TLDR: I have a 120V 1/4 HP general purpose motor with pump head attached (with female threaded connections for input and output). Could I keep this pump/motor above ground and run PVC from the pump head input to the bottom of a sump tank?
I have drainage issues in my unfinished, dirt-floor basement – it is so damp down there to the point that the red clay soil is ALWAYS damp unless we have >1-month of no rain. I have been converting this space to a workshop (drill press, mitre saw, dust collection, mini lathe, hydraulic press, and storage of wood/metal materials).
I'm thinking of installing a sump pump as part of a solution/prevention. I am also looking at the grading/slope around the house, drainage from roof, etc., but this question is specific to the sump pump. I have seen the pedestal vs. submersed sump pumps, but I have never seen a completely external sump pump and motor. I have several 120V motors with attached pump heads that I picked up extremely cheaply. The motors are 1/4 HP and they're rated at 18GPM (gallons-per-minute) I'd rather put one of these to use if I can rather than purchase a new pump. I am considering keeping the motor and pump above ground, with a section of piping running down to the bottom of the sump collection tank. Does this sound feasible? I can't seem to find anyone else doing this and was wondering why. I usually find people hacking almost anything into a solution.
The pumps I have are basically a lower-duty variation of this:
Best Answer
Pumps where the pump mechanism (the impeller) is above the water line must be primed. So there is water in the impeller and no big airbubbles in the inlet pipe. If this is not the case then you can damage the pump.
You'll need a non-return valve at the inlet to prime it but if it leaks then you cannot keep the pump primed for any extended amount of time.
You could create a prime-on-demand mechanism where when you need to pump first a few gallons of water is used to prime the pump after which the pump can activate.
The cheaper solution is to run a shaft from the motor to the impeller (like a pedestal pump) or submerge the entire motor/pump. Only after taking precautions for waterproofing the wiring and ensuring adequate cooling.