According to the instructions, one must first connect the panels to the Hoymiles micro inverter, i.e., DC first and then connect the AC cable from the micro inverter to the grid socket.
if I follow these instructions, the micro-inverter only flashes red and does not supply AC to grid. In order to resolve this, I must first connect the AC and then connect the panels; the micro-inverter flashes green and then works.
Does anybody know how to rectify the cabling sequence?
Best regards.
You have only to wait a few minutes, then the red light switch to green.
It is the NA protection 
Many thanks!
I’ve repeated the operation several times allowing the micro-inverter to stabilise, but the red light persists and no output to AC is generated.
It seems to get stuck in a loop when powered from DC and appears to be start-up logic related, i.e., when synchronising /referencing the grid.
Best regards
In normal operation, latest at night there is no DC power any more, but AC is still available. So latest after the first night this should be working again.
From this behaviour, it does not make sense to connect DC first… But anyway, I have some Hoymiles inverter running, and never had a problem with this indeed.
Many thanks, this makes sense however I need to allow for a situation whereby AC is disconnected and subsequently restored.
I’m wondering if this is a firmware related problem as an exact same model is behaving correctly?
Best regards
What type of Hoymiles inverter is showing this behaviour? Is it maybe an older version?
I have the HMS-800W-2T and a HMT-1800-6T running without such a “problem”.
The models are the same namely HMS-800W-2T
What is the PV voltage going into the micro? It won’t accept a PV startup voltage above 60V even though the datasheet says it can handle up to 65V.
This is pushing the bounds a bit for a Victron forum.
It does seem better asked on that manufacturers forum.
Pls check (defective) grid code parameters in your Hoymiles.
I have a HM-600 with recovery frequency of 502Hz instead of 50.2Hz. This device needs a loss of DC to power cycle and synchronize to the grid.
I nearly got mad while configuring frequency shifting on my MP2s for recovery while grid loss and after SOC goes below 100%. (Recovery).
My other HMS with proper grid code work as expected.
That said, it’s now up to Hoymiles forum
Thank you all very much for all your help on this; I’ll see if I can find a suitable forum!