Liquid Water Level Sensor,DC0-110V Stainless Steel Liquid Water Level Sensor Switch 1/2Npt Male Thread Water Level Sensor for Water,Fuel, Water Towers

Although we purchased this quite some time ago and installed it then, a few months later it did not operate as a switch any longer. I understand it is a switch, either normally open or normally closed, so I am not quite sure how the voltage quotes would be applicable with exceptions. Here it says DC0-110. It does not require power therefore the lead in and out maybe they mean that path to withstand only Direct Current? We have it on one line, a positive DC line in line to our pump to cut it off when tank is full. We ordered normally closed to keep that path going either from or to, our motor. I watched it move the float to full position therefore "open" the positive DC line, but it does not do so. When it did on the bench. Now out again, and there is no change at all on continuity when there was testing on our bench three months ago. I would never return this at all, just fix it or buy another one. Presently we are going to cut it open to see why.

I'm not an engineer, just a guy trying to make a water level indicator for his christmas tree stand. This seems too simple to not work, but I also am not sure how to hook it up exactly. Is it static open or static closed, is it polarized, is there a minimum voltage for it to work? Idk, but maybe I'm just a doofus. I feel like a spec sheet or some instructions would help. Also, it's annoying that I had to buy my own flange nut, because this didn't come with one.