Emerson Fisher 2502 Instruction Manual Download

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Instruction Manual

D200126X012

2502 Controllers

June 2017

Figure 14. Fisher 2502 Controller Constructions

30A8942‐H

43A2366‐H

30A8943‐H

TYPICAL CONTROLLER

DETAIL OF RELIEF VALVE ASSEMBLY

ON 2502F CONTROLLER

DETAIL OF LEVEL INDICATOR ASSEMBLY

ON 2502C CONTROLLER

Summary of Contents for Fisher 2502

Page 1: ...s 15 Wet Calibration 15 Dry Calibration 15 Controller and Torque Tube Arm Disassembly 16 Determining Suspended Weight for Calibration 16 Calibration Procedure 17 Startup 18 Principle of Operation 19 2502 Controller 21 2502F Controller with Reset Relief Valve 21 Maintenance 22 Troubleshooting 23 Removing Controller from Sensor 24 2502 CONTROLLER 249B SENSOR W8334 Figure 1 Fisher 2502 Controller Mou...

Page 2: ...ions about these instructions contact your Emerson sales office or Local Business Partner before proceeding Description The 2502 controller described in this manual provides proportional plus reset and proportional plus reset with differential relief valve control The controller output is a pneumatic signal that operates a final control element These controllers are designed to control liquid leve...

Page 3: ...nt Class 3 Pressure Dew Point Class 3 or at least 10_C less than the lowest ambient temperature expected Supply Pressure Requirement 1 4 bar 1 20 psig for 0 2 to 1 0 bar 3 to 15 psig output signal or 2 4 bar 1 35 psig for 0 4 to 2 0 bar 6 to 30 psig output signal Maximum Supply Pressure 2 3 4 bar 50 psig Supply Pressure Consumption 3 At 1 4 bar 20 Psig Minimum 0 11 normal m3 h 4 2 scfh at proporti...

Page 4: ...IENT DEWPOINT IS ABOVE PROCESS TEMPERATURE ICE FORMATION MAY CAUSE INSTRUMENT MALFUNCTION AND REDUCE INSULATOR EFFECTIVENESS 0 20 40 60 80 100 120 140 160 0 10 20 18 10 30 40 50 60 70 71 593 500 400 300 200 100 0 0 400 800 110 0 20 29 NO INSULATOR NECESSARY AMBIENT TEMPERATURE _C STANDARD CONTROLLER OR TRANSMITTER AMBIENT TEMPERATURE _F HEAT INSULATOR REQUIRED TOO HOT NOTE FOR SERVICE BELOW 29_C 2...

Page 5: ... 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 fi...

Page 6: ...aining of accumulated moisture The controller is attached to the sensor in one or the other of the mounting positions shown in figure 4 Right hand with the case to the right of the displacer when looking at the front of the case or left hand with the case to the left of the displacer The mounting position can be changed in the field if required refer to the appropriate sensor manual for instructio...

Page 7: ...l transmit an erroneous output signal Note If the controller is not mounted on the sensor refer to the Installing Controller on Sensor section This section also provides instructions for adding a heat insulator to a unit Cage connections will normally be either NPS 1 1 2 or 2 screwed or flanged Figure 5 shows the combinations With flanged connections use standard gaskets or other flat sheet gasket...

Page 8: ...ort should be installed in each of the equalizing lines Also install a drain between the cage and shutoff or hand valve whenever the bottom cage line has a liquid trapping low point On liquid or interface level applications position the sensor so that the line marked FLOAT CENTER on the cage is located as close as possible to the center of the liquid level or interface level range being measured A...

Page 9: ...ass on the vessel CAUTION If the displacer is to be inserted into the vessel before being attached to the displacer rod provide a suitable means of supporting the displacer to prevent it from dropping into the vessel and suffering damage To help support a 249BP or 249CP displacer install the displacer stem and stem end piece or a threaded rod into the 1 4 inch 28 UNF threaded hole in the displacer...

Page 10: ...ted cageless sensor The displacer may be attached to the displacer rod before installing the sensor on the vessel Where the displacer diameter is small enough it may be desirable to install a long or sectionalized displacer through the sensor head access hole after the sensor is installed on the vessel Connect the displacer as shown in figure 8 locking the assembly with the cotter springs provided...

