I am in the process of building a smart PID temp controller to control a chest freezer to ferment beer.

I was looking for a low cost solid state relay and found an clever idea on the web.

Someone used a LED to control a AC outlet with a light sensor to switch something. I found it at my local home improvement store for $7 where the light timers are. It only switches 300W though. Not enough for my project.

I found something similar for switching outdoor lights. It will control up to 2KW and costs $10-$15.

No AC wiring is required. They are opti-isolated. Inexpensive. Longer lasting and easier to use compared to a relay.

I have not tried it yet but, I bet it will work. I will let you know.

The first thing is to determine what you need, not guess. You freezer has a motor on it (used to run the pump). What's its rating in volts and amps? This will tell you what your power requirements are, and then you can choose the proper part.

BM

An alternative would be ti use a solid state relay to drive a contactor. Something that can handle the inrush of a motor winding starting up. Inductive loads like that can really wreak havoc in an electronic circuit.