AC Combiner Box Installation
6. Wire Inputs from the AC Branch Circuits
The combiner comes with three 20A circuit breakers (16A continuous) to which you wire the microinverter
AC branch circuits.
a.
Use copper conductors sized per local code requirements and voltage drop/rise considerations: 12
to 6 AWG copper conductors for branch inputs.
b.
Bring in the wires from each AC branch circuit.
c.
Connect the neutral wires (white) to the neutral bus and the ground wires (green or green/yellow) to
the ground bus. Torque to 45 in-lbs (5 Nm).
d.
Connect L1 and L2 (usually one black and one red) from each AC branch circuit to the circuit
breakers.
e.
Torque to 20 in-lbs (2.4 Nm).
NOTE:
L1 and L2 should be wired as shown, with L1 and L2 alternating.
7. Install CTs for Consumption Metering (optional)
The Envoy-S inside the AC Combiner Box is pre-wired at the terminal blocks for power and production
metering connections. One solid-core current transformer (CT) is provided for revenue grade production
metering. You can install two optional split-core CTs to provide consumption metering. To do this, you must
use a protected route in conduit for the CT wires from the main load center to the Envoy-S. If you need to
extend the wires, refer to the
Enphase Envoy-S Installation and Operation Manual
at:
enphase.com/support.
DANGER!
Risk of electrocution! Do not install CTs when current is flowing in the sensed circuit.
Always install CT wires in the terminal blocks before energizing the sensed circuit.
DANGER!
Risk of electric shock. Always de-energize the load center before beginning wiring.
DANGER
: Risk of electric shock. Risk of fire. Do not wire unused terminals or terminal blocks on
the Envoy-S.
NOTE
:
Because of variance in load center design and main power feed, there may not always be
enough space to install consumption metering CTs.
NOTE
: To properly measure power and energy, CT inputs A and B must align with the respective
voltage inputs A and B. For example, make sure both CT input A and voltage input A are the
same line phases.
When installing CTs, it is important to match CT and sense voltage phases. Be sure to
consistently identify and match the two AC lines at three points: the main load center feed, the
Envoy, and the solar production circuit breaker. Wire colors (typically black and red) may not
always consistently identify Lines 1 and 2. If in doubt, use a multimeter to check.
© 2016 Enphase Energy Inc.
141-00030 Rev 02
15
