Mechanical Connections; Pump Location; Rotation Of The Pump Inlet With Respect To The Motor Frame; Pump Inlet - Varian TriScroll 300 Serie Manual De Instalación Y Funcionamiento

Mechanical Connections

Pump Location

Locate the pump on a firm, level surface.
Mounting holes provided in the frame can be used to
provide permanent attachment. The rubber mounts on
the frame can be removed if desired.
Rotation of the Pump Inlet
with Respect to the Motor Frame
The standard pump configuration is with the inlet fitting
positioned at the top of the pump as shown in Figure 1 on
page 34. The pump inlet has two alternate positions:
❑
90 degrees clockwise
❑
90 degrees counterclockwise
To rotate the inlet:
1. Remove three (3) M5 screws (item 1 on Figure 3 on
page 35) that secure the cowling (item 2 on Figure 3)
to the scroll module. Remove the cowling.
2. Tilt the pump back so that the rear end of the motor
touches the floor.
3. Remove the four (4) M6 screws (item 8 on Figure 3)
holding the frame (item 7 on Figure 3) and scroll
module together.
4. Axially separate the frame and scroll module.
5. Rotate the module 90 degrees in either direction and
realign the two (2) locating pins on the scroll module
with the mating frame holes. Ensure that the rubber
spider is still on the motor coupling and that the
coupling teeth are properly aligned.
6. Rejoin the scroll module with the frame and install
and tighten the four (4) M6 screws removed in step 3.
7. Reinstall the cowling using the three (3) M5 screws
removed in step 1.

Pump Inlet

Use NW25, or larger, clean vacuum hardware with as
short a length as practical between the pump and the
vacuum chamber.
Use a bellows to provide both vibration isolation and
strain relief between the pump and the vacuum chamber.

Pump Exhaust

A female 1/4" National Pipe Thread exhaust fitting is
located underneath the scroll module. This fitting swivels
360 degrees. Additionally, an NW16 male adapter with
1/4" National Pipe Thread is provided.
To avoid overheating the pump, do not restrict the
exhaust flow with long lengths of small diameter tubing.
Use as short as practical lengths of NW16 diameter, or
larger, hardware.
38
TriScroll 300 Series Vacuum Pump

Optional Isolation Valve

Scroll pumps return to atmospheric pressure quickly
when shut off, thus the installation of a fast acting,
automatic, normally closed isolation valve is strongly
recommended to prevent pump debris from being
transported back into the vacuum chamber when the
pump is turned off.
❑
The opening of this valve should occur
simultaneously with or after pump start up.
❑
Valve closing should occur before,
simultaneously with, but no later than 250 ms
after pump shut off.
Use an NW25 valve or larger and mount it as close as
possible to the pump inlet. Mounting to the pump inlet is
ideal. (See Figure 6).
.
Figure 6 Isolation Valve Location
Varian offers a variety of manual, electromagnetic and
electropneumatic controlled vacuum valves for vacuum
applications. The Varian Vacuum Pump Isolation (VPI)
Valve is highly recommended for vacuum pump isolation
applications. The VPI valve application and installation
information for use with TriScroll vacuum pumps has
been included below.
Varian also sells the TriScroll 300 pump with the VPI
valve preinstalled. The part number is PTS03001UVPI.
Overview
The status of the VPI Valve is controlled by the TriScroll
motor internal thermal switch and its electrical supply.
The VPI Valve opens when the pump is running and
closes when it is stopped. It will also close when the
TriScroll motor thermal overload protection switch shuts
down the pump.
CAUTION To prevent damage to the VPI Valve, it
must be installed by a qualified electri-
cian and only as specified below.