Edwards nEXT730 - Maintenance; Bearing Maintenance

B8J200880_E - Maintenance
Page 103
WARNING:
When removing the pump, ensure personal protective equipment is used to
safeguard against damage from failed components and possible accumulation of
hazardous material that may have been pumped. Check that the pump is vented to
atmosphere and at a safe temperature. Be wary of possible spillages, sharp edges
and debris. Removal of the pump inlet screen will always expose the risk of injury
from sharp edges.
8. Maintenance
Table 23 Maintenance
Bearing maintenance on page
103
The bearing must be replaced when it reaches the end of its
service life. This is typically after 35,000 hours.
Rotor life on page 104
The fatigue life of nEXT Turbomolecular pump rotors is typically
40,000 to 50,000 cycles. As a precautionary measure, Edwards
recommends that pumps are returned for a major service (rotor re-
placement) after 20,000 cycles of acceleration to full speed and
back to a stop, or after ten years of use, whichever occurs first.
Cleaning the pump on page 104
If the inside of the pump is contaminated, it may not be possible to
achieve the specified ultimate vacuum performance, or pump-
down times may increase.
Decoding service status words on
page 104
The service status may be accessed directly via the serial link. This
method of accessing service status will give the most complete
picture of current and future service requirements and will allow
preventative maintenance activities to be scheduled.
Controller run time on page 106
The run hours and recommended service time of the controller on
the nEXT pump can be monitored.
Pump run time on page 106
The run hours and recommended service time of the rotor in the
nEXT pump can be monitored.
Pump cycles on page 106
The number of start-stop cycles completed and the number
remaining until the next service is due can be monitored.
Bearing run time on page 107
The run hours and recommended service time of the bearing in the
nEXT pump can be monitored.
8.1 Bearing maintenance
The bearing must be replaced when it reaches the end of its service life. This is typically
after 35,000 hours.
When the bearing needs replacing, Edwards recommends:
WARNING:
Allow the pump rotor to stop and then disconnect the motor controller before you
remove the pump from your vacuum system for maintenance or fault finding
procedures.