Relay help. ATO

[Snaz]

Originally Posted by mike31154

Instead of making things more complex with a relay, have you considered making it simpler instead? I have a similar ATO with an air pump pressurizing a container but use a mechanical furnace humidifier float switch to limit the fill level rather than an electrical float switch to turn a pump on and off when the level drops. I use a regular, small aquarium air pump plugged into a timer which cycles on for a few minutes every hour. This keeps the top off container sufficiently pressurized to keep up with evaporation, while the mechanical float switch keeps the level from rising above the set/desired level. Once you've got the timings dialed in to keep up with evap, it works like a charm and if the pump happens to run a little longer, no harm done, the float valve prevents any likelihood of overfilling. Less electrical around water = more warm & fuzzy safe feeling.

I'm intrigued. How big is the float switch? I have to mount it in a rear chamber that is 3.5" x 3.5",