Instruction Manual
D200124X012
2500 and 2503 Controllers/Transmitters
June 2017
14
assembly do not form a gas‐tight seal when the assembly is enclosed, a remote vent line, adequate ventilation, and
necessary safety measures should be used to prevent the accumulation of flammable or hazardous gas. However, a remote
vent pipe alone cannot be relied upon to remove all flammable and hazardous gas. Vent line piping should comply with
local and regional codes, and should be be as short as possible with adequate inside diameter and few bends to reduce case
pressure buildup.
CAUTION
When installing a remote vent pipe, take care not to overtighten the pipe in the vent connection. Excessive torque will
damage the threads in the connection.
The vent assembly (see figure 9) or the end of a remote vent pipe must be protected against the entrance of all foreign
matter that could plug the vent. Use 13 mm (1/2-inch) pipe for the remote vent pipe, if one is required. Check the vent
periodically to be certain it has not become plugged.
Prestartup Checks
Adjustments are shown in figure 10 unless otherwise indicated. Open‐loop conditions must exist when performing the
prestartup checks. To obtain open‐loop conditions:
D
make sure there is no process flow through the final control element, or
D
disconnect the controller/transmitter output signal line and connect it to a pressure gauge.
During prestartup, the displacer must be positioned from its maximum to its minimum range of operation. Provide a
means to change the process variable (the process level or interface). If the process variable cannot be varied
sufficiently, use the precalibration procedures in the Calibration section to simulate the process variable changes
required for these checks.
Make sure the RAISE LEVEL dial on the controller is mounted with the correct side facing out. The dial is marked on
both sides with an arrow. The arrow points to the left on one side and to the right on the other. When the sensor is
mounted to the left of the controller/transmitter, the arrow on the raise level dial should point to the left, as shown in
figure 10. If the sensor is to the right, the arrow should point to the right. If necessary, remove the two mounting
screws, turn the dial over so the arrow points correctly, and reinstall the mounting screws. The level directions shown
on the dial will be correct for both direct‐acting and reverse‐acting controllers. For a transmitter, use the same side of
the ZERO ADJUSTMENT dial for both right‐ and left‐hand sensor mountings.
On a controller or transmitter with an optional mechanical indicator assembly, the travel indicator plate is also marked
with an arrow on both sides. If the sensor is to the left of the controller/transmitter, the arrow on the plate should
point to the left. If the sensor is to the right, the arrow should point to the right. If necessary, reinstall the plate so that
the arrow points in the correct direction.
