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D. Electrical Calculations <br />1. PV Circuit current <br />PV circuit nominal current <br />Continuous current adjustment factor <br />PV circuit continuous current rating <br />8.1 amps <br />125% <br />10.125 amps <br />2013 CEC Article 705.60(B)) <br />2. Overcurrent protection device rating <br />PV circuit continuous current rating <br />Next standard size fuse/breaker to protect conductors <br />10.125 amps <br />15 amp breaker <br />Use 15 amp AC rated fuse or breaker <br />3. Conductor conditions ofuse adjustment (conductor ampacity derate) <br />a. Temperature adder <br />Average high temperature 40.9 °C (105.62 °F) <br />Conduit is installed 1" above the roof surface Add 22 °C to ambient <br />Adjusted maximum ambient temperature 62.9 °C (145.22°F) <br />2013 CEC Table 310.15(B)(2)(a) <br />b. PV Circuit current adjustment for new ambient temperature <br />Derate factor for 62.9 °C (145.22°ID 58% <br />Adjusted PV circuit continuous current 17.4 amps <br />2013 CEC Table 310.16 (bottom of table) <br />c. PV Circuit current adjustment for conduit fill <br />Number of current-carrying conductors <br />Conduit fill derate factor <br />Final Adjusted PV circuit continuous current <br />3 conductors <br />100% <br />17.4 amps <br />2013 CEC Table 310.15(B)(2)(a) <br />Total derated ampacity for PV circuit 17.4 amps <br />Conductors (tag2 on 1-line) must be rated for a minimum of 17.4 amps <br />THWN-2 (90 °C) #16AWG conductor is rated for 18 amps (Use #16AWG or larger) <br />4. Voltage drop (keep below 3°/0 total) <br />2 parts: <br />1. Voltage drop across longest PV circuit micro-inverters (from modules to j-box) <br />2. Voltage drop across AC conductors (from j-box to point o f interconnection) <br />2013 CEC Table 310.16 <br />1. Mirco-inverter voltage drop: <br />The largest number of micro-inverters in a row in the entire array is 9 inCircuit 1. According to <br />manufacturer's specifications this equals a voltage drop of 0.39 %. <br />0.39% <br />2. AC conductor voltage drop: <br />= Ix Rx D (+240 x 100 to convert to percent) <br />= (Nominal current of largest circuit) x (Resistance of #16AWG copper) x (Total wire run) <br />= (Circuit 1 nominal current is 8.1 amps) x (0.00508£2) x (943 + (240 volts) x (100)1.61% <br />Total system voltage drop:20/0 <br />vivint solar