Edwards SCU-801

SCU-801 Control Unit for Turbomolecular Pump
MT-95E-001-A
Page 122
8
MAINTENANCE
Referred
section
Instruction Manual
(B)
*1 The driver output stops and the rotor continues rotating by inertia.
It may take several hours to stop. To stop the STP pump
quickly, close the vacuum valve at the outlet port flange
and introduce gas from the purge port into the STP pump.
Table
37 - Error
messages after self test (continued)
Countermeasures
1. Contact Service office. 2. Contact
Service office.
1. Contact Service office. 2. Contact Service office.
1. Use the maximum working
pressure or less.
2. Use the allowable backing
pressure or less.
3. Check the vacuum piping
system for leakage.
4. Check the backing
-pump for
its capacity and START state. (use a backing
-pump with
the recommended capacity or more)
Contact Service office.
Contact Service office.
Contact Service office.
Contact Service office.
Probable causes
1. Wear
-out of the cooling
water bearing
.
2. Failure of the cooling fan
drive
circuit
.
1. Short of the STP
connection
cable.
2. STP pump failure.
1. High pressure at the inlet
port.
2. High pressure at the outlet
port.
3. Leakage of the piping
system.
4. Failure of the
backing
-pump.
Failure of the SCU
-801.
Failure of the SCU
-801.
Failure of the
SCU-801.
Failure of the SCU
-801.
Pump operation
Decelerate and stop
.
Free run
.
*1
Decelerate and stop.
Free run
.
*1
Free run
.
*1
Touch down. The magnetic bearing output stops and the rotor is descended on the
touch down
bearing.
Decelerate and stop.
Occurrence condition
Cooling fan come to a stop.
Driver over current.
ACCELERATION state continues for approximately 30
minutes.
Driver overvoltage.
Failure of the driver circuit
.
Abnormal CPU operation
.
Serial communication failure.
LCD Messages
Driver FAN Failure
Driver Overcurrent
Driver Overload
Driver Overvoltage
Driver PWM Trouble
DSP Initialize Fail
DSP->PCB Com Fail