IQ Load Controller Additional Info

Load and Solar Circuit Control using IQ System Controller Auxiliary Contacts

Refer to the IQ System Controller QIG for installation instructions.

Note: Use 3/32inch /2 mm flathead screwdriver to work on auxiliary contact terminals.

Auxiliary contact usage

Enphase recommends using Normally Open auxiliary contacts for solar and Normally Closed auxiliary

contacts for loads. The load/solar circuit behavior represented in this document requires that a Normally

Open (NO) definite purpose external contactor be used. Enphase’s software is tailored to work with these

since these are the most readily available.

IQ System Controller’s auxiliary contacts can be used with 2 different types of external contactors:

1. Normally Open external contactor with a 24 V ac coil

2. Normally Open external contactor with a 120 V ac coil (with an interposing power relay)

Note: The definite purpose external contactor may make a humming or buzzing sound when its coil is

energized. This is normal and does not indicate issues with the equipment.

Enabling Load Control on a site

The auxiliary contacts, as described above, can be used for load shedding or PV shedding. Load

shedding can be used to shed non-essential loads on a site during a grid outage to ensure that the

essential loads are backed up for a longer time. Alternately, you may want to use the auxiliary contacts

for PV shedding to maintain the Solar-To-Storage ratio in off-grid mode on sites with IQ6, IQ7, M215 or

M250 microinverters.

In either case, you will require a general-purpose contactor, a power supply, and additional accessories to

setup a site to use the load control feature. Enphase has launched a new product, the IQ Load Controller,

which is a complete solution for using the IQ System Controller’s load control feature. Installers are

required to follow the simple and detailed instructions provided in the instructions guide with the product

to complete the wiring to integrate the IQ Load Controller with the IQ System Controller in order to setup

load control (or PV shedding) at a site.

Installers may also choose to setup a similar kit by themselves. Enphase has provided a list of

recommended contactors, control transformers and other components to setup a self-assembled kit. You

may skip to the ‘Installing a custom kit for Load/PV Shedding’ section of the document to learn more.

Using the IQ Load Controller with IQ System Controller to enable

Load control or PV shedding

Enphase’s IQ Load Controller is a complete solution for using the IQ System Controller’s load control

feature. The Enphase IQ Load Controller, when used in conjunction with the IQ System Controller,

enables control of up to two heavy loads running at 240Vac (or 4 120Vac loads) or shedding of up to two

solar circuits when operating in an off-grid mode with the Enphase energy management system.

The IQ Load Controller is a UL listed, outdoor-rated, NRTL-certified NEMA type 4X enclosure with a DIN

rail that contains two 40A contactors, a power supply, wires for control connections and other wiring

accessories. Use the IQ Load Controller for controlling heavy, split-phase loads or for solar circuit

shedding when solar power exceeds allowed solar to storage ratios. Heavy loads are those that exceed

the power or surge capabilities of your energy management system. The IQ Load Controller supports

control of 2 split-phase loads i.e., loads wired L1-L2 and running at 240V nominal AC voltage or 4 loads

running at 120V nominal AC voltage.

IMPORTANT: The Enphase IQ Load Controller is an accessory for the IQ System Controller. The IQ

System Controller is required to control loads or shed excess solar circuits using the IQ Load Controller.