Edwards SCU-801

SCU-801 Control Unit for Turbomolecular Pump
MT-95E-001-A
Page 128
8
MAINTENANCE
8.6 When error message is not displayed on LCD
When the "FAILURE" LED illuminates and the LCD displays an error message, refer to Table 35 to
Table 42.
8.6.1 Abnormalities when powering ON
No.
Symptom
Probable cause
Countermeasures
Referred section
1
The "POWER"
LED does not
illuminate.
Incorrect connection of
power cable.
Connect the power cable
correctly.
3.6.3
Abnormal power
voltage.
Set the voltage to rated
voltage±10%.
2.1
3.6.3
Power failure.
Check if a power failure has
occurred.
8.1.1
Table 43 - Troubleshooting when powering ON
8.6.2 Abnormalities when performing rotational operation
No.
Symptom
Probable causes
Countermeasures
Referred section
1
The "ACCEL."
LED does not
illuminate.
The "MANUAL/
REMOTE"
changeover switch is
not in the correct
position.
Slide the "MANUAL/ REMOTE"
changeover switch to the correct
position.
3.2
4.4
4.5
Rotation INHIBIT
signal input pins
(REMOTE X7 (1)-(5))
are open.
When not using this function,
short the circuit between (1)-(5),
or set "Inhibit Command" to
"DISABLE".
If these pins are open, the STP
pump will not rotate after
performing the start operation.
4.5.1
3.11
Table 44 - Troubleshooting when performing the STP pump start operation