Troubleshoot An Inoperable Microinverter - enphase M250 Installation And Operation Manual

Troubleshoot an Inoperable Microinverter

To troubleshoot an inoperable microinverter, follow the steps in the order shown.
WARNING: Risk of electric shock. Always de-energise the AC branch circuit before servicing. Never
disconnect the DC connectors under load.
CAUTION: The Enphase Microinverters are powered by DC power from the PV modules. Make sure you
disconnect the DC connections and reconnect DC power to watch for the solid green about six seconds after
connection to DC power and then six short green LED blinks two minutes after connection to DC power.
1. Make sure AC breakers and disconnects are closed.
2. Check the connection to the electricity network and verify the utility voltage and frequency
are within allowable ranges.
3. Verify that AC line voltages at all solar power circuit breakers at the AC mains and subpanels
are within the ranges shown in the following table.
4. Verify that AC line voltage at the electrical distribution board or consumer unit and at the AC
junction box for each AC branch circuit are within the ranges are shown in the following
table:
Single-phase service
L1 to neutral
5. Using an Enphase disconnect tool, disconnect the AC cable for the microinverter in question
from the Engage Cable.
6. Verify that utility power is present at the microinverter by measuring line to neutral at the
Engage Cable connector.
7. Visually check that the AC branch circuit connections (Engage Cable and AC connections)
are properly seated. Reseat if necessary. Check also for damage, such as rodent damage.
8. 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.
9. 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. See page 26 for normal LED operation.
10. 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.
11. Verify the PV module DC voltage is within the allowable range for the microinverter, as
shown in "Technical Data" on page 33 of this manual.
12. 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 isn't functioning correctly. If it stays in place, the problem is with
the microinverter. Call Enphase Customer Support for help in reading the microinverter data
and for help in obtaining a replacement microinverter, if needed.
13. 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.
14. Verify with your electricity network that line frequency is within range.
15. If the problem persists, contact Customer Support at
27
207 to 253 Vac
 2016 Enphase Energy. All rights reserved.
M-Series Microinverter Installation and Operation
Three-phase service
L1 to L2 to L3
L1, L2, L3 to neutral
enphase.com/global/support-request
360 to 440 Vac
207 to 253 Vac
.
141-00024 Rev 02b