Single Stage Liquid Level Switches are designed to shut down machinery or turn on warning devices when the liquid supply fails or recedes to a predetermined level.  They can be wired to flash a warning light, sound a howler, shut down a machine, or signal a computer.  This is especially helpful in unattended automated plants.  The units can be used with large bearings, gear cases, transformers, circuit breakers, oil tanks, and cutting oil reservoirs on screw machines, along with many other applications.  

This stainless steel liquid level switch is designed for internal use on open or pressure tanks.  The stainless steel float and switch should be aligned at the height where low liquid level is a concern.  The low level actuation point is measured from the end opposite of the wires.  The low level actuation point for water is 1 1/4”, oil is 1 3/8”, and spirits is 1 7/16”. 

When the liquid in the reservoir recedes to the low level, a magnet carried inside of the stainless steel float actuates a reed switch within the central pipe.  The normally closed design means the contacts open with the descending liquid level.

This unit tolerates up to 200 PSI and temperatures up to 220° F. The overall height of the switch is 3 3/8" (discluding the length of the wire).

For best results use the switch with Oil Rite relay A3154.  If the switch is used without the suggested Oil-Rite relay, be sure to keep the switch load within the resistive load rating, as follows:

For additional installation, maintenance, and electrical information, reference the “Liquid Level Switches” document located on the right hand side of this page.