Aalborg PWE Digital - Manual (Page 76)

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8. TROUBLESHOOTING
8.1 Common Conditions
Your PWE Flow Meter was thoroughly checked at numerous quality control points
during and after manufacturing and assembly operations. It was calibrated accord-
ing to your desired flow and pressure conditions for a given fluid. It was carefully
packed to prevent damage during shipment. Should you feel that
the instrument is not functioning properly, please check for the following common
conditions first:
Are all cables connected correctly? Are there any leaks in the installation? Is the
power supply correctly selected according to requirements? When several meters
are used a power supply with appropriate current rating should be selected. Were
the connector pinouts matched properly? When interchanging with other
manufacturers' equipment, cables and connectors must be carefully wired for cor-
rect pin configurations. Is the pressure differential across the instrument suffi-
cient?
No INDICATION LIKELY REASON SOLUTION
1 LCD Display remains blank
when unit is powered up.
No response when flow is
introduced from analog
outputs 0-5 Vdc or 4-20
mA. Power supply is bad or
polarity is reversed. Measure voltage on pins A and B
of the 12 pin M16 connector. If
voltage is out of specified range,
then replace power supply with a
new one. If polarity is reversed
(reading is negative) make correct
connection.
PC board is defective. Return PWE to factory for repair.
2 LCD Display reading or
/and flow analog output 0-
5Vdc signal fluctuate in
wide range during flow
measurement. Flow output 0-5 Vdc signal
(pin L of the 12 pin M16 con-
nector) is shorted on the GND
or overloaded. Check external connections to pin
L of the 12 pin M16 connector.
Make sure the load resistance of
the equipment connected to the
flow 0-5 Vdc output is more than
1000 Ohm.
3 LCD Display reading or
/and temperature analog
output 0-5Vdc signal fluc-
tuate in wide range during
flow measurement. Temperature output 0-5 Vdc
signal (pin M of the 12 pin
M16 connector) is shorted on
the GND or overloaded. Check external connections to pin
M of the 12 pin M16 connector.
Make sure the load resistance of
the equipment connected to the
flow 0-5 Vdc output is more than
1000 Ohm.
4 LCD Display reading does
correspond to the correct
flow range, but 0-5 Vdc
output signal does not
change (always the same
reading or around zero). Output 0-5Vdc schematic is
burned out or damaged. Return PWE to factory for repair.
Analog flow output scale and
offset variable are corrupted. Restore original EEPROM scale and
offset variable or perform analog
output recalibration (see section
5.2).