Operation
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6
Operation
6.1
LVS without vacuum controller
Switch the device (LVS 600 T, LVS 601 T, LVS 602 T) on using the main switch. Vacuum is
generated immediately and without regulation. Over the regulating valves on the LVS 602 T
it is possible two customers concomitant to connect.
6.2
LVS with vacuum controller
The LVS is switched on by the rocker switch
POWER
located on the device.
The device is ready for operation after a short initializing routine, during which a signal tone
sounds and all light elements light up briefly.
In the version
LVS with external controller
(Order no. 115254-04)
is the on / off power
switch on the controller.
6.3
Operating modes of the Controller
The following modes are available:
0 -
STOP
Controller is inactive and can be configured
1 -
Manual operation
With specification of the setpoint and, if required, lowering
2 -
Automatic operation The setpoint is detected automatically from the pressure development
3 -
Ultimate pressure
Pumping out at maximum motor output
4 -
Self cleaning
Motor runs for 2 minutes at open ventilation valve
6.3.1
Mode 1, Manual operation
The vacuum valve is closed when the pressure reaches the setpoint. Closed-loop control be-
tween the set hysteresis and the setpoint has been started.
For
operation with a frequency converter
, an analog voltage is output, which controls the
speed according to the standard tolerance. If the set pressure is not reached, the speed is
automatically adjusted to the pressure loss.
If the pressure is actively lowered, after the setpoint has been reached for the first time, it is
lowered still further within a settable timeframe. The number of ramps can be set up to a
maximum of 3. Each ramp starts with a holding time. The setpoint then falls in one step to
the defined starting pressure. The setpoint then falls to the final value over the set time.
After the last ramp, there is a waiting time until the automatic
STOP
(0 – the last set pressure is held indefinitely until
STOP
is pressed manually).
CAUTION !
When setting the ramps make sure that the set value is greater than or equal to the
starting value of the first ramp.
The closed-loop control and hysteresis are always related to the current (reduced) setpoint.
The changed setpoint always applies until the
STOP
button is pressed, then the configura-
tion value applies once more. When the pressure reduction has finished, the control is
stopped, and the system waits until the
STOP
button is pressed.
6.3.2
Mode 2, Automatic operation
After selection of the operating mode, the controller starts the evacuation. The pressure drop
per minute is determined during this process. If increases during distillation by incipient boil-
ing of the pressure, then this pressure value is taken as the setpoint and proceeds in the
normal control operation.
