Type 2390 and 2390B Liquid Level Transmitters

Transcription

1 Instruction Manual Form 5233 May 1999 Type 2390 and 2390B Type 2390 and 2390B Liquid Level Transmitters Contents Introduction... 2 Scope of Manual... 2 Product Description... 2 Type 2390 and 2390B Transmitters Series Sensors... 2 Specifications... 2 Test Equipment and Tools Required... 4 Installation... 5 Pre-installation Requirements... 6 Direct or Reverse Action Setup Verification... 6 Transmitter Orientation... 6 Mounting the Transmitter on a 249 Series Sensor... 8 Mounting the Transmitter for High Temperature Applications... 8 Wiring... 9 Calibration Precalibration Considerations Matching the Transmitter to a 249 Series Sensor Setup Coupling Zero and Span Adjustment Recording the Sensor Span Securing the Unit for Shipment or Placing the Unit In Service Determining Suspended Weight for Calibration Dry Calibration Principle of Operation Maintenance Troubleshooting Checking Transmitter Hall-Effect Sensor Assembly Checking the Analog Output Meter Removing the Transmitter from a 249 Series Sensor Series Sensor in Standard Temperature Application Series Sensor in High Temperature Application W4078/IL TYPE 2390 OR 2390B LIQUID LEVEL TRANSMITTER W4067-1*/IL TYPE 2390 OR 2390B LIQUID LEVEL TRANSMITTER CAGED TYPE 249B SENSOR Figure 1. Type 2390 or 2390B Liquid Level Transmitter and Typical Sensor Printed Wiring Board Compartment Parts Removal and Replacement Removing the Analog Output Meter Removing the Printed Wiring Board Assembly 22 Removing a Potentiometer Assembly Removing and Re-installing the Transmitter Hall-Effect Sensor Assembly Re-installing a Potentiometer Assembly Re-installing a Printed Wiring Board Assembly 22 Re-installing the Analog Output Meter D200364X012

2 Contents (Continued) Sensor Connection Compartment Parts Removal and Re-installation Removing the Lever Assembly Removing and Replacing the Flexure Strips.. 23 Removing the Dry Span Scale Re-installing the Dry Span Scale Re-installing the Lever Assembly Parts Ordering Repair Kits Parts List Type 2390 and 2390B Liquid Level Transmitters Series Sensor Insulator Assembly Introduction Scope of Manual This instruction manual provides installation, calibration, maintenance, and parts ordering information for the Type 2390 and 2390B liquid level transmitters used with the 249 Series level sensors. A typical transmitter-sensor combination is shown in figure 1. Refer to the Principle of Operation section for a more comprehensive discussion of how the Type 2390 and 2390B liquid level transmitters operate. Only personnel qualified through training or experience should install, operate, and maintain this transmitter. If there are any questions concerning these instructions contact your Fisher Controls sales office or sales representative before proceeding. This manual does not include sensor installation instructions, maintenance instructions, or parts lists. For this information, refer to the appropriate sensor instruction manual. Product Description Type 2390 and 2390B Transmitters The Type 2390 or 2390B liquid level transmitter is used with the 249 Series sensors to measure changes in liquid level, the level of interface between two liq- Figure 2. Typical Nameplate uids, or the specific gravity (density) changes of a liquid. These changes exert a buoyant force on the displacer, which rotates the torque tube shaft. This rotary motion is applied to the transmitter, and the resulting current output signal is sent to an indicating or final control element. A wide variety of 249 Series sensors are used with the Type 2390 or 2390B transmitters. 249 Series Sensors! The Type 249, 249B, 249BF, 249C, 249K, 249L, and 249N sensors side-mount on the vessel with the displacer mounted inside a cage outside the vessel. (The Type 249BF is available only in Europe, Middle East, and Africa.) These sensors are called caged sensors.! The Type 249BP, 249CP, and 249P sensors topmount on the vessel with the displacer hanging down into the vessel. These sensors are called cageless sensors.! The Type 249V sensor side-mounts on the vessel with the displacer hanging out into the vessel (cageless sensor). Specifications Specifications for a Type 2390 or 2390B transmitter are listed in table 1. Some specifications for an individual transmitter, as it comes from the factory, are found on the nameplate (figure 2). 2

3 Transmitter Input Signal (1) Liquid level, interface level, or density changes move the displacer up or down to provide rotary motion to the torque tube shaft Transmitter Output Signal (1) 4 to 20 milliamperes (ma) dc (direct action increasing input increases transmitter output; or reverse action increasing input decreases transmitter output) Transmitter Performance (Transmitter Only) (Specific Gravity of 1.0) Transmitter Output Reference Accuracy (1) :!0.5% of full scale output Hysteresis (1) :!0.1% of full scale output Repeatability (1) :!0.1% of full scale output Dry Span Calibration:!2.5% of full scale at a specific gravity of 1.0 Optional Analog Output Meter Accuracy:!2.5% of full scale Frequency Response: A second order fit of the combined torque tube and transmitter transfer function is characterized by a natural frequency (! n )of 3 radians/second and a damping ratio (") of 0.9. The 3 db point (90" phase shift) occurs between 0.4 and 0.5 Hz. Transmitter Performance With 249 Series Sensor (2) (Specific Gravity of 1.0, Standard Torque Tube) Independent Linearity (1) :!0.75% of full scale output Hysteresis (1) : 0.4% of full scale output Transmitter Operating Influences (1) Electromagnetic Interference (EMI) (1) : With transmitter covers on, product meets requirements of SAMA standard PMC ; Class 3-abc output changes less than!0.5% of actual span when operated in an electromagnetic field strength of 30 V/m [this is equivalent to a 5-watt, 20 to 1000 MHz radio transmitter operating 19 inches (0.5 m) from the level transmitter] Power Supply Effect: Output signal changes less than!0.002% of full scale output per 1.0 volt change in power supply voltage between 11 and 45 volts dc Transmitter Power Supply Requirements (3) Figure 3 Standard Transmitter: 11 to 45 volts dc with reverse polarity protection Table 1. Specifications Continued CSA and SAA Certified or FM Approved Transmitter (2390): 11 to 30 volts dc for intrinsically safe or 11 to 30 volts dc for flameproof units LCIE or PTB (CENELEC) Approved Transmitter (2390B): 11 to 32.5 volts dc for intrinsically safe (PTB) and 11 to 45 volts dc for flameproof (LCIE) units Transmitter Span Adjustment 10 to 100% of displacer length for level applications using a standard volume displacer Transmitter Zero Adjustment 100% of displacer length Transmitter Environmental Protection Enclosure Protection Type 2390: Meets NEMA 4X, CSA Type 4X, and IP65 ratings Type 2390B: Meets EN IP66 rating Complies with the European EMC directive Transient Power Surge Protection: No damage for a line-to-line power surge of up to 100 kilowatts for 100 nanoseconds, or 1.5 kilowatts for 1 millisecond Transmitter Hazardous Area Classification Refer to the Hazardous Area Classifications bulletins for appropriate approvals Transmitter Weight 7.7 pounds (3.5 kg) Standard Sensor Displacer Volumes Type 249C, 249CP Displacers: 60 cubic inches (983 cm 3 ) All Other Displacers: 100 cubic inches (1639 cm 3 ) Minimum Sensor Differential Specific Gravity 0.1 with standard volume displacers Mounting Positions Transmitter may be right or left hand mounted on sensor. All level sensors with cage displacers have a rotatable head. The head can be rotated through 360 degrees to any of eight different positions as shown in figure 8 Caged Sensor Connection Styles Cages can be furnished in a variety of end connection styles to facilitate mounting on vessels; the equalizing connection styles are numbered and are shown in figure 4 3

