enphase IQ8 Design Manual page 36

C. Cover any unused connectors on the AC cable with Enphase Sealing Caps (QD-SEAL-
10). Listen for a click as the sealing caps engage.
WARNING: Risk of electric shock. Risk of fire. Install sealing caps on all unused AC connectors,
as these connectors become live when the system is energized. Sealing caps are required for
protection against moisture ingress.
NOTE: To remove a sealing cap or AC connector, you must use the QD Disconnect Tool.
Step 5: Provide an AC connection to the branch circuit
Method A: Center-feeding the branch circuit
Enphase recommends that the total percentage of voltage rise in the AC wiring be a maximum of 2%,
with (an inclusive) less than 1% voltage rise in the QD Cable.
Although the QD Cable is optimized for minimal VRise, it is still important to calculate the total VRise for
the entire system for the farthest microinverter in the branch circuits from the point of common
coupling.
Because voltage rise is exponential, reducing the number of microinverters in the branch circuit greatly
reduces the voltage measured at the farthest microinverter in the branch. One way to minimize this
voltage rise is to center-feed the branch, that is, divide the circuit into two subbranch circuits protected
by a single OCPD. Therefore, for all installations with IQ8 Commercial Microinverters, center-feeding of
a three-phase AC supply is recommended.
Follow these installation steps for center-feeding the microinverter branch circuits:
A. All three QD Cable SKUs include center-tapping connectors after every 6 AC male QD
connectors in the QD Cable spool. The center-tap connectors are sealed with sealing caps,
and the sealing cap should be removed only when the connector is used for feeding the AC
supply to the branch.
NOTE: The center-tap connector is a three-phase male field-wireable connector. Use the
center-tap connector only for feeding in the AC Supply connection from the PV subpanel.
B. When installing the IQ8 Commercial Microinverter system using QD Cable, you may have
multiple center-tap connectors in the branch circuit. Select the center-tap connector such
that a maximum of nine IQ8 Commercial Microinverters are installed on either side of the
center-tap connector to limit voltage rise <1% in the QD Cable. Do not exceed the branch
circuit sizing mentioned in this guide.
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Figure 17: QD Cable connection
© 2023 Enphase Energy Inc. All rights reserved.
IQ8 Commercial Microinverter grid-tied PV system
November 2023
USG-00026-1.0