TECHNICAL INFORMATION
67
87-900-854-01 (C)
Operating the Pump
After the starting period, if the system has a vacuum
leak or the pressure in the pump/chamber is high (from
1 mbar to atmosphere), the pump continues to operate
indefinitely.
If the gas load at the turbopump inlet flange continues
to stay high, the power drawn by the turbopump
increases up to the maximum value. Than the Turbo-V
pump is slowed down in proportion to the gas load at
least until it reaches 3 KRPM.
Even if any previous display selection was made.
This will occur either in NORMAL operation or with the
LOW SPEED selected.
As soon as the gas load decreases, the pump will
automatically accelerate to reach normal operation.
The pump can be stopped at any rotational speed and
can be restarted at any rotational speed from either the
front panel buttons or the remote connections.
The controller automatically synchronizes the output to
the rotational speed of the pump and then accelerates
linearly up to the nominal speed or within steps if the
Soft Start has been selected.
Low Speed Operation
NOTE
With the FRONT panel operation selected, the remote
and RS 232 operations are inoperative; conversely, the
CYCLE NUMBER and PUMP CURRENT pushbuttons
are always active, even when the operating mode
selected is REMOTE or RS 232.
This feature is provided for operating the pump at
moderate high pressure with high gas throughput. To
operate in this low speed mode, engage the LOW
SPEED pushbutton once if the display shows
R E A D Y
F O R
L O C A L
S O F T
S T A R T
or:
P U M P
R E A D Y :
P U S H
S T A R T
B U T T O N
or:
N O R M A L
O P E R A T I O N
X X
K R P M
or twice if the display shows other parameters, either
before starting the pump or after it is operating.
If LOW SPEED is selected before starting the pump,
the display shows:
R E A D Y
F O R
L O C A L
S O F T
S T A R T
L S
The pump reaches the Normal high speed, then
decrease the speed to the low speed value and the
display shows:
A P P R O A C H I N G
L S
X X
K R P M
L S
If the Soft Start has been deselected the display shows:
P U M P
R E A D Y :
P U S H
S T A R T
B U T T O N
L S
where:
LS
= means low speed mode is selected.
After starting, a
LS
appears on the right bottom corner
of the following displays:
S O F T
S T A R T
O N
[
-
-
-
-
-
-
-
-
-
-
] L S
P U M P
I S
S T A R T I N G
1 2
X X
K R P M
L S
N O R M A L
O P E R A T I O N
X X
K R P M
L S