4 Table 1. Specifications (continued) Operating Limits Process Temperature: See table 3 and figure 11 Ambient Temperature and Humidity: See below Conditions Normal Limits (1) Ambient 40 to 176"F Temperature (1) ( 40 to 80"C) Ambient Relative Humidity Transport and Storage Limits (1) 58 to 176"F ( 50 to 80"C) Nominal Reference (1) 77"F (25"C) 10 to 95% 10 to 95% 40% 1. These terms are defined in ISA Standard S Specific gravity of 1.0 on standard wall torque tube with full input change. 3. All versions have reverse polarity protection. TOOL Hex nut driver Allen head wrench Open-end wrench Allen head wrench Open-end wrench Open-end wrench Open-end wrench Allen head wrench Allen head wrench Allen head wrench Table 2. Additional Tools Required COMPONENT Shaft clamp Shipping screw Cam disk assembly Heat insulator Mounting hex nuts Vent plug Eccentric pin Flexure screws Lever assembly adjustment Eccentric pin lock TOOL SIZE FOR TYPE 2390 OR 2390B TRANSMITTER Type 2390, Inches Type 2390B, mm 11/32 9/64 9/32 5/64 1/2 15/16 3/16 3/32 9/64 5/64 Allen head wrench Cover, CENELEC flameproof 5/ Table 3. Allowable Process Temperatures for Common 249 Sensor Component Materials Process Temperature Material Min. Max. Cast Iron 20"F ( 29"C) 450"F (232"C) Steel 20"F ( 29"C) 800"F (427"C) Stainless Steel 325"F ( 198"C) 800"F (427"C) N05500 (K-Monel) 325"F ( 198"C) 700"F (371"C) Graphite Laminate/SST Gaskets 325"F ( 198"C) 800"F (427"C) Monel/PTFE Gaskets 100"F ( 73"C) 400"F (204"C) Test Equipment and Tools Required The following equipment is required for installation, calibration, and maintenance of the Type 2390 and 2390B liquid level transmitters.! Power supply capable of supplying up to 24 volts dc in series with a load.! A 4-digit digital voltmeter (DVM), with an impedance of at least 250,000 ohms, that measures voltages in the range of 0 to 10 volts dc with an accuracy of!1 millivolt, and currents in the range of 0 to 50 ma dc with an accuracy of!0.01 ma. LOAD RESISTANCE, OHMS A / IL POWER SUPPLY VOLTAGE, V dc FOR A 4 20 MILLIAMPERE CIRCUIT, MAXIMUM ALLOWABLE LOAD RESISTANCE IS 1700 OHMS CSA CERTIFIED OR FM APPROVED TRANSMITTERS INTRINSICALLY- SAFE AND FLAME-PROOF STANDARD AND LCIE (CENELEC) FLAME-PROOF TRANSMITTERS PTB (CENELEC) INTRINSICALLY-SAFE APPROVED TRANSMITTERS Figure 3. Power Supply Requirements and Load Resistance! Optionally, a 250 ohm,!0.1 percent, 1/2-watt resistor may be used for converting the 4 20 ma transmitter signals to 1 5 volts dc for voltage measurements.! General-purpose multimeter with an input impedance greater than 30,000 ohms per volt.! An alignment tool (part number 1N10323 G012). 4

5 STYLE 1 TOP AND BOTTOM CONNECTIONS, SCREWED (S-1) OR FLANGED (F-1) STYLE 2 TOP AND LOWER SIDE CONNECTIONS, SCREWED (S-2) OR FLANGED (F-2) STYLE 3 UPPER AND LOWER SIDE CONNECTIONS, SCREWED (S-3) OR FLANGED (F-3) STYLE 4 UPPER SIDE AND BOTTOM CONNECTIONS, SCREWED (S-4) OR FLANGED (F-4) 27A0973-A B / IL Figure 4. Style Number of Equalizing Connections! Refer to table 2 for additional tools required. Refer to Repair Kits under Parts List in this instruction manual for a tool kit for the Type 2390 transmitter. Installation WARNING Personal injury or property damage due to sudden release of pressure, contact with hazardous fluid, fire, or explosion can be caused by puncturing, heating, or repairing a displacer that is retaining process pressure or fluid. 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 appropriate warnings provided in the sensor instruction manual. A3789/IL Figure 5. Typical Caged Sensor Mounting The Type 249 sensor is mounted using one of two methods, depending on the specific type of sensor. If the sensor has a caged displacer, it typically mounts on the side of the vessel as shown in figure 5. If the sensor has a cageless displacer, the sensor mounts on the side or top of the vessel as shown in figure 6. The Type 2390 or 2390B transmitter is typically shipped attached to the sensor. If ordered separately, it may be convenient to mount the transmitter to the sensor and perform the matching and initial calibration before installing the sensor on the vessel. 5

6 A5497/IL 2N10065-L A3544-2/il Figure 7. Printed Wiring Board Connections Check that you have received the proper Hazardous Area Approval rating on the transmitter. The nameplate on the transmitter (figure 2) specifies the approval agency (if required) for the transmitter. A3788/IL Figure 6. Typical Cageless Sensor Mounting Pre-installation Requirements 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. Direct or Reverse Action Set-Up Verification Before installing the transmitter, determine that the instrument is set up properly for direct or reverse action. Direct action (increasing level produces an increasing output) or reverse action (increasing level produces a decreasing output) is set up as shown in figure 7, depending on whether the sensor is right- or left-hand mounted. If your transmitter is set up incorrectly, refer to the table in figure 7 before proceeding with the installation. When changing action, the plug must be rotated 180 degrees to insert it in the other socket. (The wires from the plug exit toward the top of the transmitter when in J2 and toward the bottom when in J2.1, in order to engage the locking tangs on the connectors.) On units with an output indicator, the indicator mounting screws may have to be loosened to allow easy access to the J2.1 socket. Transmitter Orientation Mount the transmitter with the vent opening pointing downward to allow accumulated moisture drainage. The transmitter and torque tube arm are attached to the displacer in either a right- or left-hand mounting style, as shown in figure 8. This can be changed in the field on the 249 Series sensors (refer to the appropriate sensor instruction manual). Changing the mount- 6

7 17A8552-A B1874-1/IL 17A8552-A B1875-1/IL Figure 8. Head Mounting Positions for 249 Series Caged Sensor with Rotatable Head (Top View) 7

