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TECHNICAL BRIEF © 2015 Enphase Energy Inc. All rights reserved. January 20151 NEC 2014 Enphase System Code Compliance Overview This technical brief discusses new NEC 2014 requirements that apply to Enphase Microinverter Systems. It is useful for installers, electricians, and electrical inspectors or authorities having jurisdiction (AHJs) in understanding how code-compliance is handled where NEC 2014 is adopted. Main topics discussed in this document are: NEC 2014 Section 690.12 Rapid Shutdown of PV Systems on Buildings NEC 2014 Section 705.12 Point of Connection NEC 2014 Section 690.11 DC Arc-Fault Circuit Protection NEC 2014 Section 690.12 Rapid Shutdown of PV Systems on Buildings Enphase Microinverter Systems fully meet the rapid shutdown requirement without the need to install additional electrical equipment. Properly labeling the PV system power source and rapid shutdown ability is required per NEC Section 690.56 (B) and (C). Solar electric PV systems with Enphase Microinverters have one utility-interactive inverter directly underneath each solar module, converting low voltage DC to utility grid-compliant AC. When the utility grid is available and the sun is shining, each microinverter verifies that the utility grid is operating within the IEEE 1547 requirements. Only then does it export AC power into the electric service for use by loads onsite or export power to the utility grid for others to use. When the utility grid has a failure, or the PV system AC circuits are disconnected from the utility service via an AC breaker, AC disconnect, or removal of the solar or main utility service meter, the microinverters stop producing AC power in fewer than six AC cycles. Enphase Microinverters are not capable of operating as an AC voltage source. This means that without an AC utility source, Enphase Microinverters are not able to energize connected wiring and no AC voltage or current can be injected into the inverter output circuits or the grid. When the AC utility source is removed from the inverter output circuits via any means, such as an AC breaker, AC disconnect or removal of the solar or main utility service meter, this equipment performs the rapid shutdown function per 690.12. With an Enphase Microinverter System this shutdown occurs well within the 690.12 required 10 seconds, and there are no oth er conductors energized more than 1.5 m (5 ft) in length inside a building or more than 3 m (10 ft) from a PV array. Code Reference 690.12 Rapid Shutdown of PV Systems on Buildings. PV system circuits installed on or in buildings shall include a rapid shutdown function that controls specific conductors in accordance with 690.12(1) through (5) as follows. (1) Requirements for controlled conductors shall apply only to PV system conductors of more than 1.5 m (5 ft) in length inside a building, or more than 3 m (10 ft) from a PV array. (2) Controlled conductors shall be limited to not more than 30 volts and 240 volt-amperes within 10 seconds of rapid shutdown initiation. (3) Voltage and power shall be measured between any two conductors and between any conductor and ground. (4) The rapid shutdown initiation methods shall be labeled in accordance with 690.56(B). (5) Equipment that performs the rapid shutdown shall be listed and identified. 1338 N Custer St 05/01/23