This could be a very simple question, but after many years in electrical engineering I suddenly realized that can not determine voltage classification of the VFD system (enclosure) that has input voltage 575V AC and DC bus voltage 850 V DC. Is such equipment classification considered to be below 600V per NEC or above 600V? Is the rating assignment based on input voltage or actually maximum voltage that exists in the system?
Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Equipment voltage ratings
- Thread starter thinker
- Start date
Since the LV cutoff went from 600 V to 1000 V in the 2014 NEC, I'm wondering why you're worrying about this?
By the way, the VFD would be below 600 V per NEC. The voltages inside don't matter. Consider that CRT-based TV sets were 115 V loads, but produced thousands of volts internally to operate the CRT. Regardless of the VFD rating, though, wouldn't you be connecting the VFD to a 600 V system?
xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
By the way, the VFD would be below 600 V per NEC. The voltages inside don't matter. Consider that CRT-based TV sets were 115 V loads, but produced thousands of volts internally to operate the CRT. Regardless of the VFD rating, though, wouldn't you be connecting the VFD to a 600 V system?
xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
- Status
Similar threads
- Locked
- Question
- Locked
- Question