Refer to Figure: Front panel controls. To enable the Green mode/standby mode when
the pump is running and warmed up, press and hold the start buon (item 3) for 5
seconds. The pump green mode LED (item 10) will illuminate connuously. The pump
running LED (item 2) will ash.
To disable Green mode/standby mode, and therefore to enable the on‑process mode,
press and hold the start buon (item 3) for 5 seconds. If the pump has warmed up, the
pump green mode LED (item 10) will go out and the pump running LED (item 2) will
illuminate connuously. If the pump has not warmed up, both the Green mode LED and
the pump running LED will ash unl the pump is fully warm. The Green mode LED will
then go out and the running LED will illuminate connuously to indicate that the pump is
now on‑process.
Table 21
Green mode/standby sequence
Sequence Descripon
Green mode/Standby Inlet isolaon valve is closed (if ed).
Pump runs at standby (Green mode) speed.
Gas ballast valve is closed (medium‑duty pumps only).
If the pump temperature drops below working temperature
then it will start to warm up again.
Pump ready line will be o if pump is not warmed up.
The dry pumping system can also be set into Green mode/standby mode using the
following methods:
▪ PDT, by the commands menu. Refer to Commands menu on page 124.
▪ MCM MicroTIM. Refer to the MicroTIM manual D37360880.
▪
By commands sent over the serial interface using the SIM protocol. Refer to the
SIM Manual P41100200, or using the E54 protocol.
4.4 Pumping Argon
Due to its inert nature, Argon is commonly used in the heat treatment and other
metallurgical applicaons, especially at high temperatures. The thermodynamic
properes of Argon can give challenges and dicules when it comes to the vacuum
pumping systems. The inherent thermal properes of Argon including its ineciency to
transfer heat away to the cooling system which, if not controlled, can cause the
problems for dry vacuum pumps. If heat is not successfully removed from the rotors, a
dierenal thermal expansion can cause seizures.
The GXS160, GXS250 and GXS450 (with or without booster) can pump Argon with no
restricons.
The GXS750, GXS750/2600 or GXS750/4200 is capable of pumping Argon but not
connuously at all pressures. At 110 Hz, the connuous operang range is restricted to
less than 20 mbar at the inlet to screw pump (this is equivalent to 10 mbar at the inlet to
booster). To extend the connuous operang range up to 500 mbar and to enable the
pump down of the large chambers, the operang speed of the pump must be reduced to
80 Hz. This is valid with Argon at ambient temperature.
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M58800880_H - Operaon