IQ8AC/IQ8HC Installation and Operation Manual
21 © 2023 Enphase Energy Inc. All rights reserved. June 2023
USM-00005-2.0
6. Troubleshooting
Follow all the safety measures described in this manual. Competent personnel can use the
following troubleshooting steps if the PV system does not operate correctly.
WARNING: Risk of electric shock. Do not attempt to repair the Enphase microinverter; it contains
no user-serviceable parts. If it fails, contact Enphase customer support to obtain an RMA (return
merchandise authorization) number and start the replacement process.
Status LED indications and error reporting
The following section describes LED indications.
LED operation
Flashing green
Normal operation. AC grid function is normal and there is communication with the
IQ Gateway
The AC grid is normal but there is no communication with the IQ Gateway
The AC grid is either not present or not within the specification
Solid red
There is an active “DC Resistance Low - Power Off” condition. To reset, refer to the
IQ Gateway Installation and Operation Manual at: https://enphase.com/en-
au/installers/resources/documentation. If problem persists, measure resistance
between PV+ to EARTH and then PV- to EARTH on the PV module and then inverter.
Anything less than ~7 kΩ will trigger the “DC Resistance Low - Power Off”
condition. Usually, the value is in MΩ on inverter or PV module. Swap out faulty PV
The status LED on each microinverter lights green about six seconds after DC power is applied. It
remains lit solid for two minutes, followed by six green flashes. After that, red blinks indicate that no grid
is present if the system is not yet energized.
Any short red blinks after DC power is first applied to the microinverter indicate a failure during
microinverter startup.
DC Resistance Low – Power Off condition
For all IQ8 Series Microinverters, a solid red status LED when DC power has been cycled indicates the
microinverter has detected a DC Resistance Low – Power Off event. The LED will remain red, and the
fault will continue to be reported by the gateway until the error has been cleared.
An insulation resistance (IR) sensor in the microinverter measures the resistance between the positive
and negative PV inputs to the ground. If either resistance drops below a threshold of 7 kΩ, the
microinverter stops power production and raises this condition. This may indicate defective module
insulation, defective wiring or connectors, moisture ingress, or a similar problem. Although the cause
may be temporary, this microinverter condition persists until the sensor is manually reset.
An IQ Gateway is required to clear this condition. The condition clears on operator command unless its
cause is still present.
If a microinverter registers a “DC Resistance Low - Power Off” condition, you can attempt to clear this
condition. If the condition does not clear after you perform the following procedure, contact Enphase
Energy customer support at https://enphase.com/contact/support.
To Next Page
Loading...
Need help?
General