Edwards SCU-350 Series

SCU-350 Series Control Unit for Turbomolecular Pump
MT-21E-201-E
Page 78
6
MAINTENANCE
6.1.8 Overspeed
When the rotational speed of the STP pump exceeds the specified rotational value due to a failure in
the motor driver, the MAIN POWER on the SCU-350 switches "OFF". The STP pump has no power
supplied, decelerates and stops.
The "FAILURE" LED illuminates and the LCD displays error message "OVERSPEED" or "DRIVER
RA".
6.1.9 Error Messages
When an abnormality occurs, the "FAILURE" LED illuminates and the LCD displays an error message.
If an ampersand "&" is shown at the right of the error message, it indicates that more than one error
occurs. In this case, press the "SELECT" switch to display another error message.
(The "SELECT" switch can also be used during remote operation.)
Example:
A. Press "SELECT" switch
6.1.10 Troubleshooting immediately after power failure occurs
It is recommended to establish a procedure so that the power can be supplied to the SCU-350
immediately after a power recovery.
POWER FAILURE &
DISTURBANCE &
A
A