8 LEVER ASSEMBLY ALIGNMENT ADJUSTMENT 3. Position the transmitter so the vent plug is on the bottom of the transmitter. 4. Carefully slide the mounting studs into the sensor mounting holes until the transmitter is snug against the sensor. 5. Reinstall the hex nuts on the mounting studs and tighten the hex nuts to 88.5 lbf#in (10 N#m). CAM-DISK ASSEMBLY ECCENTRIC PIN ECCENTRIC PIN LOCKING CAP SCREW 4N10233-D A3543-4/IL SHAFT CLAMP VENT PLUG COVER LOCKING SCREW (FLAME-PROOF TYPE 2390B ONLY) Figure 9. Sensor Connection Compartment ing style also changes the effective action, because the torque tube rotation for increasing level, (looking at the protruding shaft), is clockwise in a right hand mounted unit and counterclockwise in a left hand mounted unit. See table in Figure 7 for required configuration adjustment. All caged 249 Series sensors have a rotatable head. That is, the transmitter can be positioned at any of eight alternate positions around the cage as indicated by the position numbers 1 through 8 in figure 8. To rotate the head, remove the head flange bolts and nuts and position the head as desired. Mounting the Transmitter on a 249 Series Sensor Key numbers are referenced in figure 21 or 22 except where otherwise indicated. 1. Remove the vent plug (figure 9) and loosen the shaft clamp (figure 9) with a hex nut driver inserted through the vent plug hole. 2. Remove the hex nuts (key 62) from the mounting studs (key 61). CAUTION Measurement errors can occur if the torque tube assembly is bent or misaligned during installation. Mounting the Transmitter for High Temperature Applications Key numbers are shown in figure 10 except where otherwise indicated. The transmitter requires an insulator assembly when temperatures exceed the limits shown in figure 11. A torque tube shaft extension is required for a 249 Series sensor when using an insulator assembly. CAUTION Measurement errors can occur if the sensor torque tube assembly is bent or misaligned during installation. 1. For mounting a transmitter on a 249 Series sensor, secure the shaft extension (key 37) to the sensor torque tube shaft via the shaft coupling (key 36) and set screws (key 38), with the coupling centered as shown in figure Remove the vent plug (figure 9) and loosen the shaft clamp with the hex nut driver inserted through the vent plug hole. 3. Remove the hex nuts (key 62, figure 21 or 22) from the mounting studs (key 61, figure 21 or 22). 4. Position the insulator (key 35) on the transmitter, sliding the insulator straight over the mounting studs. 5. Re-install the four hex nuts on the mounting studs and tighten the nuts. 6. Carefully slide the transmitter with the attached insulator over the shaft coupling so that the vent plug is on the bottom of the transmitter. 7. Secure the transmitter and insulator to the torque tube arm with four cap screws (key 39). 8. Tighten the cap screws to 88.5 lbf#in (10 N#m). 8

9 MN A7423-C B2707 / IL SENSOR Figure 10. Transmitter Mounting on Sensor in High Temperature Applications TRANSMITTER PROCESS TEMPERATURE ( F) " TOO 325 COLD A4070-B A5494-1/IL Wiring AMBIENT TEMPERATURE ("C) HEAT INSULATOR REQUIRED NO HEAT INSULATOR NECESSARY 100 HEAT INSULATOR REQUIRED AMBIENT TEMPERATURE ("F) STANDARD TRANSMITTER Figure 11. Guidelines for Use of Optional Heat Insulator Assembly 70 TOO HOT NOTES: 1 FOR PROCESS TEMPERATURES BELOW 20"F ( 29"C) AND ABOVE 400"F (204"C) SENSOR MATERIALS MUST BE APPROPRIATE FOR THE PROCESS SEE TABLE IF AMBIENT DEW POINT IS ABOVE PROCESS TEMPERATURE, ICE FORMATION MIGHT CAUSE INSTRUMENT MALFUNCTION AND REDUCE INSULATOR EFFECTIVENESS. WARNING Personal injury or property damage can result if a suitable conduit seal is not installed. For explosion-proof applications, install the seal no more than 18 inches (457 mm) from the transmitter. WARNING "PROCESS TEMPERATURE ( C) To avoid personal injury or property damage, the following special conditions are applicable to the Type 2390B with LCIE approval of flameproof. If there is a possibility that the temperature of the surface to which the transmitter is mounted will exceed 70"C, then the autoignition temperature of the atmosphere surrounding the transmitter must be at least 15"C greater than the surface temperature, but not less than 85"C. For example, a surface temperature of 75"C would require that the atmosphere have an autoignition temperature of at least 90"C. For intrinsically safe applications, refer to the loop schematics at the end of this manual or to instructions supplied by the barrier manufacturer. The transmitter is normally powered by a 24-volt power supply in series with a load. Figure 12 shows typical field wiring. Wire the transmitter as follows: 1. Remove the field wiring compartment cover (key 38, figure 21 or 22) from the housing (key 1, figure 21 or 22). This compartment has two threaded openings available for fittings. For European applications, the Type 2390B can be wired with a conduit entry adapter or cable gland (key 42, figure 22). Figure 12 shows typical field wiring. Be sure to follow all local codes and approvals. 9

10 FIELD WIRING COMPARTMENT P 1 GND LOAD V DC POWER SUPPLY 2 SAFETY GROUND EARTH GROUND TYPE 2390 STANDARD, FM APPROVED OR CSA CERTIFIED TRANSMITTERS FIELD WIRING COMPARTMENT P LOAD V DC POWER SUPPLY 2 TYPE 2390B LCIE (CENELEC) FLAMEPROOF TRANSMITTERS B1983-1/IL 2 NOTES: 1 CABLE IS NO. 14 TO 18 AWG (2.08 TO 0.82 mm 2 ), SHIELDED, TWISTED PAIR WITH DRAIN WIRE. REFER TO NATIONAL AND LOCAL CODES FOR APPROPRIATE GROUNDING REQUIREMENTS. Figure 12. Typical 2-Wire Analog Signal Conditioner Connections 2. Bring the field wiring into the transmitter via one of the two threaded openings. Rigid metal conduit is recommended. Be sure to follow all local installation codes and approvals. 3. Connect the wire from the positive power supply terminal to the positive screw terminal on the terminal block in the field wiring compartment. Connect the positive load connection to the negative screw terminal in the field wiring compartment as shown in figure 12. Connect the wire from the negative power supply terminal to the negative load terminal to complete the loop. WARNING Personal injury or property damage can result from the discharge of static electricity. Connect a 14 AWG (2.08 mm 2 ) ground strap between the transmitter and earth ground when flammable or hazardous gases are present. Refer to national and local codes and standards for grounding requirements. 4. Connect the safety ground (seal the conduit opening) and the earth ground as shown in figure 12. Replace and hand tighten the cover to the housing. When the loop is ready for startup, apply power to the power supply. Calibration Precalibration Considerations A Type 2390 or 2390B transmitter must be matched to a specific Type 249 sensor and then calibrated with that sensor to a specific process requirement. Thus, before a transmitter and sensor combination can be installed for use, matching and calibration must be performed. The matching procedure records the displacer/torque tube rotational span on the transmitter dry span scale. The scale is calibrated so that 0 to 100% represents the nominal design span of 4.4 degrees. The sensitivity of the system varies due to the wide assortment and tolerances of torque tubes and displacer volumes. For standard combinations using water at 70"F (21"C) as the measured liquid, the value of the sensitivity will fall between 85 and 100%. 10

