NEC 2023 High Voltage Articles

[yesterlectric]

I saw a pre-recorded webinar a while back that mentioned that a number of the proposed articles for medium voltage in the 2023 NEC were not on the normal first draft report but were under some kind of "global inputs" from the "long range planning task group." I can't find any such proposed articles. Is there still a separate section for articles that are being proposed for the NEC in 2023 that aren't on the regular first draft report? For instance, 210.1 has an informational note saying reference article 235 for over 1KVAC/1.5KVDC. No article 235 exists in the first draft report. Are there other proposed articles hiding somewhere or did I stumble upon a mistake?

 

[don_resqcapt19]

There are a lot of issues like that to be corrected in the second draft. Some of the high voltage stuff made it and some did not.

 

[paulengr]

It is my understanding that internationally 1 kV is considered the cutoff between low and high voltage, more specifically matching the IEEE definition of medium voltage. There is an effort underway to move up the 600 V limit where possible to 1 kV. There is now strong support for this in PV solar equipment. The limitation is existing OSHA regulations based on the 1986 NEC that are glacially slow to change so NEC is attempting to balance the two.

Personally I think it would be more beneficial to move up the shielded cable requirement to something more realistic like 3 kV since it is pretty well known 2400 V systems do not require shielded cable. Corona damage doesn’t occur until at least 2.5 kV. Personally I’m all for outright deleting this regulation because I’ve seen tons of damage from improper installs whether shielded cable was used or not, even from factory built equipment by “reputable” suppliers such as GE and Westinghouse. You need to know what you are doing to work in MV, period. Perhaps Saskatchewan has it right in making “high voltage” training mandatory requiring certification.