Phase Balancing For Iq8D Microinverter System; Figure 69: Qd Cable Configuration For Qd-12-42-63 (15.1 Ft) - enphase IQ8D-72-E-US Design Manual

L1 - Black
L2 - Red
L3 - Blue
NS - White
P1 P2 P3 P4 P1 P2 P3 P4
C1 - #1 C2 - #2

Phase Balancing for IQ8D Microinverter System

This section explains how phase balancing can be achieved in IQ8D Microinverter system with different system
configurations. If the site layout does not allow the installer to meet all required design considerations, then calculate
expected phase Power imbalance due to the additional number of Microinverters on each phase. Please refer to local
AHJs rules for acceptable phase imbalance across the system –
This section details out -
1. Impact of phase rotating QD Cable on IQ8D system
phase balancing.
2. Impact of varying Branch circuit size on IQ8D system
phase balancing.
Conclusion - For multiple system sizes and installation scenarios, following are the impact on phase balancing for
IQ8D System.
• If the number of Microinverters in the IQ8D Microinverter system are in multiples of 3 with individual branch circuits of
any size (max. 9 micros), then IQ8D system shall have balanced configuration across all 3 phases if no connectors in
QD Cable are skipped during installation.
• If the number of Microinverters in the IQ8D Microinverter system are not in multiples of 3, then number of micros
across each phase (L1-L2, L2-L3 & L3-L1) may differ by maximum of 1 micro per phase if no connectors in QD Cable
are skipped during installation. Please refer to local AHJs rules on acceptable Phase Imbalance across the system.
• When connectors in QD Cable are left unused in a three-phase system, it creates a phase imbalance for the system
with each phase (L1-L2, L2-L3, L3-L1) having different number of Microinverters. If multiple connectors in QD Cable
are skipped over multiple branch circuits, the imbalance shall multiply.
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P1 P2 P3 P4 P1 P2 P3 P4 P1 P2 P3 P4
Center Tap
C3 - #3 C1 - #4
Connector
(Not for MI) #5
P1 P2 P3 P4
Link Connector
(AC Female)
3 Phase Female
Field wireables

Figure 69: QD Cable Configuration for QD-12-42-63 (15.1 ft)

P1 P2 P3 P4 P1 P2 P3 P4 P1 P2 P3 P4
C2 - #6 C3 - #7 C1 - #8
3. Impact of number of Microinverters in system on IQ8D
system phase balancing.
4. Impact of skipped connectors on IQ8D system phase
balancing.
Sequence continues through the Cable
for QD-12-42-63
P1 P2 P3 P4 P1 P2 P3 P4 P1 P2 P3 P4
Center Tap
C2 - #9 C3 - #10
Connector
(Not for MI) #5
P1 P2 P3 P4
Link Connector
(AC Female)
3 Phase Female
Field wireables
IQ8D-DG-MKT-00397-02-EN-US-2022-06-10
P1 P2 P3 P4
C2 - #12
83