Maintenance – Yokogawa digitalYEWFLO (DY) User Manual
Page 78
IM 1F2B4-01-YIA
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MAINTENANCE
program values. If the amplifier has been reconfigured to accommodate new process conditions or
the programming sheet is not available, it will be necessary to generate a new sheet by running the
YEWFLO sizing program. Contact your Yokogawa Industrial Automation representative for a copy
of the sizing program.
Note:
For the remote amplifier, terminals A, B & C should be shorted together; otherwise, electrical noise
may interfere.
4.5.1
General amplifier check-out
a.
Access parameter H06 (NOISE JUDGE) and set to “NOT ACTIVE”.
b.
Access parameter G02 (SPAN FREQUENCY) and record this value. Attach a calibrated
frequency generator to test points TP2 and COM2 and inject the same frequency as read in
parameter G02.
c.
Access parameter G01 (FREQUENCY) and confirm that this value agrees with the
frequency in Step b above to within ±0.1%. Agreement of these two values confirms the
general internal operation of the amplifier. Any discrepancy in these two values indicates a
problem with the amplifier which may require amplifier replacement. Contact the Yokogawa
Industrial Automation Service Department for assistance at 1-800-524-7378.
d.
If you wish to stop here, disconnect the frequency generator, return parameter H06 to
“ACTIVE”. Otherwise, leave the frequency generator connected and parameters H06 and
any correction functions deactivated and proceed to the next section to confirm amplifier
calibration.
4.5.2
Analog output test
Before beginning this section, perform the amplifier checkout procedure, steps 4.5.1a - d above.
a.
Check the PULSE/ANALOG jumpers on the front of the amplifier to be sure they are in the
correct position. Access (analog) parameter B02 (OUTPUT) and confirm the setting agrees
with the jumper position.
b.
With the frequency generator connected and injecting the frequency per Step 4.5.1b measure
the current being produced by the amplifier. The output should be 20 mA, ±.02 mA.
c.
Remove the frequency generator and replace it with a shorting jumper and measure the
output. The output should be 4 mA, ±.02 mA.
d.
If there is a discrepancy in the outputs measured in steps b and c, contact the Yokogawa
Industrial Automation Service Department for assistance at 1-800-524-7378. Otherwise,
remove the jumper, return parameter H06 to “ACTIVE”. Analog testing is complete.