Advantages Of Center Feeding Qd Cable Ac Branch Circuit; Figure 9: Center Tap Connector; Table 12 : Ac Branch Circuit Supply Recommendation - enphase IQ8D-72-E-US Design Manual

Since voltage rise is non-linear, 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-
Cable SKU (Pitch)
QD-12-10-150 (4.6 ft)
QD-12-20-135 (7.9 ft)
QD-12-42-63 (15.1 ft)
* Center feeding possible only with junction box

Advantages of center Feeding QD Cable AC Branch Circuit

Enphase recommends that the total percentage of voltage
rise in the AC wiring be maximum of 2%, with (an inclusive)
less than 1% voltage rise in the QD Cable. A fully populated
IQ8D branch circuit has 9 Microinverters on AC Branch
circuit. If center-fed, there will be four Microinverters on
one sub-branch circuit and five on the other sub-branch
circuit.
The center-tapping AC male connector is marked "Center tap" and "Do Not Connect Microinverter".
Do not use the center tap connectors for connecting to the Microinverter.
The center-tapping connector in the QD cable is covered with sealing cap. Do not remove pre-installed sealing caps
if the center tap connector is not used for center feeding using Center Tap Adapter Cable (QD-LINKFW-10).
© 2022 Enphase Energy Inc. All rights reserved.
VRise for last
PV Module
Microinverter
Orientation
with end feeding
Portrait 0.56%
Landscape 0.95%
Landscape Ballast 1.83%
** Center feeding with center tap connector in QD Cable or junction box

Table 12 : AC Branch Circuit Supply recommendation

Figure 9: Center Tap Connector

feed the branch, that is, divide the circuit into two sub-
branch circuits protected by a single OCPD.
Recommended
Vrise Connection: End / Center Feeding
<1% in QD Cable
<1% in QD Cable
<1% in QD Cable
For IQ8D Microinverter system installations with QD-12-
42-63, the voltage rise in QD Cable is >1% for the farthest
Microinverter in branch circuit. Hence for all installations
with QD-12-42-63 cable, center feeding of three phase AC
supply is recommended. The QD-12-42-63 cable includes
a center-tapping connector in an alternating pattern after
sequences four and five connectors as shown in Figure 10.
The center-tapping connector follows similar pattern of
sequence throughout the QD Cable.
IQ8D-DG-MKT-00397-02-EN-US-2022-06-10
Recommended AC Branch
End / Center Feeding*
End / Center Feeding*
center Feeding**
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