2300V Motor Cable per NEC 310.6 1

[JBUDA54]

I am having difficulty interpreting the NEC 310.6 Article. One of my co-workers told me that only 4160V motors are required to have shielded cables to the motor. He explains that the 2000V and above is a line to ground rating and that 2300V motors would fall in the under 2000V case since its L-N rating is 1328V. Is this correct? I believe it is but want to get others to throw in their 2 cents. Thanks in advance. I have listed two references that support's my co workers case but both articles do not mention 2300V motors. Are there any other good references?

References

http://ecmweb.com/nec/electric_behind_nec_changes_3/

http://search2.southwire.com/search?q=cache:w9tQ9YWiqggJ:

http://www.southwire.com/processGet...xystylesheet=southwire_frontend&oe=ISO-8859-1

 

[7anoter4]

Attached find another article in which the author explained very clear that the cables manufactured according UL 1072 -Standard for Medium-Voltage Power Cables- as 5 Kv cable will be as follows:
"Approximately half of all “5 kV” circuits actually operate at a voltage of 4,160 volts.
These and similar circuits will now have to be wired with shielded rather than nonshielded cables. Most of the remaining “5 kV” circuits actually operate at 2,300 volts or similar voltages. These lower voltage circuits can continue to be wired with non-shielded cables as long as the cables are Listed as Type MV-90 or MV-105 cables by a qualified testing laboratory ".
See :

http://www.anixter.com/AXECOM/AXEDo...571D80067147A/$file/5kVNonshielded.6.2006.pdf

That means new 2005 NEC is referring to L-L voltage and not to L-N voltage.
Regards

 

[JBUDA54]

I noticed the hyperlink was disconnected but I did visit that site and it is a great reference. Thanks 7anoter4!!!