Delta Cogeneration tied to Wye Service from power company

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MRG

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Hello all,
I mostly read the posts on this forum and have only posted a couple of times. I'd appreciate any input to my question below.

I am involved with an engineered project where a biogas fired genterator will be co-generating 480 volts ungrounded Delta back to a main distribution center that is powered by a 480volt wye transformer supplied by street power. There will be no grounded or grounding conductor carrried between one source and the other. The main reason for this configuratoin is because there are three existing conductors run underground between the street service and the location of the co-gen. The distance is about 2000' underground and the cost of running new UG conductors would make the RIO poor.
This is for co-generation only. When street power goes dead, the generator will shut down within 5 cycles of initial power failure. Anybody see any code issues surrounding this connection?

Thanks,
MRG
 
Obviously just an opinion, but it seems to me the installation is a violation of Art 705.14
 
Thanks Larry,

I think I didn't get correctly follow your response at first glance. The load does require a neutral. However, we will be using the nuetral from the Wye supply only. Theory is, when the power from the wye supply goes down, the delta supply will also go dead within 5 cycles. Also, if one of the delta conductors should go to ground, the wye supply breaker will be the one that trips thus shutting down the cogen within 5 cycles.
 
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