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Troubleshoot an Inoperable Microinverter
To troubleshoot an inoperable microinverter, follow the steps in the order shown.
WARNING: Always de-energize the AC branch circuit before servicing. Never disconnect
the DC connectors under load. Disconnect DC connections first, then disconnect the AC
connections.
WARNING: The AC and DC connectors on the cabling are rated as a disconnect only
when used with an Enphase Microinverter.
WARNING: 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 utility grid and verify that the utility voltage are within allowable
ranges shown in the Technical Data section on page 29 of this manual.
3. Verify that AC line voltage at all solar power circuit breakers at the load center and subpanels
is within the ranges are shown in the following table.
4. Verify that AC line voltage at the junction box for each AC branch circuit are within the ranges
are shown in the following table:
240 Volt AC, Split Phase
L1 to L2
L1, L2 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 line and 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
21 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 shown in the Technical Data
section on page 29 of this manual.
22
211 to 264 VAC
106 to 132 VAC
L1, L2, L3 to neutral
2013 Enphase Energy Inc.
M250 Installation and Operation
208 Volt AC, Three Phase
L1 to L2 to L3
183 to 229 VAC
106 to 132 VAC
141-00022 Rev 01
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