Dc Resistance Low - Power Off Fault; Other Faults; Troubleshoot An Inoperable Microinverter - enphase C250 Installation And Operation Manual

DC Resistance Low – Power Off Fault
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 Envoy until the error has been cleared.
An Envoy is required to clear this condition. The condition usually clears with operator intervention unless
conditions causing the event have not been remedied or if the failure is permanent.
Follow the instructions in the Envoy Communications Gateway Installation and Operation Manual at
http://www.enphase.com/support
support at
enphase.com/en-us/support/contact

Other Faults

All other faults are reported to the Envoy. Refer to the Envoy Communications Gateway Installation and
Operation Manual at http://www.enphase.com/support

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 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.
1. Make sure AC breakers and disconnects are closed.
2. Check the connection to the utility grid and verify that the utility voltage is within allowable
ranges.
3. 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.
4. Verify that AC line voltage at the junction box for each AC branch circuit is within the ranges
shown in the following table:
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.
28
to clear this condition. Or, for assistance, contact Enphase customer
.
Three Phase at Each Branch Circuit
L1 to L2 to L3
L1, L2, L3 to neutral
 2015 Enphase Energy Inc. All rights reserved.
C250 System Installation and Operation
for troubleshooting procedures.
limit to 429 VAC
limit to 248 VAC
141-00025 Rev 03