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Instruction Manual

D103425X012

546NS Transducer

June 2021

22

Figure 8. Torque Motor Assembly

30A8594‐K
B1767‐3

    APPLY LUBRICANT/SEALANT

NOTES:
1. SHADED KEY NUMBERS INDICATE PARTS THAT 
SHOULD 

NOT

 BE DISASSEMBLED FROM TORQUE MOTOR.

2. KEY NUMBERS 22 AND 103 ARE NOT SHOWN.

Key

Description

 51

(1)

Bottom Pole Piece Plate

 52

(1)

Travel Stop

 53

(1)

Terminal Mounting Bracket Ass'y

 55

(1)

Span Adjustment Ass'y

(2)

 56

Bellows Screw

 57*

Bellows Ass'y
 Full Size, 21 mm (27/32 inch) O.D.
 Half Size, 13 mm (1/2 inch) O.D.
 Quarter Size, 9.5 mm (3/8 inch) O.D.

Key

Description

 58

Tubing Ass'y

 94

Anti‐seize sealant
 (not furnished with unit)

 96

Silicone‐based lubricant, medium grade
 (not furnished with unit)

103

Set Screw (not shown)

105

(1)

Spacer

*Recommended spare parts

1. Parts are not field repairable. The torque motor assembly should never be

disassembled because the magnetism in the torque motor will decrease

permanently. Shaded key numbers shown in figure 8 indicate parts that should not
be disassembled.

2. The span adjustment assembly uses a bronze passive lock, rather than nylon, and
a locking hex nut.

Summary of Contents for Fisher 546NS

Page 1: ...Replacement 16 Replacing the Feedback Bellows Assembly 17 Troubleshooting 17 Electrical 17 Pneumatic 17 Alignment 18 Span Adjustment 18 Torque Motor Frame 19 Armature Travel Stop 19 Coil 19 Figure 1 Fisher 546NS Electro Pneumatic Transducer Mounted on a 657 Pneumatic Diaphragm Actuator W2115 546NS FILTER REGULATOR Parts Ordering 20 Repair Kits 20 Parts List 20 Transducer 20 Torque Motor 21 Relay 2...

Page 2: ...erally a control valve is pneumatically operated The input signal output pressure range and electrical classification if approved of each transducer is indicated on the nameplate attached to the cover The 546NS transducer is designed for nuclear power applications The 546NS construction includes materials that provide superior performance in elevated temperature and radiation environments The O ri...

Page 3: ...ural frequencies found between 5 100 Hz and seismic dwells of 8g uniaxial from 3 40 Hz when mounted using Fisher specified seismic mounting brackets D LOCA MSLB Event Simulation saturated steam for 14 hours at 160_C 320_F followed by a gradual reduction to 83_C 182_F over a 10 hour period Upon conclusion of the above tests no loss of function or visible degradation was found Educational Services F...

Page 4: ... 4 bar 20 psig Supply Pressure 12 9 normal m3 hr 480 scfh At 2 4 bar 35 psig Supply Pressure 18 5 normal m3 hr 690 scfh Performance 3 Actuator Loading Time See figure 6 Reference Accuracy 4 0 75 of the output span Independent Linearity 0 50 of the output span Open Loop Gain 26 Frequency Response Gain is attenuated 3 dB at 20 Hz with transducer output signal piped to a typical instrument bellows wi...

Page 5: ...rmance values are obtained using a 546 transducer with a 4 to 20 mA DC input signal and a 0 2 to 1 bar 3 to 15 psig or a 0 4 to 2 bar 6 to 30 psig output signal Ambient temperature is 24_C 73_F A transducer with other input or output signals might exceed these values Reference accuracies of 3 5 can be expected with output ranges starting near zero psig 4 Reference accuracy includes the effects of ...

Page 6: ... and may override the standard installation procedures Special instructions are listed by approval Note This information supplements the nameplate markings affixed to the product Always refer to the nameplate itself to identify the appropriate certification Contact your Emerson sales office for approval certification information not listed here CSA and FM No special conditions of safe use Refer to...

Page 7: ...r method of air filtration or filter maintenance Note The supply source must be clean dry oil free non corrosive air at an unfailing pressure at least 0 3 bar 5 psig higher than the upper limit of the transducer output pressure range This means that for an output pressure range of 0 2 to 1 0 bar 3 to 15 psig the supply pressure should be at least 1 4 bar 20 psig for a 0 4 to 2 0 bar 6 to 30 psig r...

Page 8: ...stalled Select wiring and or cable glands that are rated for the environment of use such as hazardous area ingress protection and temperature Failure to use properly rated wiring and or cable glands can result in personal injury or property damage from fire or explosion Wiring connections must be in accordance with local regional and national codes for any given hazardous are approval Failure to f...

Page 9: ...lied to the transducer with the cover removed in a hazardous area If the transducer is installed in an application where explosion proof classification is required perform the following steps prior to removal of the transducer cover when any procedure in this section requires removal of the cover D Disconnect the electrical signal from the transducer D Remove the transducer to a non hazardous area...

Page 10: ...ld start at 3 psig and increase to 1 0 bar 15 psig as the input signal is changed from 4 to 20 mA DC A span adjustment will affect the zero Therefore follow any span adjustment with a zero adjustment Provide a suitable gauge to measure the pressure CAUTION If the transducer is not used as specified in this instruction manual the protection provided by the equipment may be impaired Calibration Equi...

