Back feeding through transformers

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sketchy

sketchy

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Do the same rules apply to the primary side of a transformer as the secondary when back feeding PV? Say you have a 208 volt panel that is back fed by a PV system. This panel is fed from a 30 kva transformer which is fed by a 50 amp breaker in some 480 volt switch gear. Does the 50 amp breaker need to be on the opposite end of the bus? Do you need to label the 480 volt side the same as you would the 208?
 
sketchy said:
Do the same rules apply to the primary side of a transformer as the secondary when back feeding PV? Say you have a 208 volt panel that is back fed by a PV system. This panel is fed from a 30 kva transformer which is fed by a 50 amp breaker in some 480 volt switch gear.

Does the 50 amp breaker need to be on the opposite end of the bus?

Do you need to label the 480 volt side the same as you would the 208?
Click to expand...

If you want to use the 120% provision then the breaker needs to be on the end.

Not sure what labels you are referring to.
 
I was talking about the "inverter output connection do not relocate this device" label.
 
sketchy said:
Do the same rules apply to the primary side of a transformer as the secondary when back feeding PV? Say you have a 208 volt panel that is back fed by a PV system. This panel is fed from a 30 kva transformer which is fed by a 50 amp breaker in some 480 volt switch gear. Does the 50 amp breaker need to be on the opposite end of the bus? Do you need to label the 480 volt side the same as you would the 208?
Click to expand...
If the panel has no OCPD then you have a line side connection are are only limited by the size of the service. If the panel has OCPD then you must comply with 705.12(D)(2)(3) section (a), (b), (c), or (d). The 120% rule with the backfed breaker opposite the OCPD on the bus is section (b).
 
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