×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Electrical

Electrical

Electrical

(OP)
I have a lineup of 4160V switch gear and we are installing 480V switch across from it. According to table 110.34(a) in the NEC handbook there should be a minimum of 5ft between them. Since this is an existing building and the switch is going to be new is there an exception that it can be less than 5ft for medium voltage? I know for low voltage there is an exception but I cannot find one for medium voltage.

RE: Electrical

Exception based on what? No NEC exception that I'm aware of.

RE: Electrical

Do you plan on having doors open and exposing live MV parts? 5ft is Condition 2, usually if there will not be exposed live parts, it is Condition 1, which is 4ft.

If you do plan on having live MV parts exposed when the doors are open, are the live parts themselves set back inside the gear? The measurement for Condition 2 is FROM the live parts, not the door of the gear.

What is the LV equipment? Could it be ordered in a fiberglass enclosure? That would not be “grounded”, so even if you plan on exposing the MV live parts, you would be back to Condition 1.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: Electrical

Rule of thumb, if the inspector measures the available clearance it isn’t enough.

I’ll see your silver lining and raise you two black clouds. - Protection Operations

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close