Mechanical Connections; Operation; Cleaning The Pump; Startup Procedure - Agilent Technologies SH-112 Bedienungshandbuch

Mechanical Connections

Isolation Valve
The SH-112 has an integral automatic isolation valve. An
internal timer opens the valve 10 seconds after the pump
is switched ON. If power is lost or the pump is switched
OFF, the isolation valve will immediately close.
Pump Inlet
Use NW25, or larger, clean vacuum hardware with as
short a length as practical between the pump and vacuum
chamber.
Insert a bellows between the pump and vacuum chamber
to provide both vibration isolation and strain relief.
Pump Exhaust
A female 1/4" National Pipe Thread exhaust fitting is
located radially near the front of the pump. 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 tub-
ing. Use as short as practical lengths of NW16, or larger,
diameter hardware.
Gas Ballast
The pump incorporates an automatic gas ballast to pre-
vent water and other condensates from accumulating
within the pump. The standard configuration has a solid
plug installed in the 1/8" National Pipe Thread gas ballast
port (item 6 on Figure 3 on page 17). This configuration
can be used for relatively dry applications. A sintered fil-
ter plug is also supplied with the pump. The filter plug
can be installed in the gas ballast port and will allow
enough atmospheric air to enter the pump to purge con-
densates while not affecting pump ultimate pressure or
pumping speed.
For applications where the ingress of atmospheric air is
undesirable, dry nitrogen at a flow rate of approximately
2 L/m can be bled into the gas ballast port.
The gas ballast must be sealed when-
WARNING
ever pumping any gas not intended to
be vented to atmosphere.
SH-112 Dry Scroll Vacuum Pump

Operation

Cleaning the Pump

Unlike conventional oil-sealed pumps, Agilent dry scroll
pumps do not contain fluid for the cleansing of accumu-
lated dust and debris. Run the pump periodically at atmo-
sphere for a minute or two to flush it out. Until
experience is gained on your specific process, flush the
pump regularly and adjust this schedule according to
your specific conditions.

Startup Procedure

1. Make sure that the pump is configured for the mains
voltage to which the pump is connected.
The pump ON/OFF switch is a rocker
NOTE
type switch that has symbols in accor-
dance with IEC Publication 417 to
represent the ON and OFF positions.
Figure 5 shows a switch in the ON
position.
ON
Figure 5 ON/OFF Power Switch
2. Switch the pump ON.
3. The isolation valve will open automatically
10 seconds after starting the pump.

Shutdown Procedure

To shutdown the pump:
1. Switch the pump OFF.
The isolation valve will close very quickly to isolate
the vacuum chamber from the pump.
OFF
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