I'm currently gathering the materials for a 8.4kW solar system mounted on south facing house and (attached) garage roofs, with asphalt shingles. 3 strings in 11-11-8 with:
Trina 280w panels
UniRac SolarMount racking
SMA Sunny Boy SB7.7-1SP-US-40 inverter
The panels will all be mounted in landscape with vertical railing on the house rafters and horizontal on the garage. Roof slopes are 45degrees.
Shading: 2 dormors on the house roof and also the garage roof is 2ft lower than the house roof. I'm going with SMA TS4-R-O optimizers (Tigo) on the 16 shaded panels.
We are on 2008 NEC (PA).
It would be easier to run PVwire down to the inverter, as I was planning on buying 3 x 50ft MC4 10awg PVwire cables, but I spec'd this in case:
DC side: 6awg solid bare ground wire connecting to 5 groups of panels then into entry junction box, 6 x 10awg PVwire with crimped on MC4 connectors to the same entry junction box on the side of the house above the garage roof. 6 x 8awg THWN-2 in Flexible Metal Conduit through attic then into the garage down to inverter (which should have an integrated DC disconnect).
AC side: 8-3 Romex to a MidNite Solar AC Surge Protector then down to the Main Service Breaker Box (200amp busbar with 200amp main breaker) in the house basement. 40amp breaker located at the bottom of the box (opposite side of main).
Although digitally locked off when main is off:
2008 NEC 705.22 Disconnect Device (6) "Capable of being locked in the open (off) position"
So I guess I'll buy a breaker lockout for the only case of work being done on the inverter side with the main on.
The plan is to drill up through the center of the rafters from the attic. Geocel 2300 for sealant.
UniRac Rails: I have to cut a bit of the 8 208inch rails and cut a 240inch rail into 4 rails. For a every other rail in each, I'll drill a 7/32inch hole into the rail for the Ilsco grounding lug.
I still have to source which perminant labels for code to purchase.
Let me know what you think. Any input is appreciated.
Edit: Added updated setup
New image in my next reply.
Old image for reference: Roof (Vertical) 2 171015220604.png
Trina 280w panels
UniRac SolarMount racking
SMA Sunny Boy SB7.7-1SP-US-40 inverter
The panels will all be mounted in landscape with vertical railing on the house rafters and horizontal on the garage. Roof slopes are 45degrees.
Shading: 2 dormors on the house roof and also the garage roof is 2ft lower than the house roof. I'm going with SMA TS4-R-O optimizers (Tigo) on the 16 shaded panels.
We are on 2008 NEC (PA).
It would be easier to run PVwire down to the inverter, as I was planning on buying 3 x 50ft MC4 10awg PVwire cables, but I spec'd this in case:
DC side: 6awg solid bare ground wire connecting to 5 groups of panels then into entry junction box, 6 x 10awg PVwire with crimped on MC4 connectors to the same entry junction box on the side of the house above the garage roof. 6 x 8awg THWN-2 in Flexible Metal Conduit through attic then into the garage down to inverter (which should have an integrated DC disconnect).
AC side: 8-3 Romex to a MidNite Solar AC Surge Protector then down to the Main Service Breaker Box (200amp busbar with 200amp main breaker) in the house basement. 40amp breaker located at the bottom of the box (opposite side of main).
Although digitally locked off when main is off:
2008 NEC 705.22 Disconnect Device (6) "Capable of being locked in the open (off) position"
So I guess I'll buy a breaker lockout for the only case of work being done on the inverter side with the main on.
The plan is to drill up through the center of the rafters from the attic. Geocel 2300 for sealant.
UniRac Rails: I have to cut a bit of the 8 208inch rails and cut a 240inch rail into 4 rails. For a every other rail in each, I'll drill a 7/32inch hole into the rail for the Ilsco grounding lug.
I still have to source which perminant labels for code to purchase.
Let me know what you think. Any input is appreciated.
Edit: Added updated setup
New image in my next reply.
Old image for reference: Roof (Vertical) 2 171015220604.png
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