In the evenings, sometime during the last hour of sunlight, the XW inverter starts to "hiccup", turning on/off the output. There are no (noticeable) power glitches on the grid side. It cycles on/off a few times, and then turns back on.
The Xantrex XW-6048 inverter was installed recently with existing grid-tied PV. There is an SMA and an Aurora (Power One) inverter. To get the benefit of PV when the grid goes down, both grid-tied inverters are wired into the output side of the Xantrex XW. There is roughly 6kW PV on the SMA and 3kW on the Aurora, for a total of 9kW.
The system has been working fine for a couple of months. About three or four weeks ago, I set a schedule on the XW to disable charging at night. (When the charger is off, the display shows dashes.)
The owner says the fault logs are clear. I will check the fault logs tomorrow and post back here. Any ideas what this could be?
Thanks - AJ