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MOV protection

ivak245

Jun 11, 2021
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Jun 11, 2021
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When an MOV is exposed to an over-voltage (fault condition), do they normally fail to an open or short circuit?
 

bertus

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Nov 8, 2019
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Hello,

From the page:
For sustained steady-state overvoltages, a typical test requirement for a traditional MOV withstands 150% of its rated voltage for a given duration.
But MOVs may fail to a short-circuit condition when subjected to sustained steady-state overvoltages above this level.

https://www.powerelectronics.com/content/article/21855678/thermally-protected-movs-resist-overvoltage-failures#:~:text=The prominent failure mode for the MOV is,its maximum energy capacity and enters thermal runaway.

More info here:
https://www.littelfuse.com/~/media/...stors_in_spd_and_ac_line_application_note.pdf

Bertus
 
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