Edwards SCU-1601

SCU-1601 Control Unit for Turbomolecular Pump
MT-96E-1B1-0
Page 69
4
OPERATION
Table 15 shows pump status in the state of speed selection.
Pump status
Difference between
Normal Speed and
Standby Speed Setting
is more than
approximately 10%
When the rotational speed becomes low, the STP pump enters
BRAKE mode, and then decelerates.
When the rotational speed becomes high, the STP pump enters
ACCEL mode, and then accelerates.
The STP pump will enter the normal mode when the rotational speed
attains within +10% of speed setting.
NORMAL
BRAKE
ACCEL
NORMAL
NORMAL
Pump status
Speed Set Point
Second Speed Set Point
Second Speed Set Point -10%
Second Speed Set Point +10%
Speed Set Point +10%
Speed Set Point -10%
Second speed select
OFF
ON
OFF
Rotational speed
Difference between
Normal Speed and
Standby Speed Setting
is approximately 10%
or less
The rotational speed changes in the normal mode.
NORMAL
Pump status
Speed Set Point
Second Speed Set Point
Second Speed Set Point -10%
Second Speed Set Point +10%
Speed Set Point +10%
Speed Set Point -10%
Second speed select
OFF
ON
OFF
Rotational speed
Table 15 - Second speed function