float switch not working

gregapex Registered Users Posts: 9 ✭✭

I have a float switch.  https://www.amazon.com/dp/B07PXFPPMM?psc=1&ref=ppx_yo2ov_dt_b_product_details.  I am running it 260’ to my well pump with 18/3 sensor wire.  It's not turning off the pump when tank is full.  What am I doing wrong and/or what device do I need to install to increase the voltage over that distance, if that is in fact the problem.

thank you




  • Graham Parkinson
    Graham Parkinson Registered Users Posts: 160 ✭✭✭
    According to Amazon this is a 4 to 20 mA device, meaning that it changes it's resistance to adjust current flow to signal to compatible 4 to 20 mA equipment (i.e. it would work something like allowing 4mA when empty and 20 mA when full or vice versa).  You may have it hooked up as a simple float switch (ie zero resistance closed to infinite resistance open) which may explain why it's not working.

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