Temporary Generator to Replace a POCO XFMR

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Harold-eng

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Tampa, FL
I have a project where I am removing one transformer and installing a new one in a different location to accommodate a building that is getting larger. The transformer serves 4 meter centers which are not associated with the building expansion. Due to the routing of the primary and project phasing, we cannot get the new transformer up and running before the old transformer must be removed.

It was suggested that we use a portable generator temporarily to re-feed the existing meter centers. However, the service laterals (120Y/208) from the POCO transformer do not contain and equipment grounding conductor and they are long (between 150 and 450' each at 600A). Thus, If we use a generator to take the place of the POCO transformer, I interpret that the generator definitely WILL be a separately derived system and that we must make the system N/G bond at the generator per 250.20(D) and 250.30(1).

I want to know if anyone believes that it is permitted to NOT run an equipment grounding conductor in the meter center service laterals (which will temporarily become "feeders" from the generator) and make the system bond at the meter center.

Thanks
 
I do not know that the situation you are describing can be defined as an SDS. Can we assume the utility service did not include an EGC. Best thing to do is get ahold of AHJ, if in the city of Tampa call Nelson Montgomery or one of his guys. A temp situation will sometimes get you some leeway.
 
barbeer said:
hopefully you do not violate 300.3(b).:smile:
Click to expand...

I guess you're right - putting the ground in a spare conduit would violate 300.3. Only alternative I can think of is just installing the generator close to the service using temp conductors, fenced enclosure, etc
 
It is actually city of Dunedin (someone's looking at my profile):wink:.

The metercenters are on a dock, thus the reason for the long distances and no ability to serve with a generator close by.

Correct, the utility service laterals do not contain and EGC.

I too believe that running the required EGC separate from the phase conductors would be a violation of 300.3(B), so I did not consider or discuss as an option. Additionally, since we are on a dock, it would not be easy to install a conduit for a temp situation, unless on top of the dock, which just gets less and less desirable.

This generator would be the prime source of power for 1-2 months and people live on their boats at this marina. A safe and reliable grounding systems is my top priority.

Geeze...It is in RGC under the dock from the point which it meets up with the seawall. That may work...Gotta check more code.
 
Use the provisions of 250.32(B)(2) for the the generator installation. The neutral is bonded at both the generator and the service disconnects and you do not need an EGC between the generator and the service equipment.
Don
 
don_resqcapt19 said:
Use the provisions of 250.32(B)(2) for the the generator installation. The neutral is bonded at both the generator and the service disconnects and you do not need an EGC between the generator and the service equipment.
Don
Click to expand...

That is what I was trying to get at.......not even needing a EGC.

Whenever you post it tells us you are in Tampa!:D Actually, Rich Hittle is the main man (electrically) down there. Is it the Marina downtown or on the causeway?
 
This is for the Marina on Dunedin causway. I think Rich is the electrical inspector, correct?

I have been speaking with Rick Johnson regarding my issues. I believe he does the plan reviews and Rich does the inspections. He has been very kind and helpful.

I have since moved to working in Clearwater since joining the forum. I should change my location:)
 
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