For discussion only ... ~ 1kW

[Information Technology and Solar Solutions]

There was a question: For those of you whom are looking to implement
at least 2 solar energy systems of at least 1kW, consider as one a
pole mounted array 6 modules and 6 inverters with micro-inverters. If
on a pole in a back yard area, but remember typically at least 70% of
the area in the backyard must remain free.

With regards to single phase, the backfed breaker calculated also in
accordance with NEC 240.6 Standard Ampere Ratings at the point of
connection NEC 690.64(B) would be, if an 'M190-72' The reason a
string inverter with 6 modules would not be an options, is the start
voltage of the inverter would be higher than the combination, based on
both V(oc) and V(mp). If a 190W / 240V = 0.79A * 6 inverters
would be 4.75A with a minimum * 1.25 -> standard size back breaker of
15A. Also, the backfed breaker "shall be positioned at the opposite
(load) end the input feeder location or main circuit location.",
suggest 2008 NEC 690.64(B)(7) as an FPN to the California Electrical
Code 2007 - NEC 2005 although only about 6A as calculated. And
because of 2008 NEC 690.31 "system voltages greater than 30 volts are
installed in readily accessible" As a result, would suggest as Article
100 Accessible, Readily (Readily Accessible) would be "ready access is
requisite to climb over or remove obstacles or to resort to portable
ladders, and so forth." would suggest a height of the pole by an
elevation of 2.5 m (8 ft) and secure and support in accordance with
NEC® 338.10(4)(b) Uses Permitted. Exterior Installations "supported in
accordance with NEC® 334.30 for Securing and Supporting." "support
shall be supported and secured by staples, cable ties, straps,
hangers, or similar fittings designed and installed so as not to
damage the cable, at intervals not exceeding 1.4 m (41/2 ft) and
within 300 mm (12 in.) of every outlet box."

The number distance from the array to pole mount would determine if 6
modules may be used based on the AC Voltage drop which would be ~< 1%
For 6 modules would depending on the size of the conductor, for
instance, would be ~> 200 feet from the structure if using 10AWG. If
one plans on trenching would be in accordance to NEC 300.5. Although
there may be setback requirements, suggest a "clear brush area of ten
feet (10')" Also internet connectivity for monitoring.

If inverter not readily accessible AC, then 2008 NEC 690.14
Additional Provisions. (D) Utility-Interactive Inverters Mounted in
Not-Readily-Accessible Locations. (C) (2) Marking. "Each photovoltaic
system disconnecting means shall be permanently marked to identify it
as a photovoltaic system disconnect." (C) (1) Location. "The
photovoltaic disconnecting means shall be installed at a readily
accessible location either on the outside of a building or structure
or inside nearest the point of entrance of the system conductors.
" (D) (3) "The alternating-current output conductors from the inverter
and an additional alternating-current disconnecting means for the
inverter shall comply with 690.14(C)(1)."(C) (5) "A photovoltaic
disconnecting means shall not be required at the photovoltaic module
or array location." For micro-inverters, regards to disconnects -
since the DC connector would be the DC disconnect therefore use NEC
690.18.

As for macro-or traditional inverters,

If method not readily accessible DC, then 2008 690.31 Methods
Permitted (E) Direct-Current Photovoltaic Source and Output Circuits
Inside a Building. "Where direct-current photovoltaic source or output
circuits of a utility-interactive inverter from a building-integrated
or other photovoltaic system are run inside a building or structure,
they shall be contained in metal raceways, or metal enclosures, from
the point of penetration of the surface of the building or structure
to the first readily accessible disconnecting means. The disconnecting
means shall comply with 690.14(A) through (D)."

Beside reviewing the type of soil, for a pole mount, there would be
depth requirements. For pole mounts, the options would be side of
pole, or top of pole mounts. Suggest a top of pole mount for the 6
(six) modules. In addition, there would b other rebates and
incentives with systems > 1kW. When trenching, consider the
requirements of NEC 300.5

Thanks for the opportunity to present, in creating the questions for
the presented quiz, hopefully helpful the emphasis to keep it a
simple.

With regards the intriguing 3 phase presentation and discussion,
provokes the question with regards to electric meter's digital signal
processor (DSP) which appear to have features and may measure the
fundamental only or fundamental plus harmonics as an option for the
recorder quantity of kWh. It seems "depending on this factor and the
nature of the load, the energy registration of the meter can be either
larger or smaller. Fundamental only may yield a larger watthour
registration because the harmonics can have negative effect on total
accumulation." ?

Looking forward to further discussion.