Agilent Technologies TV 551 Navigator, User Manual

Page: 266 / 328

17 Technical Information
Description of the TV 551/701 Navigator
266/328 TV 551/701 Navigator User Manual / 87-900-934-01 (P)
The static blades of the stator are made of stain-less steel. These are supported
and accurately po-sitioned by spacer rings.
The Macrotorr stators are in the form of self-positioning machined discs with
pumping channels and an opening restricted by the corresponding rotor discs.
These are made of aluminium alloy.
During normal operation, the motor is fed with a voltage of 54 Vac three-phase
at 715 Hz. To re-duce losses during start-up to a minimum, the fre-quency
increases according to a ramp with a higher initial voltage/frequency ratio.
The pump can be water cooled or air cooled: in the first case the customer can
use the dedicated channels on the pump body, in the second case an external
optional fan is available.
A thermistor sensor is mounted near the upper bearing to prevent the pump
from overheating.
The pump is balanced after assembly with a resid-ual vibration amplitude less
than 0.01 µm.
The pump can operate in any position and can be supported on the high
vacuum flange. The connection of the forevacuum on the side of the pump is a
KF 25 NW flange.
Figure 10