VAT 642 Series - Page 82

TROUBLE SHOOTING Series
642
82/107 Edition 2017-11-24 813316EB
- Does sensor power supply
provide enough power for
sensor(s)?
- Verify sensor supply voltage.
ZERO does not work - Valve in open position, check
for O on display?
- OPEN VALVE and bring chamber to base pressure
before performing ZERO.
- ZERO disabled? - Enable ZERO.
Refer to «Valve and sensor configuration» for details.
Pressure is not ‘0’ after ZERO - Sensor voltage shifting? - Wait until sensor does not shift any more before
performing ZERO.
- System pumped to base
pressure?
- OPEN VALVE and bring chamber to base pressure
before performing ZERO.
- Sensor offset voltage
exceeds ±1.4V
- Replace pressure gauge.
PRESSURE CONTROL does not
work
- Safety mode active, check
for D on display?
- Provide power to motor to allow for operation.
- Refer to «Electrical connection» for details.
- PRESSURE CONTROL
selected, check for P on
display?
- Select PRESSURE CONTROL mode.
Refer to «Pressure control» for details.
- LEARN done? - Perform LEARN.
Refer to «Setup procedure» for details.
PRESSURE CONTROL not optimal - Setup done completely? - Perform «Setup procedure» completely.
- LEARN done? - Perform LEARN.
Refer to «LEARN» for details.
- ZERO performed before
LEARN?
- Perform ZERO then repeat LEARN.
Refer to «Setup procedure» for details.
- LEARN interrupted? - Repeat LEARN.
Refer to «LEARN» for details.
- Was gas flow stable during
LEARN?
- Repeat LEARN with stable gas flow.
Refer to «LEARN» for details.
- Tuning done? - Tune valve for application.
- Refer to «Tuning of control performance» for details.
- Is sensor range suited for
application?
- Use a sensor with suitable range (controlled pressure
should be >3% and < 98% of sensor full scale).
- Noise on sensor signal? - Make sure a shielded sensor cable is used.