11 Matching is done at the factory, using water with a specific gravity of 1, for transmitter/sensor combinations that are ordered together. Matching must be done in the field when:! the transmitter is ordered separately from the sensor,! the transmitter is replaced in the field,! any time the sensor or sensor parts (torque tube or displacer) are replaced, or! any time the transmitter is disconnected from the torque tube. If the transmitter is disconnected from the torque tube, and none of the other conditions listed occured, then only the coupling steps of the matching procedure need to be performed. One of two methods may be used to match the transmitter to the sensor:! Wet Calibration this method calibrates the instrument by raising and lowering the fluid level while the displacer is in the fluid. This is the most accurate method.! Calibration by Weights this method may be used on the bench, the displacer is removed from the torque tube. Here, computed weights are used to simulate the combined displacer weight and buoyant force. If possible, the system should be coupled and calibrated with the process fluids at the process temperature. When this is impractical or unsafe, various means may be employed to simulate actual process conditions. If the process temperature is close to ambient conditions, simply suspend the displacer to appropriate depths in a liquid having a specific gravity equal to that of the process liquid. For a caged sensor, the liquid used can be poured into the cage. If necessary, water can be used for matching in the shop. If water is used, compensation must be made for the difference between the specific gravity of water and that of the process liquid by scaling the levels used by the fluid specific gravity. If the process temperature will be considerably different than the calibration temperature, the variation in torque tube spring rate with temperature must also be considered. (Ref. TM 18) In some cases calibration by weights may be the only feasible means of simulating the actual process. The various compensations for specific gravity and temperature are accounted for in the calculation of calibration weights. Once the instrument is matched to the sensor using one of the two methods, you can use the Dry Span Scale system to rerange the instrument (change the zero and span). This method artificially drives the mechanical input to the computed set points relative to the nominal calibration supplied by the Wet Calibration or Calibration by Weights methods. Therefore, dry calibration can be performed only after the instrument has been matched to the sensor. A transmitter factory-mounted on a sensor is already matched and does not require the matching procedure. The matching is performed using water with a specific gravity of 1 or with appropriate weights, and the scale is marked at full actual travel (span) and will be the larger value on the appropriate scale. Before starting the matching procedure, confirm that the transmitter is correctly set up and installed on the sensor as described in the Installation section. Matching the Transmitter to a 249 Series Sensor All locations in this procedure are referenced in figure 13 unless otherwise indicated. The transmitter should be installed on the torque tube arm, with the shaft clamp (figure 9) loose. Setup 1. Loosen the door screw on the calibration door and open the door. 2. Remove the red shipping screw. Place the shipping screw in the clip provided in the calibration door for reinstallation after completing the calibration procedures if the unit is to be moved. 3. Connect the transmitter to the test equipment per the calibration setup (figure 14) and turn on the power supply and DVM. Set the DVM to measure milliamperes (ma). 11

12 SPAN POTENTIOMETER ADJUSTMENT SHAFT RED SHIPPING SCREW SCALE INDICATOR ZERO AND SPAN POTENTIOMETER ADJUSTMENT COVER HOLDING POSITION SCALE SET SCREW ZERO POTENTIOMETER ADJUSTMENT SHAFT SPRING WIRE DRY SPAN KNOB HOLDING POSITION (USE ONLY WHEN INSTALLING SHIPPING SCREW) POINTER VENT PLUG CALIBRATION DOOR SHIPPING SCREW CLIP CALIBRATION DOOR SCREW W5073-2/IL Figure 13. Calibration Adjustments CAUTION A3545-2/IL Figure 14. Transmitter Calibration Setup 4. Verify that plug P2 is in the correct position for direct or reverse action as appropriate (figure 7). 5. Loosen the screw on the zero and span potentiometer adjustment cover and turn the cover to expose the potentiometer adjustment shafts. 6. Turn the span potentiometer (marked S ) to its full counterclockwise position and then clockwise two full turns. The cam can be damaged if the dry span knob is rotated in the incorrect direction. Always rotate the dry span knob clockwise when moving away from the AUTO position. Rotate the dry span knob counterclockwise when moving toward the AUTO position. 7. Set the dry span scale in the center of its slip range as follows: a. Loosen the set screw in the dry span knob. b. Hold the dry span knob so that it can t rotate. c. With a free finger, slip the scale clockwise until it stops, then counterclockwise to the opposite stop, noting limits of travel. d. Position the scale so that it is midway between the two stops and hand tighten the set screw. Coupling 1. Turn the dry span knob to 0 percent using the appropriate right- or left-hand dry span scale. 12

13 2. Set the displacer to the lowest possible process condition, (i.e. lowest water level or minimum specific gravity, highest temperature) or replace the displacer by the heaviest calibration weight. Interface or density applications with displacer/torque tube sized for a small total change in specific gravity are designed to be operated with the displacer always submerged. In these applications, the torque rod is sometimes resting on a stop while the displacer is dry. The torque tube does not begin to move until a considerable amount of liquid has covered the displacer. In this case, it is necessary to couple with the displacer submerged in the fluid with the lowest density and the highest process temperature condition, or to an equivalent condition simulated with the calculated weights, 3. Move the spring wire to the R holding position. 4. Remove the vent plug and insert the hex nut driver into the hole and onto the torque tube shaft clamp nut. Tighten to a maximum torque of 18 lbf#in. (2.1 N#m). 5. Return the spring wire to its neutral (center) position. The spring wire must be in the neutral (center) position for operation in the automatic mode. 6. Turn the dry span knob to the AUTO position. 7. Use the zero potentiometer (marked Z ) to adjust the output current as follows:! For direct action: adjust the output current to 4 ma.! For reverse action: adjust the output current to 20 ma. 8. Determine the point where the cam touches the eccentric pin by slowly turning the dry span knob until the output current begins to move off the zero value. 9. If the resulting dry span scale reading is within!5 percent, go to step 19. If it is not, record the dry span scale reading and proceed with the next step. 10. Loosen the torque tube shaft clamp nut. 11. Move the spring wire to the R holding position. 12. Determine a new coupling position from the following: New coupling % = ( 1) (dry span scale reading in step 9) Example: X% = ( 1) ( 10) X% = +10 Example: X% = ( 1) (+7) X% = Move the dry span knob to the new coupling position. 14. Retighten the torque tube shaft clamp nut. 15. Return the spring wire to the neutral (center) position. The spring wire must be in the neutral (center) position for operation in the automatic mode. 16. Turn the dry span knob to the AUTO position. 17. Use the zero potentiometer (marked Z ) to adjust the output current as follows:! For direct action: adjust the output current to 4mA! For reverse action: adjust the output current to 20 ma 18. Slowly turn the dry span knob until the output current reading barely begins to move off the zero value. If the transmitter has been precalibrated for 4 to 20 ma output with reference to 0 to 100% on the dry span scale, (a stand alone transmitter is shipped in this condition), each dry span scale division indicates 1% of span. With this initial condition, the dry span knob may be rotated till the output current is 1% of span (0.16 ma) inside the current range limit, then align the scale at the 1% mark. 13

