Hoymiles problem, or grid voltage too high?

[richbee]

I've noticed that my mancave pv with hoymiles inverter keeps going into error state (flashing red light).
As I don't have the hoymiles WiFi gateway thing, that's all I can see - the manual suggests it could be grid voltage too high or too low.
It does seem that this occurs when the pv output from the main sunsynk system is high - eg. Today it was showing 252V on the power meter connected to the hoymiles and 255V on the sunsynk app.

Is this unusually high for the grid voltage, or could there be hoymiles problem - if I managed to get a hoymiles gateway, are there settings to control voltage limits? The hoymiles manual suggest the limits are 180 to 270V.

Any help gratefully received

[Joeboy]

Haven't seen that here but tbh not much chance as I only check once per week at No1's place. Did you install a ketotek meter on the AC line?

I ask as other than a DC clamp meter i was guessing as to output from panels linked to Enphase inverters so went ketotek for an eyeball. Your voltages as seen don't seem too extreme. Personally I'd be checking the MC4's for arcing and moisture if you have any external MC4's on the cable runs. Not that I suspect those but hierarchal search is handy to do. First to last type of thing.

As far as I know there isn't any voltage access for adjustment on the Hoymiles software but tbh I don't have the full access i once had. Imagine tier 1 being full registered access? I now have network access problems although my log in still works . Tier 3 maybe? I have to go through toolkit button to see data. Sorry long way round to saying 'can't help'.

[Joeboy]

Although on reading the original post again I'd maybe get a handle on the frequency of the hoymiles error state and maybe knock off the sunsynk inverter and retest in case they are fighting each other in a '1 potato 2 potato' scenario.

If you get no clear result there I'd be looking at monitoring hoymiles output on the AC side. Just to get a handle on generation.

[Joeboy]

Reading this again (again). A poor connection at one of the MC4's would give this behavior. The unit would keep rebooting as the DC kicks in and out.

[richbee]

Thanks Joe,
So, yes, I do have the ketotek meter on the ac side, that's how I noticed the output was at 0. So I went outside to check the inverter, which was showing a slow flashing red light.
The inverter manual suggests several possible causes for the slow flashing light, and they are all to do with improper grid conditions, such as voltage too high or low.
I'm not sure if an mc4 problem could lead through into a grid problem - but good to know that is one place to check for any future problems.
Checking back over the last week, it looks like it might have happened on the 22nd too. The hoymiles re-connects itself once the fault goes away - so I'm looking for a dip in output which is not connected to clouds going overhead.
On the 22nd,the sunsynk also showed high voltage >255V at about the same time as the hoymiles drop out.
It seems to tie in with the battery being full and the inverter exporting, but not always - so not sure what affects the grid voltage?
I'm in the countryside and on the end of a grid connection line - there are only 4 properties served by overground wires and we are at the end - could that affect the voltage, the rate the exported energy is dissipated?

[Joeboy]

The red light flashing. If you power off the AC side, does it mimic what you are seeing in day to day? I'm hoping for an intermittent connection somewhere. Fingers crossed.

Might be worth continuing your dno on the supply quality?

[Countrypaul]

The previous place I lived was supplied by overhead wires across the fields, there were just 3 properties, our houseand next doors and the farm. When certain things were operating at the farm it could make our lighs noticeably dim. At one point we had a problem with a blown board in a washing machine, the repair engineer checked the mains voltage and it was above the maximum (253V ?). as a result we contacted the electricity supplier and they had n engineer out the sme day who was going to install some monitoring, but measured our voltage and next doors and nect day there was a team of engineers out changing things(the tappings I believe) on the pole mounted transformer. Light bulbs lasted much longer after that.

It might be worth checking your mains voltage with no pv/batteries in use, if it is high get your supplier to investigate.

[Joeboy]

I went over to No1's place and switched off the AC. Sure enough red light flashing away. Took a good few minutes for it to self test and start outputting again. Would it be a simple process to run an extension reel to the Hoymiles and try again on a known AC line?

Just trying to prove if its on the property or outwith.

[richbee]

The previous place I lived was supplied by overhead wires across the fields, there were just 3 properties, our houseand next doors and the farm. When certain things were operating at the farm it could make our lighs noticeably dim. At one point we had a problem with a blown board in a washing machine, the repair engineer checked the mains voltage and it was above the maximum (253V ?). as a result we contacted the electricity supplier and they had n engineer out the sme day who was going to install some monitoring, but measured our voltage and next doors and nect day there was a team of engineers out changing things(the tappings I believe) on the pole mounted transformer. Light bulbs lasted much longer after that.

It might be worth checking your mains voltage with no pv/batteries in use, if it is high get your supplier to investigate.

What counts as high voltage? Normal seems to be more like 240-245, with the 255 peaks with full battery & sun shining.
I thought they were trying to gradually bring it down to nearer 200 in the long run, and 220-230 at the moment

[richbee]

I went over to No1's place and switched off the AC. Sure enough red light flashing away. Took a good few minutes for it to self test and start outputting again. Would it be a simple process to run an extension reel to the Hoymiles and try again on a known AC line?

Just trying to prove if its on the property or outwith.

That's good that yours does the same - but yes, it seems to take a few minutes to reset itself & start working.
I think I should try it with the sunsynk turned off on a sunny day & see what it does.
It's mostly nice here today and it has dropped out a couple of times - I thought it might be ok as there have been multiple washing loads, dishwasher, soup cooking etc after our return from Norway.
If I look at the sunsynk voltage output it does seem to reach 254 or above when the hoymiles drops out.