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Conductor, Conduit, and OCPD Sizing Validation 1. Maximum System DC Voltage Test 1.1. Solar Edge inverter w/24 Canadian Solar CS3N-390MS (390W)s Array Properties Array Type Distributed MPPT System Inverter Array System Description Solar Edge inverter w/24 Canadian Solar CS3N-390MS (390W)s Module CS3N-390MS (390W) Highest number of modules in series in a PV Source Circuit 1 Design Low Temp.1.7°C Module voc 44.1V Temp. Coefficient voc -0.115V/C CEC Code Calculations A. Maximum Voltage of PV Source Circuit 46.78V see CEC 690.7(A) CEC 690.7(A) requires that if the PV module manufacturer provides a temperature coefficient of open-circuit voltage, it must be used to calculate the PV array's maximum system voltage. It includes an information note recommending the use of the ASHRAE 'Extreme Annual Mean Minimum Design Dry Bulb Temperature' as the design low temperature. Using these values, the module Voc (44.1V) will increase to 46.78V at the design low temperature (1.7°C). (1.7°C - 25°C) X -0.115V/C + 44.1V = 46.78V The module Voc at the design low temperature is 46.78V. 46.78V X 1 = 46.78V B. Maximum Voltage of DC-DC Converter Source Circuit 400V see CEC 690.7(B)(2) All PV circuits have a voltage that does not exceed 600V. This system's DC-DC Converter Source Circuits are fed by Solar Edge S440 DC-to-DC converter optimization devices. Each device is connected to a single CS3N-390MS (390W) PV module. The voltage of this circuit is regulated by the inverter at a constant 400V. CEC Code Validation Tests 1. PV Source Circuit maximum Voc must not exceed 600V 46.78V < 600V = true PASS 2.DC-DC Converter Source Circuit voltage must not exceed 600V 400V < 600V = true PASS 2. Wire, Conduit, and OCPD Code Compliance Validation 2.1. #1: DC Circuit Circuit: DC Optimizer to Transition Box Circuit Section Properties Conductor 10 AWG PV Wire, Copper Equipment Ground Conductor (EGC) 6 AWG Bare, Copper OCPD(s) N/A Raceway/Cable Free Air Lowest Terminal Temperature Rating 90°C Maximum Wire Temperature 55°C Power Source Description DC-to-DC converter source circuit consisting of 12 Solar Edge S440 optimizers. Power Source Current 15A Voltage 400V CEC Code Calculations A. Continuous Current 15A see CEC 690.8(A)(1)(d) The continuous current of this DC-DC converter source circuit is equal to the rated maximum output current of the optimizer. Rated Max. Output Current of optimizer is 15A B. Ampacity of Conductor 55A see CEC Table 310.15(B)(17) Ampacity (30°C) for a copper conductor with 90°C insulation in free air is 55A. C. Derated Ampacity of Conductor 42A see CEC Table 310.15(B)(3)(c), CEC Table 310.15(B)(3)(a), and CEC Article 100 The temperature factor for 90°C insulation at 55°C is 0.76. The fill factor for conductors in free air is 1. The ampacity derated for Conditions of Use is the product of the conductor ampacity (55A) multiplied by the temperature factor (0.76) and by the fill factor (1). 55A X 0.76 X 1 = 41.8A rounded to 42A D. Max Current for Terminal Temp. Rating 40A see CEC 110.14(C) The lowest temperature rating for this conductor at any termination is 90°C. Using the method specified in CEC 110.14(C), the maximum current permitted to ensure that the device terminal temperature does not exceed its 90°C rating would be the amount referenced in the 90°C column in CEC Table 310.15(B)(16), which is 40A. E. Minimum Required EGC Size 12 AWG see CEC Table 250.122 and CEC 690.45 The smallest EGC size allowed is 12 AWG for OCPD rating 20A according to Table 250.122. According to CEC 690.45, it is not necessary to increase the size of the PV array's EGC when conductors are oversized for voltage drop considerations. CEC Code Validation Tests 1. Derated Ampacity must be greater than or equal to the Continuous Current (CEC Article 100) 42A >= 15A = true PASS 2. Conductor Ampacity must be at least 125% of Continuous Current (CEC 215.2(A)(1)) 55A > 15A x 1.25 = true PASS 3.Max current for terminal must be at least 125% of the Continuous Current. (CEC 110.14(C)) 40A >= 15A X 1.25 = true PASS 4.EGC must meet code requirements for minimum size (CEC Table 250.122) 6 AWG >= 12 AWG = true PASS 5. EGC must meet code requirements for physical protection (CEC 250.120(C)) 6 AWG >= 6 AWG = true PASS 2332 N Spurgeon St05/30/23