IQ8MC/IQ8AC/IQ8HC Microinverters Installation and Operation Manual
26 © 2023 Enphase Energy Inc. All rights reserved. October 2023
USM-00008-1.0
Troubleshooting
Follow all the safety measures described in this manual. Qualified 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 Support to obtain a return merchandise authorization
(RMA) number and start the replacement process.
Status LED indications and error reporting
The following section describes LED indications.
LED operation
LED color Indicates
Flashing green
Normal operation. AC grid function is normal, and there is communication with the IQ
Gateway.
Flashing orange The AC grid is normal, but there is no communication with the IQ Gateway.
Flashing red 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, see “DC
Resistance Low – Power Off Condition” below. Refer to the IQ Gateway Installation and
Operation Manual at: https://enphase.com/installers/resources/documentation. If the
problem persists, measure the resistance between PV+ to EARTH and then PV- to
EARTH on the PV module and then inverter. Any value less than ~7 kΩ will trigger the
“DC Resistance Low, Power Off” condition. Usually, the value is in MΩ on the inverter or
PV module. Swap out the faulty PV module or microinverter.
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 remains red, and the fault
continues 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 Support
.
Follow the steps below to send a clear message to the microinverter. Note that the condition will not clear after the
sensor reset if the cause of the failure is still present. If the condition persists, contact your installer.
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