Preliminary Checks; Direct-Acting Throttling Controllers - Emerson Fisher l2 Instruction Manual

Type L2
SPAN LEVER GAP
MOST SENSITIVE POSITION FOR THROTTLING
AND ON/OFF CONTROLLER. LEAST SENSITIVE
POSITION FOR SNAP-ACTING CONTROLLER
LEVER A CONTACTING THE DISPLACER ROD
LEAST SENSITIVE POSITION FOR THROTTLING AND ON/OFF CONTROLLER.
MOST SENSITIVE POSITION FOR SNAP-ACTING CONTROLLER
GB0137–2
E0787

Preliminary Checks

1. Check the supply pressure gauge (key 10) to be
certain that the supply pressure is at the desired
value. Adjust the supply pressure as required.
2. Adjust the displacer rod to the horizontal position
with the spring adjustment (key 4).
3. Bounce the end of the displacer rod (key 64,
figure 7) up and down to check that the sensor is
operating freely.
4. Place the span adjuster (key 9) at the desired
position (see figure 5).
6
Figure 5. Proportional Band Adjustments
5. Check figures 3 and 4 for correct control action
and control mode.
6. Adjust the relay adjustment screw (key 49,
throttling controller) or the valve assembly (key 51,
snap-acting controller) so that the gap between the
span levers (see figure 5) is equal when lever A is
contacting the displacer rod.

Direct-Acting Throttling Controllers

1. Make certain the Preliminary Checks procedure
at the start of this section has been completed.
2. Lower the liquid level so that it is below the
bottom of the displacer or at the lowest desired
LEVER A
LEVER B
Instruction Manual
Form 5732
December 2001