#6 AWG MV-105 wire
- Thread starter Twophase
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Typo. Meant to say 200HP. Still used #6 because #8 seemed too small for comfort....
Uncommon. Maybe for some transformer feeders but otherwise wouldn’t be used. Even then inside gear it will be unshielded jumper wire. Outside it’s usually not insulated.
The general rule (IEEE Red Book) is that the cross over economically between MV and LV for motors is 500-1000 HP and that’s a 4160 argument. You are in the voltage class not generally used except above 5000 HP. Power electronics tends to push the upper end a little.
The issue is that insulation required greatly increases costs and sizes of the equipment and wiring as voltage increases whereas it decreases copper costs.
So conventional design calls for a fused switch, 6.9 kV to 600 or 480 transformer then a conventional starter and motor. I know of one case where they used 2300 V submersibles at 200 HP because that is the smallest diameter cable at 200 HP unshielded 4160 is larger overall even unshielded. Mining application so NEC is optional.
So yes very exotic what you are trying to do. Consider calling say Amercable of TF Cable. If you don’t mind buying 2000+ feet they will make you a batch.
kwired
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what is nameplate amps of this motor? guessing about 23-25 amps?
Yup. Pretty low, but it is a custom motor for the application.
Thanks for your reply. I am glad that there is no blatant NEC violation. I actually have a copy of the IEEE Red Book (as well as the Buff, Gray, White, and Orange books if they are relevant) do you have the reference? This is a good time for me to become more familiar with these standards.
Red book is one of those where the best thing is to read cover to cover. Should be required course for EEs. It covers basic system design principles and practices for industrial and commercial systems. There is a lot of “why things are the way they are”. It covers standard system voltages and voltage selection, basic system design issues such as choice of grounding systems. Everything else more or less gets into implementation details but none really cover design. For instance green book (grounding) describes every grounding system out there without ever covering why choose one over another.
kwired
Electron manager
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- NE Nebraska
I thought it was a magazine mostly targeted to women?
I thought it was a magazine mostly targeted to women?
Thats Redbook not IEEE Red book. Supposed to be for brides.
IEEE Std 141-1993, IEEE Recommended Practice for Electric Power Distribution for Industrial Plants (The IEEE Red Book)
IEEE Std 141-1993, IEEE Recommended Practice for Electric Power Distribution for Industrial Plants (The IEEE Red Book): Institute of Electrical and Electronics Engineers: 9781559373333: Amazon.com: Books
IEEE Std 141-1993, IEEE Recommended Practice for Electric Power Distribution for Industrial Plants (The IEEE Red Book) [Institute of Electrical and Electronics Engineers] on Amazon.com. *FREE* shipping on qualifying offers. IEEE Std 141-1993, IEEE Recommended Practice for Electric Power...
www.amazon.com
See, bright red cover. Part of the “color books series”. Each one has a colored cover.
kwired
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- NE Nebraska
You are too serious.
ramsy
Roger Ruhle dba NoFixNoPay
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kwired
Electron manager
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- NE Nebraska
Proper response from Paul was supposed to be "ha ha".
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