Step 2 - Install The Ac Branch Circuit Junction Box - Enphase Energy M215 Manuel D'installation Et D'utilisation

Step 2 – Install the AC Branch Circuit Junction Box
DANGER: Risk of Electrical Shock. Be aware that installation of this
equipment includes risk of electric shock. Do not install the AC junction
box without first removing AC power from the Enphase System.
WARNING: Only use electrical system components approved for wet locations.
WARNING: Do NOT exceed the maximum number of microinverters in an
AC branch circuit as listed on page 25 of this manual. You must protect
each microinverter AC branch circuit with a 20A maximum breaker.
a. Size the AC wire gauge to account for voltage drop. Select the correct
wire size based on the distance from the beginning of the microinverter
AC branch circuit to the breaker in the load center.
All components of system wiring must be considered, including internal
voltage drop within the length of Engage Cable. Typically, three wire
sections and several wire terminations must be quantified. There is
also some resistance associated with each circuit breaker. As all of
these resistances are in series, they add together. Since the same
current is flowing through each resistance, the total voltage drop is
total current times the total resistance. For a single-phase system, the
total resistance is equal to two times the one-way resistance. For a
three-phase system, each of the three line currents and resistances
must be calculated.
Standard guidelines for voltage drop on feeder and AC branch circuit
conductors might not be sufficient for microinverter AC branch circuits
that contain the maximum allowable microinverters. This is due to high
inherent voltage rise on the AC branch circuit.
For more information, refer to the Voltage Drop Calculations
Application Note at http://www.enphase.com/support/downloads.
b. Install an appropriate AC junction box at a suitable location on the PV
racking system (typically at the end of a row of PV modules).
c. Provide an AC connection from the junction box back to the electrical
utility connection using equipment and practices as required by local
jurisdictions.
Page 11 Copyright Enphase Energy Inc. 2011
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141-00017, Rev 01