Instruction Manual
D200126X012
2502 Controllers
June 2017
5
WARNING
Personal injury or property damage may result from fire or explosion if natural gas is used as the supply medium and
preventive measures are not taken. Preventive measures may include, but are not limited to, one or more of the following:
Remote venting of the unit, re‐evaluating the hazardous area classification, ensuring adequate ventilation, and the
removal of any ignition sources. For information on remote venting of this controller refer to page 12.
CAUTION
Do not use sealing tape on pneumatic connections. This instrument contains small passages that may become obstructed
by detached sealing tape. Thread sealant paste should be used to seal and lubricate pneumatic threaded connections.
249 Sensors
D
249, 249B, 249BF, 249C, 249K, and 249L sensors side‐mount on the vessel with the displacer mounted inside a cage
(caged) outside the vessel.
D
249BP and 249CP sensors top‐mount on the vessel with the displacer hanging down into the vessel (cageless).
D
The 249VS sensor side‐mounts on the vessel with the displacer hanging out into the vessel (cageless).
D
The 249W sensor top‐mounts on the vessel or on a customer supplied cage.
External sensors provide more stable operation than do internal sensors for vessels with internal obstructions or
considerable internal turbulence.
WARNING
When replacing the sensor assembly, the displacer may retain process liquid or pressure. Personal injury or property
damage due to sudden release of pressure, contact with hazardous liquid, fire, or explosion can be caused by puncturing,
heating, or repairing a displacer that is retaining process pressure or liquid. This danger may not be readily apparent when
disassembling the sensor or removing the displacer. Before disassembling the sensor or removing the displacer, observe
the more specific warning provided in the sensor instruction manual.
Uncrating
Unless ordered separately, the controller will be attached to the sensor when shipped. Carefully uncrate the assembly.
CAUTION
If the sensor has a thin‐walled torque tube, always support the displacer if the travel stop must be removed. A thin‐walled
torque tube has a T stamped on the sensor end flange (not visible unless the controller is removed from the sensor).
Note
Caged sensors have a rod and block installed on each end of the displacer to protect the displacer in shipping. Remove these parts
before installing the sensor to allow the displacer to function properly.
