The basement watchdog arrived today; mounted it on my sump pump, and, behold, it works!
The float unit is 2 inches in diameter and 5 inches tall. It fits in my small sump bucket with room to spare. Nice - other float switches won't work in my cramped space. In the fabulous future of flying cars and robotic maids, I expect sumps to be 18, 20, or even 24 inches across. But for now, I must be content with a 12 inch diameter muckhole.
Even better: the float unit apparently runs on low voltage. This is a good thing, since it'll live around water. When it activates, I hear the guy call out, "Click" ... a sure sign that the wallwart has changed states (well, it stays in California, but perhaps it's yearning to return to its birthplace in Shanghai)
I'm happy with its timer, which keeps the pump going for 10 seconds beyond the float hitting the low end. During this time, my sump-pump slurps the last half inch out of delicious sump-syrup from the bucket.
What's wrong with it? Other pump switch connoisseurs and sump-o-philes will object to its color. It is, alas, all black. Hey - everything around a sump is black: the bucket. the hole. The mud is black. The ABS pipes. And it's the darkest corner of my cellar. Why can't someone make a float switch that shows up when I shine my flashlight there? How about a reflective or white float? Especially, a white cord, so I can see where it's twisted amidst the mud, muck, and debris?
Then, too, this is one big wallwart. A 4x3 inch lump that sticks out two inches from your wall outlet. It weighs a shade under a pound; if you often go hiking with your sump pump, you'll eventually notice this weight in your backpack.
A very useful feature would be a glowing green LED to say that, Yes, power is reaching the switch. This would save time during those all-too-wet emergencies -- is there power getting to that cellar outlet? ? ? Ideally, the light would glow green when the pump is switched off, yellow when the pump should be powered, and red when the planet Saturn is about to collide with Earth.
Sadly, this is a power vampire (even without any LED!). Using an ammeter, I measured it eating 2 watts in standby (which is what it'll do 99 percent of the time). This translates into $3/year for those of us who enjoy the flavorful electricity from Pacific Gas and Electric. So the little guy does not qualify for Energy Star (Level-V requires less than 0.5 watts in standby).
In addition, it's quite silent after the sump has been drained. I'd hoped that it would play a rousing Sousa march during the pump action, and then improvise on a few riffs by Thelonius Monk followed by a Bach cantata with a tromba da tirarsi. No such luck.