Startup and Troubleshooting
Page 39
August 2019
DPP-UM-00256-EN-03
Troubleshooting
Symptom
Cause/Oesolution
Display does not light up
• Insufficient power to monitor Measure voltage at J2
• Power supply not properly wired to J2 See
“Power Supply Wiring Connections” on page 21
• Fuse F1 is open or not installed
• Power supply jumpers are not installed properly See
“Power Supply Wiring Connections” on page 21
• Ribbon cable between the door and enclosure back is not fully engaged into the two sockets
EOOOO on the
DFX flow meter display
• Transducers not properly coupled to the pipe Couplant is not present or pipe not properly prepared
• Transducer not properly wired to the J4 Terminal block inside the meter Review the Wiring Diagram
on the inside door of the DFX meter
• More than one DFX meter is installed on the piping system
See
“Multiple Meter Installations” on page 23
• Insufficient particles over 35 microns Inject air upstream of the transducers
• Too many particles that are smaller than 35 micron prevent ultrasonic meters from operating
• Transducer failure Unplug transducer cable from J4, measure capacitance between blue/clear or red/
black Receive and Transmit Verify that the capacitance on each set is approximately 2 nF (nano Farads)
and within 0 02 nF of each other
Unstable flow reading
• Relocate transducer to a pipe position with less hydraulic disturbance
• Increase Damping value
• Ensure that ground connection is properly connected to meters earth ground See
Inaccurate flow reading
• Verify that pipe ID is entered correctly
• Verify that an erroneous Scale Factor has not been entered
• Verify that erroneous Linearization values have not been entered
• Verify that AGC is set to Normal
• Verify that the transducers are mounted square and 180 degrees apart on the pipe
• Relocate transducer to a pipe position with greater straight run length
• DP7 Probe not aligned in the pipe
Analog output does not match
data collection
system
• Verify 4…20 mA calibration
• Verify 4 mA and 20 mA flow settings Verify that the loop load is within the supply voltage range
• Run 4…20mA TEST feature to verify that mA outputs coincide with expected data collection
system readings
Oate Pulse output does not
match data collection system
• Verify 0 Hz and MAX Hz flow settings
• Place oscilloscope or frequency counter on the Rate Pulse module outputs and verify
frequency output
• Run output TEST feature to verify that the Hz output coincides with expected data collection
system readings
• Verify that the K-factor has been calculated correctly:
K-factor = Hz/(flow/second)
Example:
Max Hz (2500 Hz) = 10,000 Gallons/Minute
K-factor = 2,500 Hz / 166 7 Gallons/Second
K-factor = 15 pulses/gallon
• Verify that the data collection system is accepting the pulses from the meter Connect to Turbine OUT
or OUT/IN as required
DFX flow meter does not
capture short flow pulses
When run in AUTO mode, the meter uses a series of filters that optimize readings for a particular flow
range The flow meter takes several seconds to adjust to a step change in flow To make the flow meter
respond quickly to changes in flow, decrease DAMPING, place the meter into MANUAL AGC and lock the
FILTER at NONE
