User Manual

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

Q Commercial Relay Controller (Q-RELAY-3P-NA) for Dropped Phase

and Neutral Protection

The Enphase Q Commercial Relay Q-RELAY-3P-NA monitors

line and neutral voltages and signals the coil of a contactor in

case of a dropped phase or opened neutral. The relay

controller is field selectable with support for 120/208Y and for

240V high-leg delta applications.

The Q Commercial Relay is not required for the IQ

microinverter to function, but may be required by some AHJs

and/or utilities.

You must use a “normally opened” contactor sized for the

power rating of the PV system. A 120V coil is shown in the

following schematic. For this example, a 350A continuous

rated contactor with 400A max circuit breaker rating is shown.

The contactor was sized based upon the kW rating.

Contactor shown for 65kW, 208V system:

ABB Contactor AF260-30-11-12

Sample Schematic of 208Y/120V System with Q

Commercial Relay