User Manual

Planning for a Three-Phase IQ Microinverter System – North America

Sealing Caps

Unused Q Cable connectors must be sealed with a watertight sealing cap (Q-SEAL).

Seal each unused connector on the Q Aggregator with a male sealing cap. Also, use male sealing caps to

temporarily seal any exposed IQ Microinverter connectors not connected to the Q Cable to protect against

moisture or water damage at the exposed connector during construction.

Q Terminator

Install a terminator on any cut end of Q Cable that is not terminated with a Field Wireable Q Connector.

Commercial IQ System Design

The new IQ system provides the lowest installed cost of any three-phase microinverter system. The IQ

system can be interconnected to a three-phase, 208Y/120V utility system or to a 240 high-leg delta (with

stinger) without any transformers! Other utility voltages are supported with the installation of a transformer.

Each IQ Envoy can support up to 600 Enphase Microinverters communicating over power line

communication, and an unlimited number of Envoys may be installed on a system, allowing for limitless

scalability. For systems larger than 600 microinverters, or for systems with multiple IQ Envoys on a common

transformer, some filtering must be provided for electrical isolation between each IQ Envoy communication

domain. The communication domain is the fundamental building block in an Enphase Microinverter system,

and the maximum number of microinverters per communication domain is 600. For more on wiring IQ

Envoys for three-phase applications see “Wiring the IQ Envoy for Three-Phase Applications” on page 2.

Three-phase, 208Y/120V System Design

Designing a three-phase, 208Y/120V system is straight-forward and simple. Design the system much like

you would design a residential system, using two-pole circuit breakers. The two-pole circuit breakers are

installed in a three-phase, 208Y/120V panel board. Take care to balance the number of microinverters across

the three phases.

A neutral is not required to the roof with the microinverter branch circuits, and the IQ Microinverters do not

have a neutral connection. However, a 120V line to neutral connection is required to power the IQ Envoy.

Therefore, it makes sense to install a neutral conductor at the solar subpanel and to power the Envoy from a

Male connector on Q Cable

Female Sealing Cap (Q-SEAL)

Male Sealing Cap

(Q-BA-CAP)

Q Terminator on each cut end of

Q Cable