The thermostat is dead in my strange¹ fridge with no replacement parts. I posted about the mystery component before.
There is a metal plate that appears to sandwich a single small loop of refrigerant (guessing!). Mounted attached to the backside is a coil with a ground and two wires marked to handle 220v. One of the leads connects to the LOAD wire on house mains and the other to the (now broken) thermostat.
I can only imagine that it’s a heating element for defrosting (as suggested). But I struggle a bit with that theory because I’m surprised the fridge would ever get cold enough to justify defrosting.
Anyway, I wired the mystery coil directly to mains and left it for 10 min or so. The temp of the metal plate did not feel any different. Is that expected? Metal is naturally cold at room temp and that did not change.
I would like to understand it because I cannabalised a simpler t-stat from another fridge. The t-stat has no connector for whatever the mystery component is.. it’s just a switch that connects two wires. I don’t know if I should just omit the mystery component, or if I should wire it in series with the new t-stat, or keep it attached to the old broken t-stat and wire that in parallel to the new t-stat.
¹ I say strange because there is no freezer-fridge vent. So the fridge is independently cooled.
In that case, I suppose I should wire it in series with the “new” (harvested) thermostat that will be the replacement. Then both the t-stat and the mystery component would be able to open the circuit.
I suppose I could test it.. if I warm up the plate with a heat gun, I could see if the mystery component acts like a thermal breaker.