Choosing, calibrating, and mounting remanufactured Fisher® DVC positioners is a relatively straightforward process. Here, we’re going to discuss the differences between DVC6000 and DVC6200 positioners and how to get them up and running.
If you still have questions after reading through this guide, don’t hesitate to call us at (800) 325-4808.
DVC6000 vs. DVC6200: Which one is right for your application?
Before you dig too deep into the difference between DVC positioners, identify if you need one at all. For example, if you have a 4-20mA input, you might not need a DVC — a 3582i or 3620j positioner could be a solution. On the flipside, you will need a DVC if it needs to be HART®.
After deciding a DVC is right for you, consider the difference between the DVC6000 and DVC6200: linkage. The prior has a mechanical linkage, and the latter has a magnetic linkage. Since the DVC6000 has a mechanical linkage, it’s not suitable for all applications. For example, if you use a DVC6000 in a high-vibration environment, you run the risk of getting more variance in readings as well putting more wear and tear on the linkage.
Here are some guidelines for when you should choose the DVC6200 instead.
- If you have high vibration issues
- If you already have a mounting kit in place for a DVC6200
- If you require I/O Expansion (you’ll need a DVC6200 with position feedback)
Note: Advanced Diagnostics are the same on both models.
Mounting instructions
DVC6000
Once your DVC6000 has arrived, you’re ready to mount the device. These instructions will walk you through how to mount the device onto a sliding stem valve. Use these easy-to-follow steps or the video below as a guide to get the job done.
You’ll be working with four main components: the adjustment arm, a connector arm, lock nut, and a star washer. Set the nut on the connector arm hand tight to get it in a good starting
position.
- Begin by threading one of the two mounting bolts through the mounting bracket into the yoke so you can hang the bracket to help you get the positioner lined up. As you slide the DVC6000 into position, the connector arm needs to stay on top of the bias spring attached to the feedback arm. Line the positioner up, threading the other bolt through the mounting bracket into the yoke. Then, tighten both bolts.
- The next step is to get the travel adjusted. Start by retrieving the alignment pin from inside the cover. Access the alignment pin by loosening the four captivated screws and removing the cover.
- Use the alignment pin to hold the feedback arm in position as you adjust for its travel. Using ¾” travel as an example, adjust the feedback arm to line up with the connector arm shaft at the .75” mark. And at the same time, align hole A with the alignment pin to the threaded hole in the housing.
- Once you have the feedback arm adjusted, firmly hold the connector arm while you tighten the nut on the connector arm to maintain its position.
- Return the alignment pin to its retaining hole in the module base, put cover back
on, and tighten the captivated screws. - Next, connect your DVC output to the actuator.
- After that, apply supply pressure and move on to setup wizard and then travel calibration.
DVC6200
Here are the instructions for mounting a DVC6200. Again, follow the instructions below or reference the video to see the process in action.
- The first step in the process is attaching the mounting bracket to the yoke of the actuator.
- Then, loosely attach the feedback pieces, including the magnet assembly, to the valve stem. Don’t over tighten them, because you’ll need to make some fine adjustments later on.
- In the next step, use the alignment template supplied with your mounting kit to position your magnet assembly. The style of actuator you are using will determine how you should align the magnet assembly.
- Air to open actuator — Line the magnet up so the center line of the template is aligned as close as possible with the upper extreme of the valid travel range.
- Air to close actuator — Align the center line template as closely as possible with the lower extreme of the valid travel range.
- Next, tighten the fasteners and remove the alignment template.
- Mount the DVC to the mounting bracket using the mounting bolts and adjust for proper clearance between the magnet assembly and the 6200 back slot.
Calibration instructions
After mounting your remanufactured DVC, you’ll need to calibrate the device. Before you begin calibration, verify if current source is analog or digital (DCS) and set appropriately. Then follow the steps below to get your instrument up and running.
DVC6000
On receiving a DVC6000, the instrument mode is “In Service.”
