Ulvac UTM2300 Series, Instruction Manual

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SECTION 9 TROUBLESHOOTING
70
9
9.1
Vacuum Pressure Rise
A rapid rise of vacuum pressure in the turbo molecular pump causes the internal motor of the
turbo molecular pump to start braking and the STATUS orange lamp lights.
Do not suddenly increase the pressure or let atmospheric air enter the pump during pump
operation.
9.2
Abnormal Noise and/or Vibration
Should the turbo molecular pump ever generate abnormal noise and/or vibration, the turbo
molecular pump operation is to be stopped immediately.
But there is possible that a race of touch-down bearing (Fig. 3-1 (8)) may make sounds for
seconds when the pump internal pressure gets back to atmospheric pressure using air (or non-
activity gas). This phenomena is not abnormal and make no damage to the pump, because the
air whirlpool sometimes occurs and then makes the touch-down bearing rotate slightly.
NOTICE
When turning the POWER switch ON or OFF, a "clunk" sound may be heard from inside the
pump. This sound is from the rotor inside the pump being levitated or de-levitated. This is normal.