Troubleshooting an Enphase System
2014 Enphase Energy Inc.
August 2014
22
Microinverters are not detected, or, power line communication level is low or poor
If the Envoy LCD level indicator displays 2 or fewer bars,
, or you may be seeing “
Microinverter Failed to
Report” events.
1. The Envoy may be plugged into an AC outlet that is too far from the electrical load center. Relocate it
to an outlet physically closer to the load center.
2. Is there an unbroken Neutral line from the load center to the solar array branch circuit? This is
required for system communications.
3. Is another device causing interference?
If the Envoy is not detecting the Microinverters in the array(s), or if the event
log frequently lists
Microinverter Failed to Report
events, then either the power line communication signal strength
is weaker than required, or there is interference on the line from a device at the site.
Unplug any other device that may be sharing the outlet with the Envoy. Use another outlet for the
unplugged device.
The following devices
may
interfere with power line communications:
power strips and surge protectors on the same circuit
UPS (Uninterruptible Power Supply) / battery backup units on the same circuit
dimmer switches
home automation/security devices that use power line communication
touch lamps
battery chargers (cell phone and laptop chargers)
AC adapters (laptop power cord)
heavy rotating motors (e.g., fans, refrigerators, freezers, water pumps)
workshop equipment (e.g., drill press, table saw, wood routers, planers)
CFLs (Compact fluorescent lights) with failed ballasts anywhere in the home
electronic pest deterrents
GFI outlets
some brands of arc-fault protected outlets (arc-fault breaker)
Determine the source of the interfering load by isolating the Enphase signal from other systems.
The Enphase system transmits at 144kHz, and adequately filters X10 and other signals. but not
all other systems adequately filter the Enphase signal. To best isolate the signal:
Install a PV subpanel to land all the solar branch circuits.
Install a dedicated outlet for the Envoy (and power line communication bridges, if needed) off
the subpanel.
Filter the phase conductors running from the subpanel back to the load center. Ferrite toroids
are an effective, simple filtering mechanism. Refer to
http://en.wikipedia.org/wiki/Toroidal_inductors_and_transformers for more information. Here
is the link to specific model required:
http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=Epcos+B64290L0
082X087
If this subpanel is remote from the router, you may need power line communication bridges to
span the gap from the Envoy back to the site’s router. However, remember that these bridges
do not help or hinder the power line communication signal between the Envoy and the
microinverters.
If the signal path for the bridges is impeded by the use of the subpanel, you can use a
wireless Ethernet bridge instead.
