
• Lightning
New Page 9
Truth about MOVs
Industry experts estimate surge probabilities in terms of thousands of surge
occurrences. What do MOV manufacturers publish regarding their product's surge
capability?
This table shows three manufacturer's surge ratings for two popular sizes
of MOVs used in surge suppressors.
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Metal-Oxide Varistor Endurance Ratings
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Panasonic
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Siemens Components, Inc.
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Harris Semiconductor
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14mm MOV
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10 surges of 1,000 amps
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10 surges of 1,000 amps
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10 surges of 1,000 amps
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20mm MOV
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100 surges of 1,000 amps
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100 surges of 1,000 amps
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100 surges of 1,000 amps
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A "best case" rating is 100 surges - far under the new commercial
standard of 1000!
Will your surge protector stand up to a 1000 surges @ 6,000 volts, 3000 amps?
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