Troubleshoot An Inoperable Microinverter - enphase IQ8D-72-E-US Design Manual

Troubleshoot an Inoperable Microinverter

To troubleshoot an inoperable Microinverter, follow the
steps in the order shown
WARNING
Risk of electric shock. Always de-energize the AC branch circuit
before servicing. Never disconnect the DC or AC connectors under
load.
WARNING
The Enphase Microinverters are powered by DC power from the
PV modules. Make sure you disconnect the DC connections and
reconnect DC power and then watch for the solid green about six
seconds after connection to DC power.
A. Make sure AC breakers and disconnects are closed.
B. Check the connection to the utility grid and verify that
the utility voltage is within allowable ranges.
C. Verify that AC line voltages at all solar power circuit
breakers at the load center and subpanels are within
the ranges shown in the following table.
D. Verify that AC line voltage at the junction box for each
AC branch circuit is within the ranges shown in the
following table:
Service Type & Line Voltage
208VAC Three-Phase
E. Using an Enphase disconnect tool, disconnect the
AC cable for the Microinverter in question from the
Enphase QD Cable.
F. Verify that utility power is present at the Microinverter
by measuring line to line and line to ground at the
Enphase QD Cable connector.
G. Visually check that the AC branch circuit connections
(Enphase QD Cable and AC connections) are properly
© 2022 Enphase Energy Inc. All rights reserved.
183V – 229V
seated. Reseat if necessary. Check also for damage,
such as rodent damage.
H. Make sure that any upstream AC disconnects, as well
as the dedicated circuit breakers for each AC branch
circuit, are functioning properly and are closed.
I. Disconnect and re-connect the DC PV module
connectors. The status LED of each Microinverter will
light solid green a few seconds after connection to
DC power and then blink green six times to indicate
normal start-up operation about two minutes after
connecting to DC power. The LED subsequently
resumes normal operation if the grid is present.
J. Attach an ammeter clamp to one conductor of
the DC cables from the PV module to measure
Microinverter current. This will be under one amp if AC
is disconnected.
K. Verify the PV module DC voltage is within the
allowable range as mentioned in IQ8D Microinverter
specifications.
L. Swap DC leads with a known good, adjacent PV
module. If after checking Enlighten periodically (this
may take up to 30 minutes), the problem moves to the
adjacent module, this indicates that the PV module
is not functioning correctly. If it stays in place, the
problem is with the original Microinverter. Contact
Enphase Customer Support for help in reading
the Microinverter data and for help in obtaining a
replacement Microinverter, if needed.
M. Check the DC connections between the Microinverter
and the PV module. The connection may need to be
tightened or reseated. If the connection is worn or
damaged, it may need replacement.
N. Verify with your utility that line frequency is within
range.
O. If the problem persists, contact Customer Support at
enphase.com/en-us/support/contact.
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