Instruction Manual
D200124X012
2500 and 2503 Controllers/Transmitters
June 2017
26
7. Slowly increase the process variable until the output pressure switches:
D
For Direct Acting Controllers
, slowly increase the process variable until the output pressure switches to full supply
pressure. The process variable should be at the maximum value of input range as shown in table 6. If the process
variable agrees with table 6, proceed with step 8. If the process variable does not agree with table 6, proceed to
step 9.
D
For Reverse Acting Controllers
, slowly increase the process variable until the output pressure switches to 0 bar (0
psig). The process variable should be at the maximum value of input range as shown in table 6. If the process
variable agrees with table 6, proceed with step 8. If the process variable does not agree with table 6, proceed to
step 9.
8. If the unit does not contain an indicator assembly, go to the startup section. If the unit contains an indicator
assembly, change the pointer span by loosening the indicator plate screws (key 41, figure 16, indicator assembly
detail), slide the plate until the HIGH mark is under the pointer. Tighten the plate screws and go to the startup
section.
Note
base (key 27) right or left along the elongated slotted hole as follows:
D
To
decrease
the differential gap, slide the flexure strip base away from the torque tube shaft.
D
To
increase
the differential gap, slide the flexure strip base toward the torque tube shaft.
Retighten the screws. For the 2500S only, if the flexure strip base has been moved as far as possible and the differential
gap is still too low, proceed to step 11.
10. Repeat the procedure from step 4 until the required calibration points are obtained.
Note
Any change in the PROPORTIONAL BAND adjustment in the following step changes the zero as well as the differential gap.
11. If the flexure strip base has been moved as far as possible and the differential gap is still too large or too small,
adjust the PROPORTIONAL BAND as follows:
D
If the differential gap is too large, slightly decrease the PROPORTIONAL BAND setting.
D
If the differential gap is too small, slightly increase the PROPORTIONAL BAND setting.
12. Repeat the procedure from step 4 until the required calibration points are obtained.
Note
If you cannot calibrate the controller, look for other problems as described in the Troubleshooting procedures, such as a nozzle
that is not perpendicular to the flapper, leaky connections, or a binding displacer rod. If none of these troubles are apparent,
ensure the displacer is sized correctly for the application.
