Emerson FIELDVUEDVC2000 Instruction Manual
Contents
1. be overcome The switching valve must be calibrated to reset upon restoration of adequate supply pressure to the regulator The 377L trip valve has only one spring selection However for minimal deadband the lightest appropriate spring should be selected for the 164A switching valve Lock in Last Using Solenoid Valves Solenoid valves are used with valve assemblies in many ways Their electrical control can be utilized in combination with switches and controller logic to perform a number of functions Note Solenoid valves placed between the output of a DVC6000 or DVC6200 digital valve controller and the input to an actuator require a minimum of 0 49 Greater restrictions can affect the response of the assembly An example of an appropriate three way solenoid valve for use with the digital valve controller is the ASCO 8327 Series solenoid valve from ASCO Valve Inc Assemblies with Single Acting Actuators A three way universal solenoid valve can be placed between the digital valve controller output and the actuator input Switching the valve assembly from an unlocked state to a locked state is controlled by switching power on and off to the solenoid valve Figure 3 depicts proper assembly layout Under normal operating conditions the solenoid is energized and supply air flows from the digital valve controller output to the actuator input In the fail state power is removed from the solenoid causing the solenoid valve to close locking air2. pressure in the actuator Port 1 of the solenoid valve is plugged preventing actuator air pressure from exhausting to the atmosphere DVC6000 DVC6200 Digital Valve Controllers Instruction Manual Supplement February 2011 D103261X012 Figure 3 Lock in Last Strategy for an Assembly with a Single Acting Actuator Using a Solenoid Valve Fisher DVC6000 Depicted LI gt SOLENOID VALVE Pe 24 VDC ENERGIZED _ POWER SUPPLY FISHER 67CFR FILTER REGULATOR pamat O OUTPUT A AIR VALVE SUPPLY CONTROLLER a NOTE LD A SOLENOID VALVE WITH A MINIMUM Cy OF 0 49 SUCH AS THE ASCO 8327 SERIES OR EQUIVALENT IS REQUIRED FOR THIS ASSEMBLY Assemblies with Double Acting Actuators Assemblies with double acting actuators require a 377L trip valve to lock pressures on both sides of the actuator piston Figure 4 is a schematic of a double acting actuator with lock in last capability shown in its normal operating mode The solenoid valve is placed in series with the signal port of the trip valve When tripped the solenoid valve exhausts the signal pressure to the trip valve to atmosphere This simulates a loss in supply pressure causing the trip valve to lock pressure in the actuator Figure 4 Lock in Last for an Assembly with a Double Acting Actuator Using a Solenoid Valve Fisher DVC6000 Depicted SOLENOID VALVE lt 7 ENER
3. GIZED Peace 24 VDC SSS POWER SUPPLY FISHER 377L 1 2 TRIP VALVE ao 3 C FISHER 64 REGULATOR a Dama O SUTPUT L AR vave ce SUPPLY SUPPLY CONTROLLER O SUTPUT FISHER 252 AIR GAS FILTER NOTE gt THE ASCO 8320 SERIES SOLENOID VALVE OR EQUIVALENT IS APPROPRIATE FOR THIS ASSEMBLY Instruction Manual Supplement DVC6000 DVC6200 Digital Valve Controllers D103261X012 February 2011 The solenoid valve in this solution does not require a C greater than 0 49 Flow capacity of this valve can be much smaller An example of a proper solenoid valve for this assembly is the 8320 Series three way solenoid valve As with all solenoid valves ensure that the solenoid valve operating pressure differential rating is adequate for the supply pressure Lock in Last on Loss of Supply Pressure and or Loss of Loop Current Most applications require a valve assembly to be in a lock in last fail state not only on loss of adequate supply pressure but also on loss of loop power Lock in last on loss of supply pressure is quite straight forward Lock in last on loss of loop power can be more complex Most control loops operate on a 4 20 mA control signal A solenoid valve adequately sized for the application requires more than 4 mA to energize Therefore the control loop cannot be used to energize the solenoid Instead the solenoid must be powered by a s
4. Instruction Manual Supplement DVC6000 DVC6200 Digital Valve Controllers D103261X012 February 2011 Supplement to Fisher FIELDVUE DVC6000 or DVC6200 Digital Valve Controller Instruction Manuals Implementation of Lock in Last Strategy Many applications require a valve assembly to remain in the position it was prior to a specific control system failure lock in last position Functionality and safety can be designed into valve assemblies with FIELDVUE digital valve controllers by utilizing an array of accessories The following paragraphs describe standard solutions for a number of generic lock in last applications with DVC6000 or DVC6200 digital valve controllers Note This instruction manual supplement is for use with HART communicating FIELDVUE DVC6000 or DVC6200 digital valve controllers only Lock in Last on Loss of Supply Pressure Once the supply pressure falls below a minimum value the digital valve controller can no longer position a valve assembly the valve will start to go to the actuator at rest position The locking device senses this change and activates preventing the remaining air from venting The valve is locked in this new position Note The locked in valve position depends on the exhausting speed of the actuator Assemblies with Single Acting Actuators A Fisher 164A three way switching valve should be used for locking a single acting actuator in place on loss of supply pressure Figure 1 is a sche
