2100 and 2100E Liquid Level Switches
Instruction Manual
Form 5039
December 2005
5
number of bends and elbows. The vent
line should be as short as possible.
Protect the end of the vent pipe from
the entrance of rain, snow, insects, or
any other foreign material that may
plug the vent line. Inspect the vent line
opening periodically to ensure that it
is not plugged.
If necessary to change to a different supply
pressure, install a different nozzle according to steps
1 through 4 and 15 through 18 of the Type 2100
switch maintenance procedure.
To change switch action from low-level to high-level
switching or vice versa, reverse the positions of the
nozzle, flapper, and magnet according to steps 1
through 7 and 10 through 18 of the Type 2100
switch maintenance procedure.
To change switch mounting from right-hand to
left-hand or vice versa, perform steps 1 through 7
and 9 through 18 of the Type 2100 switch
maintenance procedure.
Additional Procedures for Type 2100E
Switch
Refer to figure 6.
To install for standard action, connect electrical
wires as shown in table 2.
To change switch action from low-level to high-level
switching, or vice versa, perform steps 1 through 4
and 13 through 17 of the Type 2100E maintenance
procedure.
To reverse action of the Type 2100E switch, refer to
table 2 and reinstall wiring for normally open (NO)
switches to normally closed (NC) and vice versa.
To change switch mounting from right-hand to
left-hand or vice versa, perform steps found in the
Type 2100 switch maintenance procedure.
Calibration Check
For either type of switch, calibration can be checked
by varying the level of the process liquid in the cage
and observing the switch operation.
If the process connection directly on top of the cage
is not piped to the tank, close the isolating valves
Table 2. Type 2100E Wiring Codes
Wire
Color
SPDT
DPDT Switch 1
DPDT Switch 2
Red
Brown
Blue
Green
Black
Yellow
Purple
Normally Closed
Common
Normally Open
Ground
Normally Closed
Common
Normally Open
Ground
Ground
Normally Closed
Common
Normally Open
and fill the cage with process liquid through the top
connection. Verify that the switch operates as the
cage is being filled. Repeat the calibration procedure
if necessary.
Calibration can also be checked on the work bench.
Connect a flexible hose from one of the bottom
process connections to the bottom of a bucket. The
top process connection should be open. Fill the
bucket with process liquid. As the bucket is raised or
lowered, the liquid level in the displacer cage rises or
falls. Verify that the switch operates as the level is
varied. Repeat the calibration procedure if
necessary.
Dry calibration can be performed on the Type 2100E
using the following procedure:
Refer to figure 6.
1. Position the cage and displacer assembly (key 1)
so that the displacer is hanging downward.
2. Level the switch arm (key 40), if required.
3. Loosen the locknut (key 33) and adjust the
machine screw (key 31) until it contacts the switch.
4. For low-level dry calibration, tighten the locknut.
For high-level dry calibration, turn the machine
screw one additional full turn, then tighten the
locknut.
Principle of Operation
The Type 2100 switch (figure 4) is an external,
cage-mounted, pneumatic liquid level switch. When
the switch is in the normal position with the flapper
against the nozzle, output pressure cannot bleed off
and remains the same as full supply pressure.
Rising liquid level exerts a buoyant force on the
displacer, producing a torque in the torque tube.
When this torque exceeds the torque exerted on the
flapper by the magnet, the flapper snaps away from
the nozzle. This action allows output pressure to
bleed through the nozzle faster than supply pressure
can enter through the bleed orifice.
