# for pad mounted transformer secondary side, pulling wire no ground wire required?



## Switched (Dec 23, 2012)

You guys pull your own wiring from the utility owned transformer?

I can't say as to Canada, but we would not pull a ground from a utility transformer to the gear, just the hots & neutral. Your grounding begins at the gear and downstream of it.


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## triden (Jun 13, 2012)

Why are you pulling it? Typically it's the contractors responsibility to install the conduit from the transformer to the gear where Hydro will then pull the conductors. No ground typically needed as grounding is established at your service entrance.

If this were a customer owned service with a unit sub, that would be different.


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## Dash Dingo (Mar 3, 2012)

No ground 


Sent from my iPhone using Tapatalk


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## Cow (Jan 16, 2008)

We work with a few different power companies. One of them has us pull to the padmounts. 

And no, you do not need a ground wire. There are no ground wires until your main disconnect. Down here in the US, everything is bonded with the "grounded" conductor up to the service disconnect. After that you have an equipment grounding conductor.


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## Southeast Power (Jan 18, 2009)

mike883 said:


> anybody has this kind of experience about the pad mounted transformer:
> 
> here is the situation, this pad mounted transformer is in the street, its primary side is from the hydro, around 25,000V, and secondary side is going to a building's main switch gear,
> 
> ...


I asked that question and the cable splicer told me that I could install a ground wire if I was required to but, they have no place to connect it.


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## MechanicalDVR (Dec 29, 2007)

Ground your own equipment not the utilities.


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## Big John (May 23, 2010)

Suncoast Power said:


> I asked that question and the cable splicer told me that I could install a ground wire if I was required to but, they have no place to connect it.


Yep, there's a big padeye on XO and a bonding strap to a single frame ground bolt.

You can run an EGC all you want, but at the end of the day when they bond it at the transformer and then you rebond it at the service all you've done is create a poorer parallel neutral path.


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## glen1971 (Oct 10, 2012)

triden said:


> Why are you pulling it? Typically it's the contractors responsibility to install the conduit from the transformer to the gear where Hydro will then pull the conductors. No ground typically needed as grounding is established at your service entrance.
> 
> If this were a customer owned service with a unit sub, that would be different.


Hydro pulls the secondary conductors? Not on any that I've done.. 

Any padmount transformers I can remember prepping for, we installed the ground grid, rods around it, tails into the transformer, 4" PVC with long radius 90's to the location determined by the utility and all the secondary conductors. When it came to terminating, we did all the secondary terminations and since the last 20ish years have been industrial, it has all been teck, and the cable grounds have been terminated. If I remember the specs right from my time on the engineering side, there was always a ground conductor called for in the underground PVC.


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## triden (Jun 13, 2012)

glen1971 said:


> Hydro pulls the secondary conductors? Not on any that I've done..
> 
> Any padmount transformers I can remember prepping for, we installed the ground grid, rods around it, tails into the transformer, 4" PVC with long radius 90's to the location determined by the utility and all the secondary conductors. When it came to terminating, we did all the secondary terminations and since the last 20ish years have been industrial, it has all been teck, and the cable grounds have been terminated. If I remember the specs right from my time on the engineering side, there was always a ground conductor called for in the underground PVC.


Hydro here pulls them all the time. That's why their service entrance spacing requirements are crazy - 20" of width in a switchgear/mcc section to pull and terminate the secondaries. Guess every province is different...good to know. Hydro here also installs and supplies the triplex/quad for overhead services. Does Transalta do the same?


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