[Request] Adding description for error code 36, 50 and 52 on HMT-2250

[groggy99]

Is your feature request related to a problem? Please describe.

I sporadically and irreproducibly receive error 52 in the openDTU log.

After consulting hoymiles support, the error means the following:

"Error 52 on the HMT-2250-6T microinverter indicates the DC bus voltage is too low. This can happen sporadically due to voltage drops or other temporary conditions."

Describe the solution you'd like

Can this be integrated into openDTU so that it is displayed in the log with an explanation?

Describe alternatives you've considered

No response

Additional context

No response

[groggy99]

In the meantime I also received the following undocumented errors in openDTU: 50 and 36

Statement from hoymiles support:

Error 50 on Hoymiles microinverters is related to "pre-warning of feedback over-current protection failure," typically caused by unstable grid voltage. This means the microinverter detects an abnormal current feeding back to the grid, likely due to voltage fluctuations.

Error 36 usually indicates a serial communication failure between components, such as between an indoor and outdoor unit, causing one part to stop functioning properly while others continue running. This may be caused by loose or damaged wiring, a faulty relay, blown fuse, or malfunctioning PCB.

[stefan123t]

@groggy99 thanks for your inquiry about the meaning and possible resolution steps of these three unknown errors.

We have checked v1.1.29 of the Hoymiles Installer APK, but there are now versions until v1.1.32, as well as v3.0.0 through v3.5.1 available on APK Pure: https://apkpure.com/s-miles-installer/com.hm.hemaiInstall1/versions

Maybe someone wants to check the latest versions for an updated warn_code.json ?
No new "50" / "52" in neither v1.1.32 nor v3.5.1 under assets/warn_code.json.

We have already searched for some of these unknown error codes in the warn_code.json file of the Hoymiles Installer APK in vain:

• 36 INV overvoltage or overcurrent
  36: INV overvoltage or overcurrent
  • Event ID 36 #121
  • Unknown alarm codes #590
  • on random/unpredictable bases, OpenDTU slowing down, or stop at all, working ( live view, mqtt etc )  #836
• 50 ?
  50: `` ?
  • "50_1": "AC fan fault" ?
  • according to Hoymiles support "Previous alarm of FB over-current protection failure. And also caused by unstable grid voltage."
  • [Request] Add description for error 50 #1847
• 52
  52: `` ?
  • "52_1": "220V power supply undervoltage" ?
  • "52_2": "220V power supply overvoltage" ?
  • HMS2000 Error ID 52 Unknown #2090

See here for the origin from our concise list of all yet unknown error codes as of August 2025:
#2090 (comment)