5. eparate 24 volt power source Thus an additional device is required to monitor the current to the digital valve controller and control the power to the solenoid A current threshold switch can be used to monitor the 4 20 mA signal to the digital valve controller Upon loss of this signal or when the signal falls below the threshold the threshold switch will open an internal relay This relay if placed between a solenoid valve and its power supply will essentially open and close the solenoid valve The solenoid valve can be placed in line with the tubing to the actuator to provide the lock in last function To ensure adequate response time of a locking system to a loss of loop current a threshold switch with a maximum deadtime of 0 025 seconds should be used The locking system will be faster than the response of the positioning system to the failure One switch that meets the maximum deadtime requirements is the Phoenix Contact Dual Setpoint Module Model MCR 2SP UI Note The MCR 2SP UI switch is not provided by Emerson Process Management Order this switch from Phoenix Contact Assemblies with Single Acting Actuators Assemblies with a single acting actuator use a 164A three way switching valve in conjunction with a solenoid valve Figure 5 is aschematic of a single acting actuator assembly with lock in last capability on loss of supply pressure or loop current Under normal operating conditions power is supplied to the solenoid valve and adeq
6. he valve will travel toward its fail safe position A relay with an engagement deadtime such as the MCR 2SP UI from Phoenix Contact can be used to delay the release of the locking system until the digital valve controller has completely initialized An engagement delay of 1 0 seconds will adequately minimize the dip in travel Note While the valve is in a locked state the set point from the digital valve controller may change in response to changes in process conditions This change in set point may result in a process bump when control is restored to the digital valve controller Related Documents e Fisher FIELDVUE DVC6000 Digital Valve Controllers Instruction Manual D102794X012 e Fisher FIELDVUE DVC6000 Digital Valve Controllers Quick Start Guide D102762X012 e Fisher FIELDVUE DVC6200 Digital Valve Controller Instruction Manual D103409X012 e Fisher FIELDVUE DVC6200 Digital Valve Controller Quick Start Guide D103410X012 These documents are available from your Emerson Process Management sales office Also visit our website at www FlELDVUE com DVC6000 DVC6200 Digital Valve Controllers Instruction Manual Supplement February 2011 D103261X012 Phoenix Threshold Switch Specifications Switch Model Number Connect switch in series between the solenoid valve MCR 2SP UI DC and 24 VDC power supply Power Supply to switch terminal 12 Size Power Supply to switch terminal 13 44 5 X 76 2 X 108 mm 1 3 4 X 3 x 4 1 4 inches Configurat
7. ion Mounting Set point 1 15 3 mA Mounts in control room DIN rail mount Engagement Deadtime 1 second Wiring Switch Settings Connect switch in series between control loop and Switch Setting Description field device 1 On SP 1 Control Loop to switch terminal 2 on si Control Loop to switch terminal 1 4 On In 24 VDC Power Supply to switch connections 5 off Out 1 6 off Out 2 Power Supply to switch terminal 8 7 off Hys 1 Power Supply to switch terminal 7 8 off Hys 2 1 The Phoenix threshold switch is not uppie by Emerson Process Management Order the switch from the manufacturer Phoenix Contact www phoenixcontact com For complete installation details see the instruction manual provided by the switch manufacturer Note Neither Emerson Emerson Process Management nor any of their affiliated entities assumes responsibility for the selection use or maintenance of any product Responsibility for the selection use and maintenance of any product remains with the purchaser and end user Fisher and FIELDVUE are marks owned by one of the companies in the Emerson Process Management business division of Emerson Electric Co Emerson Process Management Emerson and the Emerson logo are trademarks and service marks of Emerson Electric Co HART is a mark owned by the HART Communication Foundation All other marks are the property of their respective owners The contents of this publication are presented for informat
8. ional purposes only and while every effort has been made to ensure their accuracy they are not to be construed as warranties or guarantees express or implied regarding the products or services described herein or their use or applicability All sales are governed by our terms and conditions which are available upon request We reserve the right to modify or improve the designs or specifications of such products at any time without notice Neither Emerson Emerson Process Management nor any of their affiliated entities assumes responsibility for the selection use or maintenance of any product Responsibility for proper selection use and maintenance of any product remains solely with the purchaser and end user Emerson Process Management Marshalltown lowa 50158 USA Sorocaba 18087 Brazil r Chatham Kent ME4 4QZ UK Dubai United Arab Emirates gt Singapore 128461 Singapore www Fisher com EMERSON Process Management Fisher Controls International LLC 2006 2011 All Rights Reserved
