18
When the unit is switched on for the first time
or after a lubricant change the contact to the
lubricating pump can open as a result of the
degassification of the lubricant. In such cases,
as for other malfunctions, the electronic drive
unit shuts down the turbopump.
➡
The turbopump must be re-started with switch S1 on the
power supply.
☞
PLEASE NOTE
4.4. Gas Type Dependent Operations
Where high level gas loads and rotation speeds are involved,
the resulting friction subjects the rotor to the effect of great
heat. To avoid over-heating, a power rotation speed
characteristic line is implemented in the TC 750; this ensures
that where maximum gas loads are involved, the pump will
operate at any rotation speed without the danger of damage
arising. This power rotation speed characteristic line applies
only to operations with a cooling water temperature of 25 °C
and a cooling water flow rate of 100 l/h.
The maximum power is dependent on the type of gas. Two
characteristic lines are available for any type of gas in order
to fully exploit the power potential of the pump:
– Gas mode “0" for gases with molecular mass
≥
40 as, for
example, Argon;
– Gas mode “1" for all lighter gases.
Works setting: Gas mode “0”
➡
Set the applicable gas mode on the TC 750 via the DCU or
HPU (please refer to the respective operating
Instructions).
Pumping gases with molecular mass
≥
40 with
the incorrect gas mode can cause damage to
the pump. When pumping noble gases heavier
then Argon ist can come to the destruction of
the pump. Please contact the manufacturer
before using such gases.
For the vertex of the power characteristic line please refer to
Section 9. Technical Data.
Maximum power is applied when the pump starts in order to
limit the time required. Once the set rotation speed is
attained, switching to the selected power characteristic line
is automatic.
If the gas dependent maximum power is exceeded, the
rotation speed is reduced until equilibrium between the
permissible power and gas friction is attained. The power
limitation serves to protect the pump against thermal over-
loading. In order to avoid rotation speed fluctuations it is
recommended to set, in rotation speed setting mode, the
equilibrium frequency or a somewhat lower frequency.
WARNING
Power
Frequency
D
B
C
A
D-C = Gas mode «0»
B-A = Gas mode «1»
Run up
fnom
Gas type characteristic line
4.3. Switching ON
➡
Switch on the turbopump with switch S1 on the power
supply.
– Once the self test has been successfully completed on the
TC 750 (duration approximately 30 seconds), both the
turbopump and the backing pump (if connected) begin
operating.
F1
Rear panel, TPS 600
S1 ON/OFF switch
X1 Mains connection
X2 Connection TC 750
F1 Fuse
F2 Fuse
S1
F2
X1
X2
