VACUUBRAND PC 3012 VARIO plastic housing - Manual (Page 57)

page 57 of 129
Pump down function
➨
Continuous pumping with pressure and time settings
• Operation on demand of a speed controlled NT VARIO / VARIO-B
pump
Preselections
+
Use the selection knob to select the parameters. All parameters can
be altered even while operation control is running.
+
Speed: Preselection of the motor speed for pump down. The selec-
tion ”HI” effects the maximum speed and best ultimate vacuum of the
pump (with automatic speed reduction at ultimate vacuum).
The ”Speed” is adjustable in a range of 1-100% and to ”HI”.
+
Minimum: The controller switches the pump off once the preset value
for ”Minimum” has been reached.
”Minimum” is adjustable in a range of 1-795 Torr (1-1060 mbar) or can
be set to ”Off”.
A preset ”Duration” (process time) has no effect if the process is
stopped due to a preset ”Minimum” before ”Duration” is reached.
+
Delay: ”Delay” determines the time the coolant valve remains open
after the process has been stopped.
The ”Delay” is adjustable in a range of 1-300 minutes or can be set to
”Off” (”Off” means that the coolant valve closes immediately when the
process stops.).
+
Duration: ”Duration” determines the total process time since control
start.
The process time is adjustable between 1-1440 minutes (24 h) or can
be set to ”Off”. ”Off” indicates that no endpoint for pump down is deter-
mined.
If a ”Duration” is preset, the controller switches off the pump when the
preset process time is reached, even if a preset ”Minimum” is still not
reached.