VACUUBRAND PC 620 NT plastic housing - Manual (Page 56)

page 56 of 113
Vac Control function
➨
Vacuum control to a preset vacuum value
• Operation of a vacuum pump via in-line valve
• Operation of a vacuum pump without in-line valve via VMS (Vac-
uum Management System), see “Accessories”, pg. 86.
Preselections
+
Use the selection knob to select the parameters. All parameters can
be altered even while operation control is running.
+
Set vacuum: The ”Set vacuum” is the lower set point for two-point
vacuum control.
The ”Set vacuum” is adjustable in a range of 0-795 Torr (0-1060 mbar).
+
Hysteresis: The ”Hysteresis” is the control bandwidth of the two-point
control. A too small hysteresis will lead to frequent switching of the
valve or the pump. A too large hysteresis will lead to imprecise control.
Suggested ”Hysteresis” values (see table) are stored in the controller
(setup ”Auto”) and are adapted automatically to the preset pressure.
The hysteresis can be adapted at any time.
The ”Hysteresis” is adjustable in a range of 1-225 Torr (1-300 mbar) or
can be set to ”Auto”..
+
Maximum: An upper pressure limit can be preselected. The pump
switches off if the pressure limit is exceeded, e.g., at the end of suc-
tions or filtrations. The pressure limit is only active once the pressure
has gone below ”Maximum”.
The ”Maximum” is adjustable in a range of 794-1Torr (1059 - 1 mbar)
(at the least 1 Torr (mbar) higher than the ”Set vacuum”) and to ”Off”.
”Off” means that no ”Maximum” value is preset.
Set vacuum in Torr 5 10 50 80 100 200 500 700
Hysteresis in Torr
(suggested values)
2 2 5 8 9 17 40 55