Breaker size design question?

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mnlara

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Oakland,California
Sample system 1: (30) Canadian Solar 285w Solar panel, 3 string of 10 panel with (1) SMA America SB9000 (240v) inverter.. The inverter max output current is 37.5 Amp. What circuit breaker at the service panel should I use?
Sample System 2: (27) Canadian Solar 285w Solar panel, 3 string of 9 panel with (1) SMA America SB8000 (240v) inverter.. The inverter max output current is 30.4 Amp. What circuit breaker at the service panel should I use?
 
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Smart $

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Location
Ohio
mnlara said:
Sample system 1: (30) Canadian Solar 285w Solar panel, 3 string of 10 panel with (1) SMA America SB9000 (240v) inverter.. The inverter max output current is 37.5 Amp. What circuit breaker at the service panel should I use?
Sample System 2: (27) Canadian Solar 285w Solar panel, 3 string of 9 panel with (1) SMA America SB8000 (240v) inverter.. The inverter max output current is 30.4 Amp. What circuit breaker at the service panel should I use?
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50A and 40A respectively. Next standard sizes up from 125% times the max inverter output rating [690.8(B)(1)].
 
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Smart $

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mnlara said:
That's correct. Thanks, I'm learning a lot from you guys. As for the wiring for ground coming out of the array junction box should I use #8 wire (or #10) THHN/THWN-2?
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Lacking info to say with certainty. See 690.45.
 
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Zee

Senior Member
Location
CA
mnlara,
1. minor correction on output amps = 32 A for sma 8000. Doesn't change size of brkr though. Still 2p40A.
2. if, by "ground", you mean your DC EGC (not your DC GEC) then make it equal to your largest hot wire in same conduit.
 
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