Switching is effected in this unit through transforming, by means of an eccentric cam at fulcrum, the vertical motion of the float with level change to the considerably reduced movement of a horizontal switch plunger which is arranged to operate a SPDT/SPCO microswitch. Isolation of the switch mechanism from liquid monitored is effectively maintained by the use of a seal on the horizontal switch plunger. 

This type of level switch can therefore be used on tanks under pressure or vacuum, being suitable for pressures up to 3.5 bar (spherical float only) and liquid temperatures up to 100° C. 

The switch can be installed either via a 27 mm clearance hole, utilising the joint washer and back nut supplied, and the float re-attached to the rod. Where there is no access to the tank interior, the cylindrical float with 2”/50 mm flange version enables installation without removing and re-attaching the float.

This design is suitable for mounting through a tank top or cover and utilises a free float principle. The float is allowed to travel unrestricted up or down the rod in response to level change between the limits set by the upper and lower adjustable rod collars which are fixed in position at preselected points. 

Both types LF35A (for high or low alarms) and type LF35B (with a latching mechanism suitable for pump control) can be installed in non-pressurised tanks and sumps with liquid temperatures up to 100° C. They can be fitted with a cover plate or flange to ease installation. The float rod can be supplied between 260 mm and 2,000 mm to suit application, the required length must be stated upon ordering. 

Each float switch is tested and adjusted individually to suit float/float rod fitted. Wetted parts are 316 stainless steel with nitrile seal.