14 19. Loosen the scale set screw. Firmly hold onto the dry span knob while turning the scale. 20. Slip the scale to indicate 0 percent without moving the dry span knob. If you cannot get the scale to the appropriate mark, loosen the dry span knob set screw, re-center the scale, hand tighten the set screw, and return to step 9). 21. Hand Tighten the scale set screw. 22. Return the dry span knob to the AUTO position. Zero and Span Adjustment 1. Depending on the transmitter action, perform one or the other of the following:! For direct action: move the displacer to the lowest position (i.e., lowest water level or minimum specific gravity, highest process temperature) or replace the displacer by the heaviest calibration weight.! For Reverse Action: move the displacer to the desired highest position (i.e., highest water level or maximum specific gravity, lowest process temperature) or replace the displacer by the lightest calibration weight. 2. Adjust the output current to 4 ma with the zero potentiometer. 3. Depending on the transmitter action, perform one or the other of the following:! For Direct Action: move the displacer to the highest position (i.e., highest water level or maximum specific gravity, lowest process temperature) or replace the displacer by the lightest calibration weight.! For Reverse Action: move the displacer to the lowest position (i.e., lowest water level or minimum specific gravity, highest process temperature) or replace the displacer by the heaviest calibration weight. 4. Adjust the output current to 20 ma with the span potentiometer. 5. Repeat steps 1 and 3 to verify calibration and trim values if necessary. Recording the Sensor Span 1. To record the sensor output span on the dry span scale, first move the spring wire to the R holding position. 2. Turn the dry span knob until the current output is 20 ma for direct action or 4 ma for reverse action. 3. Mark this position on the scale with a felt tip pen and record the scale reading of the mark on a calibration sticker inside the dry span door. (This marked span position is used later in calibrating to specific application requirements). 4. Turn the dry span knob counterclockwise to the AUTO position. 5. Move the spring wire to the neutral (center) position. Securing the Unit for Shipment or Placing the Unit In Service 1. If the system is to be moved without blocking the displacer before being placed in service (as in skid mounted systems), perform the following: a. Uncouple the transmitter from the torque tube and install the shipping screw. (The spring wire may be hooked in the L position to facilitate engaging the shipping screw in the lever assembly threads.) b. Tag the calibration door with the appropriate warning and indicate that the transmitter will need to be re-coupled before placing in service. (When re-coupling, the dry span scale mark will still be correct after the zero is aligned with the dry displacer condition.) 2. If the system is being placed in service, or is being moved with the displacer blocked, the shipping screw should be stored in the holding clip inside the door. 3. Close the calibration door and tighten the door screw. 4. Turn the zero and span potentiometer adjustment cover back over the potentiometer adjustment screws and tighten the cover screw. Determining Suspended Weight for Calibration CAUTION To avoid overloading a torque tube sized for interface or density applications under dry conditions, consult your Fisher sales office or sales representative for the maximum allowable substitute weight W s that can be used with your particular construction. To determine the total weight that must be suspended from the displacer rod to simulate a certain condition 14

15 of process temperature, fluid level or specific gravity, solve the following equation: where: W s " Wd # $%# w &(V s )(SG)'( W s! [1 # $(%T)] = Total suspended weight in pounds (kilograms) [should never be less than 0.5 lbs (0.227 kg)]. For liquid level control at standard temperature and pressure only, simulate the lower range limit of the input span by hanging the displacer on the displacer rod. For other values of process temperature or input span, remove the displacer and suspend the appropriate weight as determined in the equation above. $ = (% change in torque tube modulus per "F ("C))/100% (Ref. TM-18 or call engineering) %T = (Expected process temperature) (temperature of torque tube during calibration), in "F ("C) W d = Weight of the displacer, in pounds (kilograms) [determine by weighing displacer]. : for top-mounted sensors, also include the weight of the displacer stem. & w = Density of water (specific gravity = 1.0), pounds per cubic inch (9.992 x 10 4 kilograms per cubic centimeter) V s = Volume of the displacer, in cubic inches (cubic centimeters), that would be submerged at the level required by the calibration procedure. '(/4 (displacer diameter) 2 x (length of displacer submerged)] SG = Specific gravity of the process fluid at operating temperature. For interface level measurement, the equation becomes: W s! " W d # %# w &(V)[(h l )(SG l ) ) (h h )(SG h )]( [1 # $(%T)] where: V = Volume of the displacer, in cubic inches (cubic centimeters). '(/4 (displacer diameter) 2 x (length of displacer submerged)] h l = Relative length of displacer that is immersed in the lighter fluid. [(length of the displacer immersed in lighter fluid)/(length of the displacer)] SG l = Specific gravity of the lighter fluid at operating temperature. h h = Relative length of displacer that is immersed in the heavier fluid. [(length of the displacer immersed in heavier fluid)/(length of the displacer)] SG h = Specific gravity of the heavier fluid at operating temperature. Dry Calibration The appropriate Matching the Transmitter to a 249 Series Sensor procedure must have been completed, and its sensitivity recorded, before performing this procedure. All locations referenced in this procedure are shown in figure 13 unless otherwise indicated. A transmitter factory-mounted on a sensor is already matched and does not require the matching procedure. The matching is performed at room temperature using water with a specific gravity of 1 or with appropriate weights. The scale is marked at full actual travel (span) and will be the larger value on the appropriate scale. If other conditions are used in matching, they should be indicated on a calibration sticker inside the dry span door, If such is the case, the following procedure will not be applicable without modification 1. Loosen the screw on the calibration door and open the door. 2. If the red shipping screw is installed (clamping the lever assembly) in the housing wall, remove it and stow it in the clip on the door. The transmitter is most likely uncoupled from the torque tube. In this case, perform the Coupling steps of the Matching the Transmitter to a 249 Series Sensor procedure before pro- 15

