×
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

Substation Grounding

Substation Grounding

Substation Grounding

(OP)
We are doing a substation design for an Uility company, we are planning to specify the followings:
A surface layer of > 3000 Ohm.M and >150mm thick and 50mm Diameter shall be applied to reduce human body current

Step and Touch Voltages shall be limited to table 52 of CEC per the body of 50kg.  

Any comments would be appreciated.  


 

RE: Substation Grounding

In case of doubt, check IEEE St 80-2000 (IEEE Guide for Safety
in AC Substation Grounding)

Regards

YJO

RE: Substation Grounding

How do you plan to verify that the surfacing material is > 3000 ohm-m?  Crushed rock normally has a variety of sizes, not just 50 mm.  We normally specify crushed rock with a range of size varying from 3/8" to 1" and no fines.  We assume 3000 ohm-m resistivy, but don't specify it because it is impractical to buy crushed rock of a particular resistivity.

See IEEE Std 80 for design guidance.

RE: Substation Grounding

(OP)
Thanks. Guys,

I was in doubt about that statement. I went through IEEE 80 and It was clearer to me.  

RE: Substation Grounding

(OP)
Per CEC, a typical substation installation is designed for 0.5 s fault duration, and the entire ground surface inside
the fence is covered with 150 mm of crushed stone having a resistivity of 3000 Ω •m. Resistivity of the sample Ω •m  is provided in IEEE 80 Table 7.

 

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