Level Ac Displacer Type Level Switches are designed for top mounting and are particularly suited for the level control of liquids under conditions of turbulence or agitation. Their operating principle produces relatively wide switching differentials.
Changes in operating differentials and actuating levels may be made in the field by repositioning the displacers along the stainless steel cable. Porcelain displacers are standard on the SL-400 series. Standard cable length is 10 ft.
NOTE - Explosion-proof and Vapor-proof housings are U/L and CSA Approved as float-operated motor control unit for use in hazardous locations.
Model SL-400 LevelAc level switches use 'heavier-than-liquid" displacers which sink below the surface of the liquid under control. Spring suspension balances the normal displacer weight and as the liquid level rises around the displacer, it is buoyed up by a force equal to the weight of the liquid displaced. The apparent weight loss allows the spring to move the internal armature into the externally mounted switch's magnetic field to produce switch operation.
Mercury Switching Station - A glass capsule containing the mercury and switch contacts is mounted on a pivoted arm. A magnetic armature moves up and down inside a non-magnetic sealing tube following movement of the float caused by changing liquid level in the float chamber. As the armature enters the field of the Alnico V magnet mounted on the opposite end of the pivoted arm, magnetic attraction causes the magnet to approach the sealing tube and tilt the mercury capsule to make or break an electrical circuit.
Snap Switching Stations: - An Alnico 8 magnet surrounds the sealing tube and concentrates powerful magnetic force in a small space. Movement of the armature into the magnetic field shunts attraction away from the external pole pieces which allows the pivoted actuator plate to "snap" the SPDT switch making the circuit "COM" to "NC" and breaking "COM" to "NO".
|Volts||AC Amps*||AC H.P.||AC Pilot Duty||DC Amps*||DC H.P.|
*Anti-vibration switch rating