I have a bathroom and wash machine in my basement. The water & sewage drains into a what looks like a 55 gal tank, it is then pumped up into the main sewer line from the home to the street main line. Should my sump pump be completely under water before the float tells it to turn on? Won't it short out?
As far as the water level it should not go any higher than the height of the lowest drain in the tank. In other words you should always be able to see the pipes that drain into the tank. I'm not a big fan of the free floating switches, if the pump is not placed correctly in the tank the switch can get stuck between the pump and the tank causing the pump to continuously run or not run at all. In my opinion the switches that have a float within a cage are better, the cage keeps floating things from hanging the float up. I have my switch adjusted so the pump doesn't kick on until the water level is just below the lowest drain. This way the pump doesn't run as often. Some switches have a timer and if you have them set too low it will pump out all the water and then continue to run dry which is not good for the pump and wastes electricity. As far as short out I suppose if the float gets stuck and it runs dry for too long it can overheat and short out. Being submerged helps keep it cool, running dry for 10 - 20 seconds will not overheat it.