Page 11: ...ons field office and industry instrument air quality standards for use with corrosive gas or if you are unsure about the proper amount or method of air filtration or filter maintenance 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 pneumati...

Page 12: ...heck the vent periodically to be certain it has not become plugged Prestartup Checks WARNING The following procedure requires taking the controller out of service To avoid personal injury and property damage caused by an uncontrolled process provide some temporary means of control for the process before taking the controller out of service Adjustment locations are shown in figure 9 unless otherwis...

Page 13: ...ht be necessary by loosening the hex nut key 40 figure 14 shifting the pointer and retightening the nut 4 Locate the process variable at its maximum value see table 2 Output pressure on direct acting controllers 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 2 0 bar 30 psig and less than 3 4 bar 35 psig for the 0 4 to ...

Page 14: ...e time in minutes required for the reset action to produce a correction which is equal to the correction produced by proportional control action This is in effect the time in minutes required for the controller to increase or decrease its output pressure by an amount equal to a proportional increase or decrease caused by a change in control conditions Figure 9 Controller Adjustments RESET ADJUSTME...

Page 15: ...he shop but other means of obtaining a displacement force change must be provided It must be done in the shop if the process variable is not available for calibration or if the process cannot be varied for calibration There are two methods of adapting the calibration procedure to shop calibration wet and dry Wet Calibration Remove the entire controller and sensor assembly from the vessel For caged...

Page 16: ... into the 1 4 inch 28 UNF threaded hole in the displacer spud or stem end piece of top mounted cageless and all caged sensors For some top mounted sensors with long displacers it may also be possible to remove the sensor through the access hole in the sensor head For the 249BP sensor with the travel stop the stem end piece pins will secure the displacer as long as the travel stop plate is installe...

Page 17: ... damage caused by an uncontrolled process provide some temporary means of control for the process before taking the controller out of service Figure 9 shows adjustment locations for the following steps except as otherwise indicated When calibrating open loop conditions must exist One way to obtain an open loop is to place the final control element into manual control or bypass it If there is no pr...

Page 18: ...en the two calibration adjuster screws key 45 figure 14 and slide the calibration adjuster key 100 figure 14 in the desired direction a If output is below 1 0 bar for a 0 2 to 1 0 bar signal range 15 psig for a 3 to 15 psig signal range or 2 0 bar for a 0 4 to 2 0 bar signal range 30 psig for a 6 to 30 psig signal range move the adjustor a small distance away from the pivot to increase span moveme...

Page 19: ...te a load upset If cycling occurs broaden the proportional band slightly and repeat the load upset until stability is attained In general the narrowest proportional band and the highest reset setting that will not produce cycling will provide the best control Principle of Operation All 2502 controllers use the same basic pressure balanced relay with a yoked double diaphragm assembly figure 10 This...

Page 20: ...SPRINGS LEVEL SET ADJUSTMENT RESET BELLOWS FIXED PIVOT BEAM AND FLAPPER CAM RESET VALVE PROPORTIONAL VALVE FIXED RESTRICTION EXHAUST END OF RELAY VALVE LARGE DIAPHRAGM OF ASSEMBLY SMALL DIAPHRAGM OF ASSEMBLY INLET END OF RELAY VALVE SUPPLY PRESSURE REGULATOR DIRECT ACTING DIAPHRAGM CONTROL VALVE VESSEL INFLOW PROPORTIONAL PRESSURE SUPPLY PRESSURE OUTPUT PRESSURE NOZZLE PRESSURE RESET PRESSURE EXHA...

Page 21: ...its supply pressure to bleed through the nozzle faster than it can enter through the fixed restriction This builds up the loading differential on the side of the small diaphragm and opens the relay valve to exhaust loading pressure The three way proportional valve can be opened and adjusted to allow some or all of the output pressure change to feed back to the proportional bellows in order to chan...

Page 22: ...ncrease in the proportional bellows and in the outer relief valve chamber If the outer chamber pressure exceeds that in the inner relief valve chamber by the amount of the relief pressure setting the relief diaphragm will move off the orifice in the relief valve and the pressure in the outer chamber will bleed into the reset system This action provides quick relief of excessive proportional pressu...