- This Mode needs to be changed to “Out of Service” during configuration
- Communicator Path: Setup and Diag/Detailed Setup/ Instrument Mode
- Take out of service
- Next step is to teach positioner the equipment it is working with
- Communicator Path: Setup and Diag/Basic Setup/ Setup Wizard
- Upon selecting you will be prompted by communicator to input several pieces of information: MFG, Actuator Type & Size, Supply Pressure, etc.
- It will prompt for factory default – choose YES.
- After info is entered communicator will prompt you to enter Travel Calibration
- Will ask Auto- or Manual- control – Auto is suggested
- After choosing Auto it will ask you for Crossover Adjustment Source to define the midpoint – select Manual.
- During Auto Calibration valve will open fully and close multiple times while searching for its end points.
- You will be asked to define a midpoint (crossover) – Adjust input current as needed (near 12 mA) until feedback arm is perpendicular to the adjustment arm.
- Select “Continue” with Auto Travel Calibration.
- Once Auto Travel Calibration is complete
- Communicator will prompt you to put back in service – choose “In Service”.
- Adjust current source from 4-20 mA and note valve position.
- Linear? Verify functionality.
- Non-linear? Needs further adjustment.
- If DVC fails Auto Travel Calibration:
- Check travel sensor adjustment – see related section of manual.
- Verify I/P functioning properly – is I/P Linear?
- Verify pressures on output pressure and supply gauges.
- If DVC passes Auto Travel Calibration, but is unsteady or oscillates:
- Adjust response control – dampening.
- Communicator Path: Setup and Diag/Detailed Setup/Response Control/Tuning Set
- A letter was assigned during setup to factory default – choose a lower letter – move a couple steps lower at a time, may need to repeat until control smooths out.
Note: Different device descriptions and DVC styles may have slightly different terminology. Path give is based on 375 or 475 communicator structure.
Click here to download a PDF of these calibration instructions.
DVC6200
On receiving a DVC6200, the instrument mode is “In Service.”
- Hook up a HART® communicator to the DVC6200 in parallel with a 4-20 mA loop across the “loop” terminals
- Apply a 4 mA signal to the DVC and power up the HART communicator
- First, put the instrument in “not in service” mode. Do this by entering the menu ‘configure’, then ‘detailed setup’, then ‘mode and protection’, then ‘instrument mode’
- Choose “not in service” and press enter
- Hit the home key to return to the main menu
- Now enter ‘configure’, then ‘guided setup’, then ‘setup wizard’
- Entering ‘setup wizard’ will start you through configuration prompts asking for information about the actuator and valve you are working with
- Enter the actuator manufacturer, type, size, and supply pressure requirements as requested by the communicator
- When asked, go ahead and send the factory defaults to begin with (fine tuning can be adjusted later)
- After completing the setup wizard portion, the communicator will prompt you to start the auto-travel calibration portion
- When asked for adjustment method for output bias choose manual
- The communicator will automatically stroke the valve to 100% travel and 0% travel and adjust the output bias
- When it asks for 50%, adjust the mA input to 12 mA and proceed with the remainder of the auto-travel calibration procedure
- Afterwards, the communicator will prompt you to return it to “in service” mode; do so
- Stroke the valve completely and make sure your valve opens linear to your 4-20 mA input signal
Note: Different device descriptions and DVC styles may have slightly different terminology. Path give is based on 375 or 475 communicator structure.
Click here to download a PDF of these calibration instructions.
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Resource links
- DVC6000 Calibration Instructions [PDF]
- How to Mount a Fisher DVC6000 on Sliding Stem Valve [Video]
- DVC6200 Calibration Instructions [PDF]
- Two Cent Tech Tip Mounting a DVC6200 [Video]
- Troubleshooting a DVC in a Digital Control System [Video]
Still have questions? Contact us at (314) 665-1741 and our team will help you every step of the way. Our engineers are always available for assistance by email, phone, and chat.
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