9. lve so long as power is maintained to the AO card Assemblies with Double Acting Actuators The same principle used for assemblies with single acting actuators is used for assemblies with double acting actuators Figure 6 is a schematic of the double acting assembly with lock in last capability shown under normal operating conditions Instruction Manual Supplement DVC6000 DVC6200 Digital Valve Controllers D103261X012 February 2011 Figure 6 Lock in Last on Loss of Loop Current and or Supply ressure for an Assembly with a Double Acting Actuator Fisher DVC6000 Depicted E 3 24VDC POWER SUPPLY ro 1278 420mA PHOENIX SWITCH mcr 2sPjul 13 SOLENOID VALVE C ENERGIZED FISHER 377L TRIP VALVE 1 2 DA 3 EB legl AIR SUPPLY Les FISHER 64 pee ee REGULATOR o parat SfoutPuT H VALVE SUPPLY T CONTROLLERO OUTPUT FISHER 252 AIR GAS FILTER NOTE CT THE ASCO 8320 SERIES SOLENOID VALVE OR EQUIVALENT IS APPROPRIATE FOR THIS ASSEMBLY Note DVC6000 and DVC6200 digital valve controllers require approximately 0 5 seconds to initialize upon power up During this time the digital valve controller cannot provide control In the case where control of a previously locked valve is restored to a digital valve controller prior to the completion of initialization t
10. matic representing proper assembly layout In normal operation the digital valve controller output passes through the switching valve from port A to port B and on to the actuator EMERSON Jr mer www Fisher com Process Vianagement DVC6000 DVC6200 Digital Valve Controllers Instruction Manual Supplement February 2011 D103261X012 Figure 1 Lock in Last on Loss of Supply Pressure for an Assembly with a Single Acting Actuator Fisher DVC6000 Depicted FISHER 164A THREE WAY SWITCHING VALVE 2 oara OT OUTPUT A AIR vave OF SUPPLY SUPPLY CONTROLLER FISHER 67CFR FILTER REGULATOR In a fail condition the pressure at port D is below the switching valve s set point causing the switching valve to trip This closes port B which locks the pressure in the actuator Port C is plugged so the digital valve controller output will not exhaust to the atmosphere Assemblies with Double Acting Actuators Similar to the locking strategy used with single acting actuators the locking strategy with double acting actuators also uses a valve for locking supply pressure in the actuator For assemblies with double acting actuators a Fisher 377L trip valve is used as the locking device The 377L trip valve has two output ports for locking pressure on both sides of a double acting actuator Figure 2 is a schematic representing proper assembly layout Figure 2 Lock in Last on Loss of Supply Pressure for a
11. n Assembly with a Double Acting Actuator Fisher DVC6000 Depicted FISHER 377L TRIP VALVE INPUT DA EB FC Lt FISHER 64 REGULATOR DIGITAL O OUTPUT vave OL SUPPLY CONTROLLER O SUTPUT 4 AIR T SUPPLY Instruction Manual Supplement DVC6000 DVC6200 Digital Valve Controllers D103261X012 February 2011 Connection of the digital valve controller output to a double acting actuator determines the action of the actuator Figure 2 shows the digital valve controller providing lower cylinder pressure through ports D and E and upper cylinder pressure through ports A and B When the supply pressure falls below the set point of the trip valve the trip valve closes ports D and A and connects port B to C and port E to F Because C and F are plugged the control valve is locked in place by locking pressure on both sides of the actuator piston The assembly returns to normal operation once supply pressure is restored at the trip valve INPUT port Note Double acting actuators with a 377L trip valve require a Fisher 64 or 95H regulator Regulators with smaller flow capacities may cause the trip valve to cycle lock and unlock repeatedly due to air flow demand as the assembly attempts to reset Use a Fisher 252 or 262C pilot filter to filter supply air Both the 164A switching valve and the 377L trip valve have a deadband that must
12. uate supply pressure is available to the switching valve Upon loss of supply pressure the set point of the switching valve is exceeded and the switching valve trips DVC6000 DVC6200 Digital Valve Controllers February 2011 Instruction Manual Supplement D103261X012 Figure 5 Lock in Last on Loss of Loop Current and or Supply Pressure for an Assembly with a Single Acting Actuator Fisher DVC6000 Dep icted FISHER 164A THR SWITCHING VALVE EE WAY C gt SOLENOID VALVE ENERGIZED PHOENIX SwitcH 12 1 fe as FISHER 67CFR gt FILTER REGULATOR piataL O OUTPUT 4 VALVE SUPPLY AIR CONTROLLER O a SUPPLY MCR 2SP UI 13 24VDC POWER SUPPLY NOTE gt THE ASCO 8320 SERIES SOLENOID VALVE OR EQUIVALENT IS APPROPRIATE FOR THIS ASSEMBLY Upon loss of loop current the relay of the current threshold switch opens This cuts power to the solenoid valve causing the solenoid valve to trip When the solenoid valve trips the supply pressure that was holding the switching valve open is exhausted to atmosphere This simulates a loss of supply pressure causing the switching valve to trip Note Use a single power source for both the analog output AO card providing loop current to the digital valve controller and the solenoid valve This ensures power will be maintained to the solenoid va
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