I just had to revisit this question for I project I am working on and I'll add to this.
I still think article 225 applies but since the feeder is 'leaving' the pole I no longer think 225.31 applies
in this case.
A pole mount PV array is a Separately Derived System that supplies a feeder to another structure 690 does not modify that.
Explanation:
Per 90.3 article 690 can subtract a specific requirement of article 225 but it must do so explicitly, which it does not do.
For example recently the 2017 NEC deleted the redundant 690.3 requirement based on "proper use of code structure per 90.3".
Code:
2014 NEC 690.3 Other Articles
Wherever the requirements of other articles of this Code and
Article 690 differ, the requirements of Article 690 shall apply
and, if the system is operated in parallel with a primary source(s)
of electricity, the requirements in 705.14, 705.16, 705.32, and
705.143 shall apply.
Article 225.1 Scope states
Code:
This article covers requirements for outside branch circuits and feeders run on or between buildings, structures, or poles on the premises.."
Table 225.3 goes on to mention article 690.
690 does define the Photovoltaic Output Circuit:
Code:
Circuit conductors between the PV source circuit(s) and the inverter or dc utilization equipment.
We have a pole mounted array and we need to run a Photovoltaic Output Circuit from the pole(s) to the inverter or dc utilization equipment.
Per the definition that is both a feeder and a 'Photovoltaic Output Circuit'.
For example there are other cases where something can meet more than one code definition a common recessed can light meets the definition of luminaire and that of an outlet.
sketchy: can you find out from the AHJ what specific code section they are talking about? I am curious if it really is a local code or an interpretation of 225.31.