×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

480 voltage

480 voltage

480 voltage

(OP)
what is the min. air gap needed to prevent 480 volt AC from arcing?

RE: 480 voltage

Scary question without more information but...

Your Dielectric Withstand Test uses 677 Vdc (or 479 Vac). If the test passes it will confirm that the smallest gap between exposed conductors in the cable is likely greater than 0.003 inches (0.08 mm). If the test fails you may have a gap less than 0.003 inches (0.08 mm). If the DWV test is done in helium then the test might detect a gap as large as 0.083 inches (2.11 mm).  

RE: 480 voltage

(OP)
This is for a heater bank in a oven that is going through a pass through. I am talking about phase to ground and I would also like to know about phase to phase. Is there any standard for air gaps ver. voltage? I have a probe that is about 1/8" away from ground and I do not want it to arc.

RE: 480 voltage

Post your question in the electrical forum. There are probably code required air gaps that far larger than than what you would calculate based on first principles. Why would you not use a ceramic insulator on a wire passing through a steel wall?

RE: 480 voltage

(OP)
I am using a ceramic insulator, but where the probes passes throuh the wall the probes gets reall close to the fitting I have that it mounts to.

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!


Resources