×
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

underground 33,000 volts installation with water line in same trench!

underground 33,000 volts installation with water line in same trench!

underground 33,000 volts installation with water line in same trench!

(OP)
Good Evening from the LOS.
I am looking for reasons to stop a HV 33,000 volt underground power line installation with a water pipe in the same trench.

Can some one help me with the rules governing this installation.
It is being proposed by a local Electrical Contractor.
There is no inspection of the installation here.
The customer does not feel comfortable with the plan!

Advice, suggestions appreciated.

Thanks
Farang

RE: underground 33,000 volts installation with water line in same trench!

We would allow it with sufficient clearance.

For us there would be a 500mm+ grade separation (water/sewer is generally lower) and a MINIMUM of 1000m (39") horizontal separation to accommodate mechanical digging later if required.
We would insist that conduits be used for electrical, to minimize probability of having to dig it up later.
Ensure appropriate inspections take place before backfill.

Better a common trench at a known separation than two separate haphazard trenches of unknown clearances.

Our 'joint-use' trenches also make provision for natural gas pipes and telco / CATV communications conduits.
We work with a standard plan so that all agencies know where everyone else will be.

RE: underground 33,000 volts installation with water line in same trench!

By the way, you need to specify your location if you are looking for binding 'rules'.

RE: underground 33,000 volts installation with water line in same trench!

(OP)
Thanks
for your response and advice.

farang (An American in Thailand)

RE: underground 33,000 volts installation with water line in same trench!

(OP)
Hi Tinfoil,

I am in Thailand, Basically they read / look at the NEC.
If you could point me where I can find some stuff on Underground High Voltage installations.
The power company here does not do UG cabling so it is left up the the local contractor
The PEA meager the conductors and hook it up.
Thanks again for your help. The ground here is mostly sand as it is an Island.

Thanks Again
farang

RE: underground 33,000 volts installation with water line in same trench!

I expect you want to start with NFPA 70, the National Electrical Code (NEC). Section 490 looks like a place to start.

Z


RE: underground 33,000 volts installation with water line in same trench!

(OP)
Thanks guys.
I was able to show the contractor the requirements. he doesn't like them so we will see what he proposes.
Really no regulation or inspection here.
Can anyone send me a "typical" installation drawing I can show him?

Thanks
farang

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