16 ceeding. To confirm that the unit is coupled, observe that the spring wire moves as the displacer is lifted Place the shipping screw in the clip provided in the calibration door for reinstallation after completing the calibration procedures if the unit is to be moved. 3. Connect the transmitter to the test equipment per the calibration setup (figure 14) and turn on the power supply and the DVM. 4. Move the spring wire to the R holding position. 5. Loosen the screw on the zero and span potentiometer adjustment cover plate and turn the cover plate to expose the adjustments. The span control pivots the output transfer characteristic around the 4 ma output point. For this reason, the 4 ma output point is adjusted first with the zero control, for both direct and reverse action. 6. Steps 7 through 12 of this procedure are broken into two parts, one for level applications and one for interface level or density measurement. Perform one or the other of steps 7 through 12 depending upon the application Dry Calibration for Level Applications (Steps 7 through 12) 7. Determine the calculated dry span scale setting (PB process ) required for 100% level calibration point by using the following formula: where: PB process = (SG process ) x (PB water ) SG process = specific gravity of process fluid PB water = recorded or marked dry span scale value from the wet calibration procedure (equivalent to the mechanical proportional band of the torque tube when using water at ambient conditions as the process fluid) 8. Depending on the transmitter action, perform one or the other of the following:! For direct action, turn the dry span knob to 0 percent on the appropriate scale.! For reverse action, turn the dry span knob to the calculated 100% scale setting on the appropriate scale. 9. Adjust the zero potentiometer until the output current is 4 ma. 10. Depending on the transmitter action, perform one or the other of the following:! For direct action, turn the dry span knob to the calculated 100% scale setting on the appropriate scale.! For reverse action, turn the dry span knob to 0 percent on the appropriate scale. 11. Adjust the span potentiometer until the output current is 20 ma. 12. Proceed to step 13. Dry Calibration for Interface Level or Density Measurement Applications (Steps 7 through 12) 7. If the transmitter was initially coupled at dry displacer condition and marked with SG = 1.0, compute the 0% and 100% dry span scale settings for the dry span scale as follows: where: 0% scale setting = (SG min ) x (PB water ) 100% scale setting = (SG max ) x (PB water ) SG min = lowest specific gravity for density or specific gravity of top phase for interface. SG max = highest specific gravity for density or specific gravity of bottom phase for interface PB water = recorded or marked dry span scale value from the wet calibration procedure (equivalent to the mechanical proportional band of the torque tube when using water at ambient conditions as the process fluid) 16

17 Normal factory matching procedure is done with a specific gravity of 1.0. If a specific gravity other than 1.0 was used in the factory matching procedure, or the transmitter was coupled at other than dry displacer condition, the zero and span settings for the dry span scale and the associated SG values are shown on a label (key 171) on the inside surface of the calibration door. In this case, use the values on the label to confirm the calibration, rather than the formula shown above. The rated accuracy of the dry span scale is only 2.5% of 4.4 degrees and the resolution is about 1% of 4.4 degrees, so its usefulness is limited at low proportional band settings. 8. Depending on the transmitter action, perform one or the other of the following:! For direct action, turn the dry span knob to 0% on the appropriate scale.! For reverse action, turn the dry span knob to the calculated 100% scale setting on the appropriate scale. 9. Adjust the zero potentiometer until the output current is 4 ma. 10. Depending on the transmitter action, perform one or the other of the following:! For direct action, turn the dry span knob to the calculated 100% scale setting on the appropriate scale.! For reverse action, turn the dry span knob to 0% on the appropriate scale. 11. Adjust the span potentiometer until the output current is 20 ma. 12. Proceed to step 13. Dry Calibration Continued (Steps 13 through 17) 13. Move the spring wire to the neutral (center) position. The spring wire must be in the neutral (center) position for operation in the automatic mode. 14. Turn the dry span scale to the AUTO position. W1389-1*/IL TORQUE TUBE DISPLACER 249 SERIES (SIDE VIEW) Figure 15. Typical Sensor Operation 15. Remove the test equipment. 16. Close the calibration door and tighten the door screw. 17. Turn the zero and span potentiometer adjustment cover back over the adjustment shafts and tighten the machine screw. Principle of Operation A level, density, or interface level change in the measured fluid causes a change in the displacer position (figure 15). This change is transferred to the torque tube assembly. As the measured fluid changes, the torque tube assembly rotates up to 4.4 degrees for a 249 Series sensor, varying the transmitter output between 4 and 20 ma. This conversion is described in the following paragraphs and shown in the block diagram (figure 16). The rotary motion is transferred to the transmitter lever assembly (via a bellows) supported by flexure strips. The rotary motion moves a magnet attached to the lever assembly, changing the magnetic field that is sensed by the Hall-effect position sensor. The sensor then converts the magnetic field signal to an electronic signal. The electronic signal is ambient-temperature-compensated and amplified by the differential amplifier. The signal is then linearized to compensate for the nonlinearity of the magnetic field. The first and second-order 17

18 SK588 B1842-1/IL Figure 16. Block Diagram of Type 2390 and 2390B Transmitter Operation low pass filters dampen the effects of process turbulence and prevent saturation of the dc amplifier and the current driver. The dc amplifier provides noninteracting zero and span adjustments. The current driver circuit develops a 4 to 20 ma current output signal proportional to the dc amplifier voltage output. The voltage regulator provides stable supply voltages for the transmitter circuits under varying operating conditions. Circuits within the transmitter provide reverse polarity protection, transient power surge protection, and electromagnetic interference (EMI) protection. Maintenance WARNING To avoid personal injury due to fire or explosion, remove electrical power before removing the transmitter in a hazardous area. Do not apply power to the transmitter, with the covers removed, while in a hazardous area. Troubleshooting Prior to reading the following text, go through the calibration section and check the items as described in the Precalibration Considerations procedure. An improperly set up transmitter can be the source of the problem. If recalibrating does not clear up the problem, proceed with this section. Key numbers are shown in figure 21 or 22 unless otherwise indicated. 1. Isolate the problem to the sensor or transmitter. Set up the transmitter as if to do the calibration procedure shown in figure 14. Then slowly move the displacer up and down by changing the liquid level. The output should follow the change in liquid level. 2. If there is no change in output in step 1, open the calibration door (key 4) and carefully observe the movement of the spring wire on the lever assembly (figure 9) while changing the liquid level. If movement cannot be detected: a. Remove the vent plug (figure 9) and loosen the shaft clamp (figure 9) on the lever assembly (key 12) with the hex nut driver inserted through the vent plug hole. b. Manually move the spring wire (figure 13) up and down and observe the output. If there is no output or an abnormal output is observed the malfunction is in the transmitter. Further troubleshooting of the transmitter can be done by following table 4 and figure 17, or the transmitter can be returned to the factory for repair. If a 0 to 100 percent output can be obtained by moving the spring wire, the transmitter is functional and the problem lies with either the torque tube shaft coupling or the displacer of the sensor. Consult the appropriate Type 249 sensor instruction manual for further instructions on the sensor. 18

19 3N10061-G/IL Figure 17. Schematic Diagram of Type 2390 and 2390B 4 to 20 ma Transmitter 19

