Hoymiles problem, or grid voltage too high?

[richbee]

I don't know anything about hoymiles, so I don't know if you have access to its settings. If you can set it to a UK spec it ought to keep working up to 264v ish. That would be the optimum solution.

You can get voltage optimisers that reduce the supply voltage to your house, though I'm not convinced they would save you any money as they claim. This one seems to be an autotransformer that reduces the voltage by 7.5% (~18v):-

https://www.cef.co.uk/catalogue/product ... ation-unit

If I were considering this solution myself I'd probably cobble up something similar, but just for the hoymiles, not the whole house, which would be much cheaper:

E.g. if you were just going slightly over 253v with an inverter that could output up to 15A a.c., then knocking off 10v would suffice, so I would look for something like a 150va 10v: 230v, (I.e. 15A at 10v output) transformer. Connect the 10v winding in series with the 230v winding to make a 230/240v autotransformer. Check you've got the polarity right by connecting 230v to the 230v 'tapping', and the output from the ends should be 10v more, not 10v less. Connect the '240v' to the grid side and the hoymiles to the 230v tapping, and the hoymiles should see grid -10v, approximately.

If the output of the hoymiles is approaching 253v the output from the autotransformer will be near 264v though, which is still OK, but it is the reason I suggest a 10v transformer: a 20v transformer would get the apparent voltage at the hoymiles nearer to 230v at grid=250v, but then the hoymiles wouldn't cut out until the grid reached 253+20v, which would be inadvisable.

One of the problems with the hoymiles systems is that we can't currently access the settings, as the WiFi gateway is not available to register in the uk.

[Fueltheburn]

Was looking into mine just now, the grid voltage is about 235v at night. I wonder what it's like midday in the sun.
Pretty sure I have seen 250v on the other inverter last year but this was the local transformer was replaced. Seems to have been lower ever since.



Whilst I was digging around, I found something I hadn't noticed before. Decided to max out this setting as it was left blank. Will keep an eye on the performance after this change

[pudding]

So which Hoymiles do you have where you can log in and see those details? Do you have an extra unit in order to do so? And, is there any setting anywhere to increase a high voltage protection/cutout value?

I'm considering buying a seperate DTU unit in order to log in to my Hoymiles inverter if I can work out how to do it for a decent price and the voltage limits can be tweaked.

[Fueltheburn]

The HMS series has a built in WiFi that the unit outputs.
So long as the unit is connected to the grid, panels producing power and LED is illuminated on the unit you should be able to connect it.
Once the sun goes down, the unit stops transmitting.
You have to be within range of the WiFi to pick it up.
I have my geo-location on the phone ON, connect to the installer app on my usual WiFi and then choose the plant I have setup. At this point I have to connect to the Hoymiles own WiFi, once this is done I can see the last 30 days of daily production and the current days power being produced.

I have an installers account. It does not allow me to adjust the grid voltage parameters.
Which means it is unlikely to be available in the standard user account version but I haven't looked. I will have a look tomorrow evening.

[pudding]

The HMS I have doesn't have Wifi built in, so I've bought the DTU-Lite stick in order to take a look at the settings, couldn't resist! Didnt break the bank at less than £30 from Amazon.

Set it up last night, via the mobile app. Had installer account set up for me by OffGridTech in Germany where I bought the inverter from. All registered and set up fine. There's not a huge amount of settings available in the app, but if you go to the web portal you can do more, including looking at the grid profile. When I inspected this on the inverter there were no settings coming back from the inverter, so I uploaded a G99 UK profile they had on the web portal, so now I have this:




which seems like fairly sensible and similar settings to my other inverters, so hopefully now I won't get the Hoymiles tripping out when the sun pops out from behind the clouds and peaks the voltage briefly, we'll see! Weather is going to be spiky today with passing clouds and showers so might find out the answer today if this is the fix or not.

Edit: That profile can also be edited and saved as a different one and re-uploaded too, so seems like it'll be fairly flexible and tweak-able

[Joeboy]

Well played Sir! I look forward to reading on the results

[richbee]

The HMS I have doesn't have Wifi built in, so I've bought the DTU-Lite stick in order to take a look at the settings, couldn't resist! Didnt break the bank at less than £30 from Amazon.

Set it up last night, via the mobile app. Had installer account set up for me by OffGridTech in Germany where I bought the inverter from. All registered and set up fine. There's not a huge amount of settings available in the app, but if you go to the web portal you can do more, including looking at the grid profile. When I inspected this on the inverter there were no settings coming back from the inverter, so I uploaded a G99 UK profile they had on the web portal, so now I have this:




which seems like fairly sensible and similar settings to my other inverters, so hopefully now I won't get the Hoymiles tripping out when the sun pops out from behind the clouds and peaks the voltage briefly, we'll see! Weather is going to be spiky today with passing clouds and showers so might find out the answer today if this is the fix or not.

Edit: That profile can also be edited and saved as a different one and re-uploaded too, so seems like it'll be fairly flexible and tweak-able

Sounds promising

[pudding]

2 days now with no issues and shutdowns. Yesterday was cloudy/sunny spells with spikes on the grid voltage that I would've expected to have shut it down previously, so it seems to have done the trick. Will reply again if it trips out and it turns out not to have worked out.