From the Power Systems Engineering Committee:

https://site.ieee.org/ias-icps/

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Article 450 TRANSFORMERS AND TRANSFORMER VAULTSP3001.2 is the Recommended Practice for Evaluating the Electrical Service Requirements of Industrial and Commercial Power Systems.  P3001.2/D3 was balloted.  The task group has completed work on the  majority of the ballot comments (see attached).  Also attached is a preliminary marked up copy of P3001.2/D4 which contains the revisions made based on the ballot comments.  I have two tasks for the working group, which I am requesting by email in lieu of setting up a teleconference:

• Please review the comment resolution file, and the D4 draft as needed, and please confirm your concurrence with the resolutions.  I agree with the comment resolutions that you provided.

• There are four  unresolved items identified by yellow highlighting in the Disposition Detail column.   The task group would like input on these four items.

o   Two concern comments regarding reliability and renewable and/or distributed generation.  The comment seems questionable, and some initial thoughts on this are in the Disposition Detail column.  It might be easier to get a working  group consensus on this in a teleconference.

4.2.3.1 Disposition Detail – I believe you are correct with this statement.

4.2.3.2 Disposition Detail – I also believe that you are correct with this statement.

9.6.1 & 9.6.2 Disposition Detail – As you noted, there are some references, but nothing that is consistent.  NEC Article 450 provides some specific requirements, as noted in the attached copy of the article. The best solution to this is to refer to State and Local requirements, or the Authority Having Jurisdiction.

o   Two issues concern concrete thickness ….sidewalks above vaults and vault wall thickness.  It is assumed that this content may have come out of the old Gray Book working group, none of whom appear to still be around.  The web has been researched to find substantiation of the figures, and none found yet.  The working group is requested to help decide what to do with this material.  If you know someone who is familiar with this material, please obtain their assistance on this.

See the attached requirements from the National Electrical Code, Article 450TRANSFORMERS AND TRANSFORMER VAULTS (INCLUDING SECONDARY TIES).

I would appreciate a reply back by 8/22/16 so that we can get the  next draft recirculated t the ballot group soon.

Best regards,

Gary H. Fox, PE
Chair, 3001 WG