Shelly 1PM gets hot

Got two Shelly 1PM, flashed with tasmota, calibrated on 60W bulb, everything works.

Week ago attached one to air conditioner which uses 1500W (7A):

when off shelly temperature is 50-60c at 25c room temp

when on shelly temperature gets to 75c after an hour and then heating cycle ends so shelly cools

seems bit high but as long as it gets to 75c max I’m ok with it.

Now attached one to water heater which uses 2600W (12A):

when off shelly temperature is 50-60c at 25c room temp

when on shelly temperature gets to 90c after 20 minutes and turns off by itself.

I’m using them only for monitoring power consumption not for controlling devices.

Wired them both according to shelly instruction like this:

What could it be source heating problem? 12A should be ok on 16A switch

Zitat von Seven of Nine

Don't worry, 75 degree Celsius is the internal temperature (MCU) which is absolutely ok ..

Shelly1PM automatically turns off if a critical temperature is reached (which is IIRC around 95 degree celsius)

this is the self protection mentioned above.. the issue is probably related to the place where the Shelly is installed.. a closed box? then there is no air circulation which increases the temperature over the time..

Maybe you can install inside a bigger box or with some distance to other devices, which may affect the temperature?

Yes it's in very tight and closed box and there is no possibility for better place

These devices supposed to be in such places I think, and still it's only 12A from 16A

Maybe tasmota firmware has something to do with it, later I'll reflash them and try with original firmware

From your signature you have tons of Shellys, did you try one of them under load of more than 10A for long period of time, at least an hour?