underground 33,000 volts installation with water line in same trench! 1

[Farang50]

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

 

[tinfoil]

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.

 

[tinfoil]

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

 

[Farang50]

Thanks
for your response and advice.

farang (An American in Thailand)

 

[Farang50]

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

 

[zappedagain]

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

Z

 

[PersonalProfile]

This may be of interest:

http://www.eng-tips.com/viewthread.cfm?qid=383176

Regards,
Lyle

 

[Farang50]

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