Varian HS452, Instruction Manual

Page: 21 / 45

TECHNICAL INFORMATION
SECTION II
CONNECTION TO THE ELECTRIC SUPPLY
CAUTION
It is recommended to connect the pump to the
power supply through a dedicated switch on the
main electrical panel of the installation, or in prox-
imity of the power supply connection point.
CONNECTIONS TO THE INLET AND EXHAUST
FLANGES
Remove the protective caps from both flanges.
Connect the system to be evacuated to the inlet
flange, using a centering ring with OR and a lock-
ing collar.
NOTE
For guaranteed reliable sealing, use an OR gasket
in Perbunan or Viton.
The inlet duct is equipped with a sieve filter pre-
venting solid particles from entering and damaging
the pump.
NOTE
When the gases to be pumped out contain dust, it
is advisable to insert a dust filter before the inlet
flange.
NOTE
When the gases to be pumped out contain large
quantities of vapor, it is advisable to include a
condense separator before the inlet flange.
To make best use of the pump’s capacity, use only
short, straight piping, with a diameter not smaller
than that of the inlet flange.
NOTE
If rigid piping is used, it is good practice to use a
flexible joint in order to avoid undue forcing of the
connection on the pump.
The exhaust duct must be connected to a pipe that
will take away the pumped out gases.
NOTE
Application of an oil trap filter is necessary to avoid
pollution of the surrounding atmosphere by the oil
present in the exhaust duct during pump opera-
tion.
CAUTION
Never block the pump exhaust line. This would
cause overpressure in the casing with the risk of
breaking the pumping block envelope.
STARTING AND RUNNING THE PUMP
Before being put into service, in order to reach
maximum vacuum, the pump must be left running
for about an hour with the gas ballast valve open.
This will eliminate any humidity from the oil.
,
WARNING!
The pump is designed for operation with neutral or
non-corrosive fluids. It is absolutely forbidden to
use potentially explosive or flammable substances.
NOTE
If the pump is started with cold oil, initially more
than normal noise will be heard; this will last for a
few minutes only until the oil reaches its working
temperature.
There are no special instructions for normal opera-
tion of the pump, which is delivered to you after
completion of a running-in cycle in the factory.
If the pump is sucking in environments with liquids
or vapors, it is important to leave it to run with the
gas ballast open so as to avoid condensation of
the vapors and contamination of the lubricating oil
as a result. When there is no danger of the oil be-
ing contaminated, the gas ballast valve should be
closed to reduce the pump’s power absorption.
The gas ballast valve will prove useful in the cold
season when, due to the lower room tempera-
tures, it takes longer for the pump to reach rated
temperature when switched on. Compression of
the air forced in by the gas ballast valve develops
heat, which in turn increases temperature of the oil
faster.
NOTE
If gases without vapors are sucked in, you are ad-
vised to open the gas ballast device from time to
time in order to eliminate the traces of humidity
they contain.
NOTE
For repetitive work cycles, with brief time intervals
in between, it is better not to stop the pump.
16 87-900-978-01(D)