IQ Load Controller Additional Info

Load and Solar Circuit Control using IQ System Controller Auxiliary Contacts
31 © 2021 Enphase Energy Inc. All rights reserved. December 16, 2021
Step
Symptom
Possible cause
Solution
If you suspect miswiring or if the
auxiliary contact is not working,
check the continuity across the
auxiliary contact terminals. When
the system is on-grid, both NC
and NO auxiliary contacts will be
in closed position.
4
Contactor is under
powered. Diagnosed
by measuring AC
voltage on contactor
coil.
Contactor produces loud
buzzing and there is no
voltage on load side (not
closed.) A quiet 60 Hz hum is
expected, a loud buzzing
indicates that the contactor
may not be closing due to
insufficient transformer size or
excessive voltage drop
Confirm definite purpose
contactor coil voltage is 24V.
Increase wire size if a single
contactor. Change to a single
contactor per control transformer.
5
Contactor does not
open when expected.
NC 1/ NC 2 Aux contact is not
configured. Unplug the
terminal block to ensure that
the contactor opens.
Ensure Auxiliary contacts are
configured and provisioned in
Enphase Installer App
Table 12: Troubleshooting