PV System Backfeeding to Utility thru padmounted transformer 1

[Omarelec]

I have a PV grid-tied system at 480/277volt tied to the service entrance switchgear. The secondary of the pad mounted transformer will be 480/277volt solidly grounded system. What configuration the transformer needs to be at the primary? what concerns I have to worry about when backfeeding?

 

[Omarelec]

I checked the inverter technical data and it says the inverter is compatible with grounded WYE

http://files.sma.de/dl/7418/STP-US_MV_Trafo-TI-en-12.pdf

 

[prc]

This is quite interesting. Can some one clarify why these two recommendations? In the above IEEE standard also ungrounded wye is recommended to PV? Difference in the type of inverters?

 

[LionelHutz]

prc - the step down transformer from the utility is powering an office building, so the secondary mus be a grounded wye connection to meet code requirements. This is dictated by the code requirements for the building service. The fact a PV system is being installed has no bearing whatsoever on this choice - the PV system has to accommodate the building service, not the other way around.

To save on installation costs for a dedicated PV service, smart inverter manufacturers will recognize there is a demand to install smaller PV systems onto or around buildings by using a breaker from the ground wye building service that already exists, and therefore build suitable inverters for that type of installation.

 

[waross]

It's also a matter of scale. kiloWatts versus megaWatts.

Bill
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"Why not the best?"
Jimmy Carter