Page 23: ...readily available The output signal measuring device should have a corresponding accuracy Table 3 lists some common operating faults their probable causes and corrective action Table 3 Troubleshooting Chart for Fisher 2502 Controllers Fault Possible Cause Check Correction 1 Process wanders or cycles around setpoint 1 1 Proportional band or specific gravity adjustment incorrect or improperly tuned ...

Page 24: ...ent 3 2 Insure the flapper is not loose on the torque tube shaft and is centered on the nozzle 3 2 Replace or tighten flapper assembly as necessary and or center flapper on nozzle 3 3 Process variable changed 3 3 Insure the process variable has not changed from original calibration settings or from displacer design specific gravity 3 3 Change process variable back to original specification or reca...

Page 25: ...eat insulator to the torque tube arm Pull the case straight out from the torque tube arm easing it over the shaft coupling key 36 figure 12 if one is installed Figure 12 Heat Insulator Shown Installed on Fisher 249 Sensor 20A7423 C 4 If the controller has a heat insulator remove the button head cap screws key 40 Remove four washers key 53 and the insulator assembly key 35 Changing Mounting Method ...

Page 26: ...stall the controller on the torque tube arm in the shop then calibrate and return the controller and torque tube arm assembly to the installation Perform step 1 only if adding a heat insulator to a unit that does not have one Key numbers in this step are shown in figure 12 unless otherwise indicated 1 To install the heat insulator secure the shaft extension key 37 to the torque tube assembly rotar...

Page 27: ...process variable at the detection point 4 Change the process variable in the opposite direction until another output pressure change can be detected and again record the value of the process variable If the difference between the two recorded values the dead band is more than 0 2 percent of the maximum displacer length the relay will have to be replaced or repaired according to the Changing Relay ...

Page 28: ...tion and replace rings as necessary 2 Install the nozzle block seal rings and screws on the opposite side of the beam as shown in figure 13 Disconnect the proportional band tubing key 76 and one of the two pieces of reset tubing key 75 from the bellows frame key 94 and reconnect them in the proper orientation as shown in figure 13 Figure 13 Nozzle Flapper and Tubing Arrangements for Various Action...

Page 29: ...omponents not supplied by Emerson Automation Solutions may void your warranty might adversely affect the performance of the instrument and could cause personal injury and property damage Parts Kits Description Part Number Controller Parts Kit Contains keys 12 15 21 24 38 55 57 58 60 62 63 64 77 79 84 86 87 93 101 and 187 Standard Temperature R2502X00L52 High Temperature R2502X00H52 Relay Replaceme...

Page 30: ...l 2 req d Key Description 44 Machine Screw steel pl 4 req d 45 Machine Screw stainless steel 2 req d 47 Spring not shown stainless steel 49 Machine Screw stainless steel 13 req d 50 Screen stainless steel 51 Pointer Ass y 2502C and 2502FC stainless steel brass pl 53 Base Plate aluminum 2502C and 2502FC 54 Front Plate aluminum 2502C and 2502FC 55 O Ring 3 req d Standard nitrile High temperature flu...

Page 31: ...2502 Controllers June 2017 31 Figure 14 Fisher 2502 Controller Constructions 30A8942 H 43A2366 H 30A8943 H TYPICAL CONTROLLER DETAIL OF RELIEF VALVE ASSEMBLY ON 2502F CONTROLLER DETAIL OF LEVEL INDICATOR ASSEMBLY ON 2502C CONTROLLER ...

Page 32: ...embly stainless steel 36 Shaft Coupling stainless steel 37 Shaft Extension N05500 38 Set Screw stainless steel 2 req d 39 Cap Screw steel pl 4 req d 40 Cap Screw steel pl 4 req d 53 Washer carbon steel pl 4 req d Recommended spare parts Emerson Automation Solutions Marshalltown Iowa 50158 USA Sorocaba 18087 Brazil Cernay 68700 France Dubai United Arab Emirates Singapore 128461 Singapore www Fisher...

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