Troubleshooting - Emerson Fisher FIELDVUE DVC2000 Instruction Manual

4. Pull the main electronics straight off of the
mounting frame. The board is electrically connected to
an interconnecting board with a rigid connector.
5. Remove the two screws holding the mounting
frame to the instrument housing (refer to figure 6-2).
6. Pull the mounting frame straight out. The
interconnecting board is electrically connected to the
termination board with a rigid connector.
7. Remove the two screws holding the pneumatic
relay to the mounting frame.
8. Pull the pneumatic relay straight out.
Assembly
When installing a new pneumatic relay, follow the
reverse procedure as outlined above and recalibrate
the instrument.

Troubleshooting

What is a healthy unit?
In order to troubleshoot the DVC2000 digital valve
controller, it is critical to understand how a healthy unit
is supposed to behave. Below is a list of behaviors you
should see if the instrument is performing well.
D LCD correctly displaying characters
D Pushbuttons allow navigation
D Valve travels full stroke
D No diagnostics messages
D No alerts or alarms
D Hall sensor within the valid range of travel on the
magnet array
D Slight audible air venting
D Minimal overshoot
D Quick response
D Functionality matches the tier level
July 2009
Maintenance and Troubleshooting
What are the observable symptoms?
The next thing to do is to identify the symptoms of the
unhealthy unit. Are there any obvious discrepancies
that can be identified? Work through the following
items to help gather information about the faulty
behavior and identify the core problem(s). Also see the
DVC2000 Troubleshooting Checklist on page 6-9.
1. Check the relay pressure range.
There are two available relays for the DVC2000:
D Low pressure: 0−3.4 bar (0−49 psi) — white label
D High pressure: 3.5−7 bar (50−100 psi) — green
label
The supply pressure feeding the instrument must fall
within the rated pressure range of the installed relay
for proper operation.
2. Check the instrument protection (LCD via
pushbuttons and Configure/Calibrate via HART)
3. Check for local device diagnostic messages
4. Check the alerts via HART
5. Check the feedback setup
Is the pole piece on the DVC2000 housing within the
valid travel range of the feedback array?
6. Observe the stem movement and pressure delivery
Determine the logical causes.
With the discrepancies identified, logic can now be
applied to isolate the component that is in need of
repair or replacement. There are seven main
categories of problems:
1. Wiring and Terminations
2. Air Supply
3. Electronics
4. Firmware
5. Pneumatics
6. Travel feedback
7. Mounting
Repair or replace the faulty components.
By isolating the problem to one of these categories,
component replacement or repair becomes simple and
straightforward. Refer to section 6 for component
replacement instructions.
6
6-7