After START command, frequency output will be at the
maximum level, then the frequency will decrease to a
value proportional to the pump rotational speed (about
12 Hz if the pump is completely stopped).
The pump will accelerate to its normal rotational speed.
•
During acceleration of the pump or during any
operating condition, it is always possible to select
the other parameters to be displayed pressing the
PUMP
CURRENT
pushbuttons.
•
After the runup time or when the normal rotational
speed is reached, the display will be as follows,
even if any previous display selection was made,
and the normal condition has been reached.
N O R M A L
X X . X
K R P M
where:
XX.X
=
indicates
(14.0 KRPM for high speed, or 9 KRPM for low speed)
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 (1200
W).
Than the Turbo-V pump is slowed down in pro- portion
to the gas load at least until it reaches about 0.7
KRPM.
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
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 push-button once if the display shows:
or
the
CYCLE
NUMBER
O P E R A T I O N
the
rotational
speed
R E A D Y
S O F T
or:
P U M P
R E A D Y :
P U S H
S T A R T
or:
N O R M A L
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
S O F T
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 C H I N G
X X . X
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
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
[ - - - - - - - - - - ]
P U M P
1 2
X X
N O R M A L
X X
and when the pump reaches the low speed value,
display reverts to:
71
TECHNICAL INFORMATION
F O R
L O C A L
S T A R T
B U T T O N
O P E R A T I O N
X X
K R P M
F O R
L O C A L
S T A R T
L O W
S P E E D
K R P M
B U T T O N
S T A R T
O N
I S
S T A R T I N G
K R P M
O P E R A T I O N
K R P M
87-900-855-01 (B)
L S
L S
L S
L S
L S
L S