20 Table 4. Troubleshooting Guide Symptom Possible Cause Check Corrective Action 1. No output Incorrectly wired Wiring Wire correctly 2. Output is below 3.2 ma dc Incorrect supply voltage or excessive field wiring resistance 3. Output is constant at 3.2 or 30 ma dc 4. Lever assembly magnet movement across Hall sensor does not change output signal 5. Output drifting or erratic on bench at constant temperature Sensor assembly failure Sensor assembly failure Open zero or span potentiometer or wiring harness Sensor assembly failure Printed wiring board failure Printed wiring board failure or sensor failure Voltage at field terminals should be between 11 and 45 volts dc Sensor assembly by performing the Checking Transmitter Sensor Assembly procedure Sensor assembly by performing the Checking Transmitter Sensor Assembly procedure Confirm resistance for zero and span potentiometers (20K ohms), continuity, solder joints, and connector crimps of harness Sensor assembly by performing the Checking Transmitter Sensor Assembly procedure Sensor assembly checks OK and magnet has not been demagnetized. Replace parts successively to isolate problem Check power supply voltage and total field wiring resistance against figure 3. Replace sensor assembly Replace sensor assembly Replace potentiometers or repair wiring harness Replace sensor assembly Replace printed wiring board Replace faulty part After any disconnection or troubleshooting, recalibrate the transmitter using the Matching the Transmitter to a 249 Series Sensor procedure before putting it back into operation. 7. Observe the output of the sensor on the DVM while slowly rotating the dry span knob from 0 to 100 percent on the R scale. The DVM reading should be proportional to rotation, as follows: Checking Transmitter Hall-Effect Sensor Assembly Key numbers are shown in figure 21 or 22 unless otherwise indicated. 1. Remove the printed wiring board housing cover (key 2) from the transmitter. 2. Remove the analog output meter (key 16), if installed, as described in the Removing the Analog Output meter procedure. 3. Apply +24 volts dc to transmitter (via field wiring). 4. Disconnect the Hall-effect sensor assembly plug P2 (figure 7) from the printed wiring board and connect it to the DVM [+ to yellow (pin 1) and to green (pin 2)]. 5. Center the dry span scale in its slip range per step 7 of the Matching the Transmitter to a 249 Series Sensor, Setup procedure. 6. Move the spring wire to the R holding position (figure 13). +47!8 mv at the 0% extreme 0!7 mv at the 50% position, and 47!8 mv at the 100% position 8. If the output does not change with rotation, the sensor assembly is not functioning properly. Proceed to step If the output varies but is not within the above specifications, the lever assembly may be damaged or out of alignment. Inspect the lever assembly for damaged or loose flexures, failed bonds on bellows joints, magnet damage, etc. Make any required repairs, or replace with a lever assembly that is known to be in good condition. Perform the Reinstalling the Lever Assembly procedure in the Maintenance section of this manual. Then repeat the troubleshooting tests. If the output is still not within specification, proceed to step 10. If the output is within specification, proceed to step Turn the power supply off and measure the resistance between pins 1 and 2 of the sensor output plug P2. If the reading is not between 900 and 1200 ohms, replace the sensor assembly (key 11). If the resistance is within specification, proceed to step Disconnect plug P1 (figure 7) from the printed wiring board and measure between its pins (blue and red wires). If the reading is not between 900 and

21 ohms, replace the sensor assembly. If the resistance is within specifications, proceed to step Connect a milliammeter between pins 1(+) and 2( ) on the printed wiring board connector J Turn the power supply on. 14. The current should be between 2.08 and 2.12 ma at 70"F (21"C). [If measured at 40"F ( 40"C), the current should be approximately 0.05 ma lower than the 70"F (21"C) value. At +176"F (80"C), the current should be approximately 0.05 ma higher than the 70"F (21"C) value.] 15. If the current meets specification but the sensor output is not within the ranges given in step 7 for 100% span (4.4 degree rotation of the input shaft), the sensor assembly sensitivity is non-standard and it must be replaced. 16. To replace the sensor, see Removing the Printed Wiring Board Assembly and Removing and Re-Installing the Transmitter Sensor Assembly. Checking the Analog Output Meter The analog output meter resistance should be approximately 3.5 ohms. Removing the Transmitter from a 249 Series Sensor CAUTION Take special care during removal of the transmitter from the 249 Series sensor. Bending or side-loading of the sensor torque tube assembly could cause errors in measurement on re-installation. 249 Series Sensor in Standard Temperature Application Key numbers are referenced in figure 21 or 22 except where otherwise indicated. 1. Remove the vent plug (figure 9) and loosen the shaft clamp (figure 9) on the lever assembly (key 12) with the hex nut driver inserted through the vent plug hole. 2. Turn the dry span scale to the auto position and move the spring wire to the L position to make reinstalling the shipping screw easier. 3. Re-install the red shipping screw (key 57) that was removed in the Installation or Calibration section. 4. Loosen and remove the hex nuts (key 62) from the mounting studs (key 61). 5. Carefully pull the transmitter straight off the sensor torque tube. 6. When re-installing the transmitter, follow the appropriate procedure outlined in the Installation section. 249 Series Sensor in High Temperature Application Key numbers are shown in figure 10 except where otherwise indicated. 1. Remove the vent plug (figure 9) and loosen the shaft clamp (figure 9) on the lever assembly (key 12, figure 21 or 22) with the hex nut driver inserted through the vent plug hole. 2. Turn the dry span scale to the auto position and move the spring wire to the L position to make reinstalling the shipping screw easier. 3. Re-install the red shipping screw (key 57, figure 21 or 22) that was removed in the Installation or Calibration section. 4. Loosen and remove the cap screws (key 39). 5. Carefully pull the transmitter straight off the torque tube shaft or torque tube shaft extension (key 37). 6. Loosen and remove the hex nuts (key 62, figure 21 or 22) from the mounting studs (key 61, figure 21 or 22). 7. Pull the heat insulator (key 35) off the mounting studs. 8. When re-installing the transmitter, follow the appropriate procedure outlined in the Installation section. 21

22 Printed Wiring Board Compartment Parts Removal and Replacement CAUTION Electrostatic voltages present in the field environment and transferred to the printed wiring board can cause failure or degraded performance. Use appropriate antistatic procedures any time the printed wiring board housing cover is removed. Key numbers are shown in figure 21 or 22 except where otherwise indicated. Removing the Analog Output Meter 1. Disconnect power. 2. Unscrew and remove the printed wiring board housing cover (key 222). 3. Unscrew the two machine screws (key 18). 4. Disconnect connector plug P5 from board connection J5 (figure 7). 5. Remove the entire output meter assembly (key 16) from the housing (key 1). Removing the Printed Wiring Board Assembly 1. Disconnect connector plugs P1, P2, P3, P4, P6, and P7 from board connections J1, J2 or J2.1, J3, J4, J6, and J7 respectively (figure 7). 2. Remove the three machine screws (key 20). 3. Carefully remove the printed wiring board (key 64) from the housing (key 1). Removing a Potentiometer Assembly 1. Loosen the hex nut on the potentiometer assembly until the threads are disengaged. 2. Pull the potentiometer (key 27 or 28) and shaft coupling (key 25) slowly and carefully off of the potentiometer shaft extension (key 22) with a twisting motion. Removing and Re-installing the Transmitter Hall-Effect Sensor Assembly 1. Remove the two machine screws (key 167). 2. Slide the sensor assembly (key 11) out of the housing (key 1). 3. To re-install, slide the O-ring (key 10) over the sensor assembly. 4. Slide the Hall-effect sensor assembly into the housing. 5. Insert the two screws (key 167) and alternately tighten. Re-installing a Potentiometer Assembly 1. The potentiometer assembly comes with the shaft coupling (key 25) installed on the potentiometer (key 27 or 28). Slip the shaft coupling (key 25) over the potentiometer shaft extension (key 22). 2. Unscrew the hex nut on the potentiometer bushing until it is near the end of the bushing. Insert the potentiometer assembly (keys 27 or 28) into the bracket and snugly tighten the hex nut. Re-installing a Printed Wiring Board Assembly CAUTION To avoid damaging wiring that can interrupt transmitter operation when the analog output meter and printed wiring board are installed, verify that wires are routed around the posts and through the notch in the printed wiring board as shown in figure Route the Hall-effect sensor wires as shown in figure Insert the printed wiring board assembly (key 64) into the housing (key 1). 3. Tighten the three machine screws (key 21). 4. Reconnect connector plugs P1, P2, P3, P4, P6, and P7 to board connections J1, J2 or J2.l, J3, J4, J6, and J7 respectively as identified in figure 7. Re-installing the Analog Output Meter CAUTION To avoid damaging wiring that can interrupt transmitter operation, verify that 22

