10 kw ground array

[AES]

Hi all new to this forum. Getting ready to install ground mount system. Ground array is located 325' from main house panel. Tie in will be to supply side of service with parallel lugs in main service panel. A/C 60 amp fused disconnect next to existing meter socket.

All equipment to be installed at array.Each array has 24 Evergreen ES-A-205-fa2 solar panels. P.V. arrays will have 600 volt (60) 40 amp fused D.C. disconnects. Inverters are Fronius IG 5100 with 30 amp outputs tied to 125 amp combiner panel. Combiner panel has 60 amp breaker to A/C disconnect.

All wire is XHHW-2 copper. Wire feeding A/C disconnect 325' away is #2AWG XHHW-2.

Does #2AWG XHHW-2 copper make sense for system with this distance. Inverters were changed from sunny boy because of distance. SMA recommended 1 to 1.5% voltage drop.

[solar_geoff]

Everything sounds perfect to me so far... Just be sure to check that voltage drop carefully on that SMA calculator. For that distance and 11kw AC I would expect a larger wire guage would be needed... Maybe 2/0 or 3/0?

[AES]

Solar_Geoff, Thank you for the reply
.
Fronius is looking at voltage drop to be
,5 ohms per thousand feet as acceptable.

That is why I went with #2 XHHW-2 copper wire.

You think that is to small for distance?

[solar_geoff]

Solar_Geoff, Thank you for the reply
.
Fronius is looking at voltage drop to be
,5 ohms per thousand feet as acceptable.

That is why I went with #2 XHHW-2 copper wire.

You think that is to small for distance?

Just based on any arrays that I have done over 300 feet I don't think I have ever used less than 3/0 wire. I ran the SMA calc for 325' with a current load of 46A and that said the voltage drop is 2.5% It looks like 2/0 gives you 1.5% so that is the smallest wire size I would consider. 3/0 would be "preferrable" at 1.0% but not necessary if the extra cost is prohibitive.

[beaker127]

Wire Size Calculation

VDI = Voltage Drop Index (a reference number based on resistance of wire)
%VOLT DROP = Your choice of acceptable voltage drop (example: use 3 for 3%)
FEET = ONE-WAY wiring distance (1 meter = 3.28 feet)
Use the chart below for the AC Lines
Amps Feet % Volt Drop Voltage
VDI = 41.67 325 / 1.5 240
(Amps x Feet) / (% Volt Drop x Voltage)
13541.66667 / 360
VDI = 37.62 This number will correspond to your wire size
The number above will allow you to calculate the wire size to run between Inverters, disconnect switch and meterbase then back to main house panel