Float Switch for Pond Fountain

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I was wondering what type of float switch you guys are using when you wire pond fountains? I've got two of them I need to wire, and I want to use the float switch to shunt trip the feeder. The switch will be installed on a 4x4 that the fountain installer mounts his control module on. My concern is the durability of the various switches I'm finding. This thing will be exposed to the elements as well as lawn mowers and the like. It would seem to me that someone must make an enclosure that would protect the switch but still allow water to enter it if the water level ever gets that high.


Senior Member
101130-1409 EST

You could use a conductive liquid level control.

This consists of an insulated probe out to the probe tip where the center conductor is exposed. Then an AC low voltage detector, less than 10 V and current limited to less than 1 MA, is connected to the probe. The probe resistance to ground is very high when no water is contacting the probe tip, and abruptly drops to a lower level when water contacts the probe tip. This closes a relay in the sensor circuit.

All of the circuitry except the probe tip can be in a clean environment.

There are high voltage circuits, but you do not want this type. There are also low voltage DC circuits. These should be avoided. DC here refers to the voltage applied to the probe.


tom baker

First Chief Moderator
Staff member
Use a stilling tube, large enought for the float switch (look at a Gems switch), 3" PVC would work, and connect at the bottom with a 1" line
to the bottom of the pond. Put a cap on top with a 1/2" vent hole. The float switch can be inside below the cap. You still tube will see the pone level and not be subject to damage.
If that won't work, then hang a 3" PVC pipe on the side of the pond.
Painting PVC dark green would be a good idea.
My goal here is to be in compliance with 682-11: Service equipment shall disconnect when the water level reaches the height of the established electrical datum plane. In both of these applications, the water level will NEVER get that high. Both ponds have over-flow runoffs that will dissipate high water before it gets to the disconnects (unless animals are lining up two by two...). My local AHJ doesn't care much for the wording of 682, so they're OK with my float switch just being at the bottom of the 4 x 4 that the fountain guy mounts his control module and time clock on.

I thought about mounting something like this inside of an enclosure:
I would think that someone would make an enclosure designed for this application. Ideally it would be non-metallic with provisions to allow high water entry while keeping bugs and other junk out (screens maybe?). Thanks for the ideas guys.


Telford, Pa
Possibly a sump pump type control could be used.
This is the type that consists of a hollow hard rubber ball with a tilt switch inside. The ball is molded to a heavy cord. The cord is anchored to a fixed point leaving the ball and about 3" of cord to move freely. When the water rises the ball will float and tilt the switch thus making the electrical connection.

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