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20.20.027 (D) Circuits Over 150 Volts to (1) Photovoltaic Source Circuit Ground. In one- and two-family Currents. The maximum current dwellings, live parts in photovoltaic shall be the sum of parallel mod- source circuits and photovoltaic ule rated short-circuit currents output circuits over 150 volts to multiplied by 125 percent. ground shall not be accessible to other than qualified persons while (2) Photovoltaic Output Circuit energized. Currents. The maximum current shall be the sum of parallel FPN: See 110.27 for guarding of source circuit maximum currents live parts, and 210.6 for voltage as calculated in 690.8(A)(1). to ground and between conduc- tors. (3) Inverter Output Circuit Cur- rent. The maximum current shall (E) Bipolar Source and Output Cir- be the inverter continuous output cuits. For 2-wire circuits connected current rating. to bipolar systems, the maximum system voltage shall be the highest (4) Stand-Alone Inverter Input voltage between the conductors of Circuit Current. The maximum the 2-wire circuit if all of the follow- current shall be the stand-alone ing conditions apply: continuous inverter input current rating when the inverter is pro- (1) One conductor of each circuit ducing rated power at the lowest is solidly grounded. input voltage. (2) Each circuit is connected to a separate sub array. (B) Ampacity and Over current De- (3) The equipment is clearly vice Ratings. Photovoltaic system marked with a label as follows: currents shall be considered continu- Warning-Bipolar Photovoltaic ous. Array. Disconnection of neutral or grounded conductors may (1) Sizing of Conductors and over result in over voltage on array or current Devices. The circuit conduc- inverter. tors and over current devices shall be sized to carry not less than 125 per- 690.8 Circuit Sizing and Current. cent of the maximum currents as computed in 690.8(A). The rating or (A) Computation of Maximum Cir- setting of over current devices shall cuit Current. The maximum current be permitted in accordance with for the specific circuit shall be com- 240.4(B) and puted in accordance with 690.8(A)(1) through (A)(4). Exception: Circuits containing an 710-19 (Pleasanton April 2003)