Page 11: ...0 20 and 1 00 bar 3 00 and 15 00 psig This allows for error at other calibration points in between 7 Run the transducer through three calibration cycles before recording data The cycles should be run from exactly 4 00 to 20 00 mA DC in a slow ramping fashion no large step inputs Note Large step inputs during calibration can result in an inaccurate reflection of the actual state of calibration Use ...

Page 12: ... replacement may correct the problem Refer to the alignment procedures in the Troubleshooting section to correct the operation of a faulty transducer Also check for air leaks at the tubing nozzle relay and bellows If the accuracy error is greater than 5 percent of output span check the clearance between the armature and the coils These parts are referenced as key 40 and key 42 respectively in the ...

Page 13: ... on only one half of the normal input span the feedback bellows must be changed to compensate for the shorter span Change the bellows as described in the replacing feedback bellows assembly procedure in the Maintenance section Table 6 indicates which bellows is required for your conditions Reset the span and zero adjustments to the split range values Note that these transducers cannot provide a th...

Page 14: ...ibrium position In this way the new nozzle pressure is compared to the input current by the force balance principle The relay operates in the following manner The nozzle pressure acts on the large top diaphragm to force the center spacer assembly mounted between the two diaphragms downward against the valve plug closing the exhaust port and opening the supply port Supply air then flows through the...

Page 15: ... require that the transducer be taken out of service This requires that certain precautions be taken to avoid personal injury or equipment damage caused by sudden release of pressure Prior to maintenance D Always wear protective clothing gloves and eyewear when performing any maintenance procedures to avoid personal injury D Disconnect electrical power before removing the transducer cover D Shut o...

Page 16: ...rrect some problems Improper supply pressure and mechanical defects in pneumatic and electrical connections should be apparent upon inspection and repaired as appropriate CAUTION Never disassemble the torque motor assembly because the magnetism in the torque motor magnets will decrease permanently Shaded key numbers indicate parts that should not be disassembled from the torque motor see figure 8 ...

Page 17: ... transducer circuit to see that it coincides with the value listed on the circuit identification tag located on the torque motor 4 Check the terminal lugs for proper connections If reverse action of the transducer is observed simply reverse the input leads as indicated in the Reversing the Action procedures in the Operating Information section Pneumatic CAUTION Do not attempt to remove the nozzle ...

Page 18: ...ards for use with corrosive air or if you are unsure about the proper amount or method of air filtration or filter maintenance 9 Check the nozzle for residue Air supply must be clean and dry Use air filter to remove dirt and oil 10 Check the pneumatic connection of the transducer to prevent leakage Alignment The following alignment procedures can be used in conjunction with troubleshooting procedu...

Page 19: ... to over travel The clearance between the armature and travel stop should be 0 13 mm 0 005 inches The two screws at the base of the travel stop can be loosened if an alignment is necessary Coil The coil assembly key 42 figure 8 consists of a nylon bobbin wound with wire The coils are not attached to the armature itself and therefore they must not touch the armature or armature movements will be re...

Page 20: ...scription Part Number Transducer Repair Kit Kit includes keys 6 12 36 37 and 58 R546X000032 82 Relay Replacement Assembly Assembly includes two mounting screws key 68 10A8593X132 Parts List see figure 7 Note Contact your Emerson sales office for Part Ordering information Key Description Transducer 1 Transducer Case Ass y 2 Case Cover Key Description 3 Protective Plug 4 Tagging Plate optional 5 Nam...

Page 21: ...Wire Ass y 22 1 Hook Up Wire not shown 25 1 Machine Screw 26 1 Screw 27 1 Cap Screw Key Description 28 1 Machine Screw 29 1 O Ring 31 Hex Nut 32 1 Washer 33 Washer 34 1 Washer 35 1 Washer 36 O Ring 2 req d 37 O Ring 38 1 E Ring 40 1 Armature 41 1 Coil Support 42 1 Coil Ass y 48 1 Magnet 49 1 Pole Piece 50 1 Top Pole Piece Plate Recommended spare parts 1 Parts are not field repairable The torque mo...

Page 22: ...l Size 21 mm 27 32 inch O D Half Size 13 mm 1 2 inch O D Quarter Size 9 5 mm 3 8 inch O D Key Description 58 Tubing Ass y 94 Anti seize sealant not furnished with unit 96 Silicone based lubricant medium grade not furnished with unit 103 Set Screw not shown 105 1 Spacer Recommended spare parts 1 Parts are not field repairable The torque motor assembly should never be disassembled because the magnet...

Page 23: ...021 23 Figure 9 Fisher 82 Relay Assembly A1504 1 NOTE KEY 76 IS NOT SHOWN APPLY LUBRICANT SEALANT RESTRICTION HOLES Relay figure 9 Note The 546NS relay is not repairable If the relay is defective order the 82 Relay Replacement Assembly refer to Parts Kits ...

Page 24: ...s SST fittings Brass fittings For units without gauges SST fittings Brass fittings Emerson Automation Solutions Marshalltown Iowa 50158 USA Sorocaba 18087 Brazil Cernay 68700 France Dubai United Arab Emirates Singapore 128461 Singapore www Fisher com The contents of this publication are presented for informational purposes only and while every effort has been made to ensure their accuracy they are...

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