Instruction Manual
D200126X012
2502 Controllers
June 2017
13
the sensor is to the right of the controller, remove the two mounting screws, turn the dial over so the arrow points to
the right, then reinstall the mounting screws.
On a controller with optional level indicator assembly the travel indicator plate is printed on both sides. If the sensor is
to the left of the controller (right‐hand mounting), use the side of the plate that has the arrow pointing to the left. If
displacer is to right of controller (left‐hand mounting), use the side of the plate that has the arrow pointing to the
right.
1. Turn on the supply pressure and check that the controller supply gauge reads 1.4 bar (20 psig) for a 0.2 to 1.0 bar
(3 to 15 psig) output pressure range or 2.4 bar (35 psig) for a 0.4 to 2.0 bar (6 to 30 psig) output pressure range. If
the pressure is incorrect, loosen the locknut of the filter/regulator (figure 3); turn the adjusting screw clockwise to
increase or counterclockwise to decrease pressure. Tighten the locknut after setting the pressure.
2. Turn the reset control to .05 minutes per repeat.
3. Locate the process variable at its minimum value (see table 2). Zero the proportional band and raise level controls.
Output pressure on direct‐acting controllers should be greater than zero but less than 0.2 bar (3 psig) for the 0.2 to
1.0 bar (3 to 15 psig) range or 0.4 bar (6 psig) for the 0.4 to 2.0 bar (6 to 30 psig) range. For reverse‐acting
controllers, the output pressure should be greater than 1.0 bar (15 psig) and less than 1.4 bar (20 psig) for the 0.2 to
1.0 bar (3 to 15 psig) range or greater than 30 psig (2.0 bar) and less than 3.4 bar (35 psig) for the 0.4 to 2.0 bar
(6 to 30 psig) range. If these conditions are not met recalibration may be desired. On a controller with indicator
assembly, the pointer should be over the low point on the indicator plate; slight adjustment might be necessary by
loosening the hex nut (key 40, figure 14), shifting the pointer, and retightening the nut.
be greater than 1.0 bar (15 psig) and less than 1.4 bar (20 psig) for the 0.2 to 1.0 bar (3 to 15 psig) range or greater
than 2.0 bar (30 psig) and less than 3.4 bar (35 psig) for the 0.4 to 2.0 bar (6 to 30 psig) range. If these conditions
are not met, recalibration may be desired. On a controller with indicator assembly, the pointer should be over the
high point on the indicator plate; slight adjustment might be necessary by loosening the hex nut (key 40, figure 14),
shifting the pointer and retightening the nut.
On a controller with level indicator, the pointer should reflect the magnitude of the process variable; for instance,
with liquid or interface level covering 50 percent of the displacer, the pointer should be in the middle of the
high‐low scale. Slight plate adjustment might be necessary as described at the end of step 3.
5. If all prestartup checks are satisfactory proceed to the Startup section.
Adjustments
Controller adjustments are provided in this section. Refer to figure 9 for adjustment locations.
Level Set Adjustment
To perform the level adjustment, open the controller cover, loosen the knurled adjustment screw (see figure 9), and
rotate the adjustment lever around the RAISE LEVEL dial. To raise the fluid or interface level, or increase density, rotate
this knob in the direction of the arrows. To lower the level or decrease density, rotate the knob in the opposite
direction. This procedure is the same for both direct and reverse action controllers. Tighten the knurled screw.
Note
The RAISE LEVEL dial does not reflect actual fluid level in the tank or fluid level position on the displacer.
Proportional Band Adjustment
Proportional band adjustment is made to change the amount of displacement force change required to obtain full
output pressure change, by determining the percentage of pressure fed back to the proportional bellows. The
