4
46-624 Series 3 Liquid Level Switches ASME B31.1 Construction
Swing in
position
Switch
Return spring
Enclosing tube
(non-magnetic)
Attraction
sleeve
Magnet
HL
1.0
Introduction
The MAGNETROL Series 3 level switches are float oper-
ated units suitable for use on clean liquid applications for
level alarm, pump control and safety shutdown functions.
Units are designed, fabricated and certified to compliance
with ASME B31.1 specifications.
1.1 Principle of Operation
The design of MAGNETROL float-operated level switches
is based upon the principle that a magnetic field will pene-
trate non-magnetic materials such as 316 stainless steel.
The float moves a magnetic attraction sleeve within a non-
magnetic enclosing tube and actuates a switch mechanism.
The enclosing tube provides a pressure seal to the chamber
and therefore to the process.
1.2 Operating Cycle
As the liquid level rises in the chamber (refer to
Figure 1
),
the float moves the magnetic attraction sleeve up within
the enclosing tube and into the field of the switch mecha-
nism magnet. As a result, the magnet is drawn in tightly
to the enclosing tube causing the switch to trip, “making”
or “breaking” an electrical circuit. As the liquid level falls,
the float drops and moves the attraction sleeve out of the
magnetic field, releasing the switch at a predetermined
“low level” (refer to
Figure 2
). The tension spring ensures
the return of the switch in a snap action.
2.0
Installation
2.1
Unpacking
Unpack the instrument carefully. Inspect all units for
damage. Report any concealed damage to carrier within
24 hours. Check the contents of the packing slip and
purchase order. Check and record the serial numbers and
model numbers for future reference when ordering parts.
Serial # _____________________________________
Model # _____________________________________
Figure 1
Switch Tripped
Swing out
position
LL
Figure 2
Switch Released
