Instruction Manual

Instruction Manual
D103531X012
L2e Controller
June 2014
11
Principle of Operation
The operation of the L2e is based on Archimedes Principle, which states that a body immersed in a liquid will be
buoyed up by a force equal to the weight displaced. The buoyant force and resultant movement of the displacer in the
liquid is transmitted to the controller. As the buoyant force changes a proportional change in movement is seen by
levers A and B (refer to figure 7). Levers A and B are arranged and connected by movable pivot or span adjustment so
that the resultant movement between the plunger and the switch can be adjusted. For a given change in displacer
movement the span adjustment will increase or decrease a proportional change in the plunger movement. As fluid
level rises, the plunger moves away from the switch and vice versa.
Figure 7. Fisher L2e Controller
SWITCH
SPAN
ADJUSTMENT
LEVER B
GG10047
w/Displacer Rod
PLUNGER
FACTORY SET - DO NOT ADJUST
LEVER A
CONTROLLER MOUNTING
SCREWS (KEY 24)
ZERO SPRING
(KEY 7)
ZERO ADJUSTMENT
DISPLACER
ROD (KEY 64)
ZERO ADJUSTMENT
HEX NUT (KEY 5)