Paco Solar
Member, NABCEP Installer
- Location
- Southeastern PA
- Occupation
- Solar Engineer (PE)
Hello Folks,
Scenario: Supply-side PV interconnection ("IX") inside a Utility CT cabinet (load-side of CT's....permitted by this Utility).
Focus of question: The conductor segment from the fused PV Disconnect to the above IX point (about 5 LF)
For my typical designs, I will downsize the Neutral in the previous (upstream) wire segments (i.e. from inverters to AC-disco), as permitted by Code and by Inverter Mftr (Enphase).
My practice has been, for this last segment, to terminate the EGC in the AC-Disco (where it is bonded to the N), and only continue the (fully sized) Neutral (and phase conductors) on to the supply side IX point. (often in the Service Gear/MCB...)
My understanding is we make the Neutral in this segment Full-size, since the Code allows it to be reduced, but not less than the size of the EGC, and since there is no EGC in this segment, there is no "minimum" N size, so it can't be reduced....but that seems like an argument from silence.
Can anyone point to Code sections that would more formally require the above return to "full-size" for this portion of the Circuit, or is it just good practice?
thank you
Scenario: Supply-side PV interconnection ("IX") inside a Utility CT cabinet (load-side of CT's....permitted by this Utility).
Focus of question: The conductor segment from the fused PV Disconnect to the above IX point (about 5 LF)
For my typical designs, I will downsize the Neutral in the previous (upstream) wire segments (i.e. from inverters to AC-disco), as permitted by Code and by Inverter Mftr (Enphase).
My practice has been, for this last segment, to terminate the EGC in the AC-Disco (where it is bonded to the N), and only continue the (fully sized) Neutral (and phase conductors) on to the supply side IX point. (often in the Service Gear/MCB...)
My understanding is we make the Neutral in this segment Full-size, since the Code allows it to be reduced, but not less than the size of the EGC, and since there is no EGC in this segment, there is no "minimum" N size, so it can't be reduced....but that seems like an argument from silence.
Can anyone point to Code sections that would more formally require the above return to "full-size" for this portion of the Circuit, or is it just good practice?
thank you