23 AMPLIFIER PWB WIRES MUST NOT CROSS THIS EDGE OF SENSOR FLANGE TO PREVENT CUTTING WHEN METER IS INSTALLED ANALOG METER LOCATION POST 2. Remove the two funnel plate machine screws (key 19) and funnel plate (key 45). 3. Loosen and remove the red shipping screw (key 57) if installed. RED & BLUE WIRES 17B0679-A / DOC Figure 18. Hall-Effect Sensor Wire Routing GREEN & YELLOW WIRES SENSOR ASSEMBLY Place the shipping screw in the clip provided on the calibration door for reinstallation after completing the calibration procedures if the unit is to be moved. 4. Loosen and remove the two cap screws (key 20). wires are not pinched between the output meter assembly and the printed wiring board when installing the output meter. A notch in the meter hole is provided for wires to pass through the printed wiring board. 1. Insert the output meter assembly (key 16) into the hole in the printed wiring board (key 64). 2. Connect connector plug P5 to the board connection J5 (figure 7). 3. Position the aperture (key 17) over the meter, insert the machine screws (key 18) through the aperature and output meter mounting holes and tighten snugly. 4. Screw the printed wiring board housing cover (key 222) snugly onto the housing (key 1). Sensor Connection Compartment Parts Removal and Re-installation Remove the transmitter from the 249 Series sensor as described in the Removing the Transmitter from a 249 Series Sensor procedure. Key numbers are shown in figure 21 or 22 except where otherwise indicated. Removing the Lever Assembly 1. Remove the nuts (key 62) and slide the adapter ring (key 3) off the housing and mounting studs (keys 1 and 61). 5. Pull the lever assembly (key 12) gently out of the housing. 6. Inspect the flexure strips (key 85, figure 23) to see if they are in any way bent or damaged. If they are damaged, replace as described in the following procedure. Removing and Replacing the Flexure Strips Key numbers are shown in figure 23 except where otherwise indicated. Remove the lever assembly as described in the previous procedure. 1. Position the alignment tool as shown in figure 19, step Insert the alignment tool guides into the holes on the bracket assembly as shown in figure 19, step While firmly grasping the alignment tool, remove the cap screws (key 89), washer plate (key 93), and the flexure strips (key 85) from the lever assembly. CAUTION Hold the alignment tool firmly when replacing flexure strips to prevent possible bending or stressing that could cause inaccurate operation. 4. Carefully position the new flexure strips and then insert the washers, plates and cap screws. Lightly snug the cap screws to hold the flexure strips in position. 23

24 FLEXURE STRIP FLEXURE STRIP CAP SCREWS WASHER STRIP ALIGNMENT TOOL NOTE: MAINTAIN CONSTANT PRESSURE ON ALIGNMENT TOOL AND LEVER ASSEMBLY DURING REMOVAL AND REINSTALLATION. W5605/IL STEP 1 ALIGNMENT TOOL POSITIONED STEP 2 ALIGNMENT TOOL IN PLACE Figure 19. Removing and Reinstalling Flexure Strips W5604/IL 5. Tighten the cap screws at the solid end of the flexure, then alternately tighten all the cap screws to 9 lbf#in (1 N#m). 6. Remove the alignment tool. Removing the Dry Span Scale Key numbers are shown in figure 21 or 22 except where otherwise indicated. 1. Loosen the door screw on the calibration door (figure 13) and open the door. 2. Loosen the scale set screw (figure 13) on the dry span knob with a screwdriver. 3. Put a 9/32 inch or a 7 mm wrench on the cam disk assembly shaft nut (key 46) and hold firmly. The scale can also be removed by inserting a small rod through the aligned hole in the dial and housing. 4. Turn the dry span knob counterclockwise and remove the knob, pointer, and scale (keys 50, 49, and 48) from the shaft. Re-installing the Dry Span Scale 1. Put the dry span scale over the shaft with the proper scale orientation (figure 20). 2. Put the pointer over the shaft and screw the knob clockwise loosely onto the cam disk assembly shaft. 3. Put a 9/32 inch (7 mm) wrench on the shaft nut and hold firmly. The scale can also be assembled by inserting a small rod through the aligned hole in the dial and housing. 4. Tighten the dry span knob. 5. Set the dry span scale to its middle position (figure 20) in reference to the scale adjustment stop. 6. Tighten the scale set screw on the dry span knob with a screwdriver. Re-installing the Lever Assembly Key numbers are shown in figure 21 or 22 except where otherwise indicated. 1. Insert the lever assembly (key 12) into its mounting position. 24

25 Type 2390 and 2390B W5602-1/IL PIN W5603-1/IL SPRING WIRE SCALE ADJUSTMENT STOP DUAL SCALE SHOWN WITH KNOB AND POINTER IN PLACE SPRING WIRE IS IN NEUTRAL (CENTER) POSITION CAM DUAL SCALE SHOWN WITH KNOB AND POINTER REMOVED Figure 20. Transmitter Dry Span Scale 2. Insert and tighten the two cap screws (key 20). 3. Carefully move the lever assembly back and forth over the sensor assembly (key 11). There should be no touching or restriction of free travel. 4. Connect the transmitter test equipment per the setup shown in figure 14 and turn on the power supply and DVM. 5. Measure the output from the unconnected A or B connector (figure 7). If the reading is 0 (zero)!13 mvdc, go to step 8. If the reading is not within the!13 mvdc limits, continue with the following step. The transmitter should be in the mounting position with the vent plug on the bottom. 6. Loosen the cap screws (key 20) slightly and insert an Allen wrench in the lever assembly adjustment hole. 7. Turn the wrench to move the lever assembly until the output is 0 (zero)!13 mvdc. Retighten the lever assembly mounting screws. 8. Move the spring wire to the R holding position (figure 20). 9. Loosen the scale set screw (figure 13) and slip the scale to its approximate middle position. The scale can be rotated approximately 7 dry span scale divisions from center in either direction. 10. Tighten the scale set screw. 11. Set the dry span scale to 50% on the scale. 12. Loosen the locking cap screw (key 92, figure 23) with a 5/64 inch (2 mm) Allen wrench. 13. Adjust the eccentric pin (key 91, figure 23) until the output voltage equals 0 (zero)!1 mvdc. 14. Tighten the locking cap screw (key 92, figure 23). 15. Return spring wire to the neutral (center) position. 25