Why does the thermostat require 240volts

thermostat

Purchased smart thermostat from China still in transit, my old thermostat has two wires only from ducted gas heating unit was powered by 2-1.5 volt batteries.

The new thermostat requires a hard wire power source ,no batteries.
The connection at back of thermostat states 95-240 ac volts L and N , I gather line and neutral . See image.
My question is why do you need so many volts to power the display ?
Is it simply the fact that most households already have 110 or 240 volts (I live in Australia) supply so that's how they design them.
I just want to make sure that I don't damaged the unit by hooking up 240 volt power.

thermostat back panel

Best Answer

You kind of answered your own question: "hard wire power source, no batteries". If the thermostat requires its own power source and doesn't use batteries, then normal line and neutral household power is needed, that would be 120/204 volts. The line and neutral more than likely feed a transformer inside the unit that steps down the voltage to what the display requires.