enphase IQ8D-72-E-US Design Manual page 91

Figure 75: Phase balancing using QD Cable phase rotation when using QD Cable QD-12-20-135 (7.9
Conclusion
• As shown in the above example, when cable connectors are left unused on 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 cable connectors are skipped over multiple branch circuits, the imbalance can multiply.
Installation Guidelines:
• Minimize the number of unused QD Cable connectors - You can avoid the skipping of the QD Cable connectors with
the use of 3 Phase Field wireable (QD-CONN-10F and QD-CONN-10M) connectors along with Raw QD Cable to extend
the cable drop length.
• If the installation requires few connectors to be skipped during installations, it is recommended to make sure that
equal number of micros connected to C1(L1-L2), C2(L2-L3) and C3(L3-L1) type connectors.
• If the number of Micros connected to C1, C2 and C3 type of connectors is not same, please refer to local AHJs rules
for acceptable phase imbalance across the system.
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ft Cable), branch circuit of varied sizes and few skipped connectors
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