GA 12.137/2.02 - 05/2002
25
Operation
Key to Fig. 16
1
Display
2
Buttons
3
Main switch
4
Pressure gauge
Fig. 16 Control elements
RS 232/485
REMOTE
OFF
ON
COLD
HEAD
FUSES COLD HEAD
F1
F2
F3
MAIN SWITCH
OFF/ON
HELIUM
FILLING
HELIUM
LOW
PRESSURE
HELIUM
HIGH
PRESSURE
SELECT
3
4
1
2
Warning
Detaching the flexlines with the cold head at
low temperature can, when they heat up,
result in a rise in pressure beyond the per-
missible 28 bar (406 psig; 2.8 MPa) opera-
ting pressure. All the self-sealing couplings
which are not in use shall be provided with
protective caps.
Unscrew the flexlines in a sequence reverse to that
described in Section 2.6. Screw protective caps on to
the self-sealing couplings. Never ship compressor units,
flexlines, cold heads or adsorbers without the appropria-
te protective caps.
Vent the helium when the compressor unit is to be taken
out of service permanently.
3.4.1 Transport and storage
Store the compressor unit in a dry place. The maximum
relaive air humidity is 95%, non-condensing.
The permissible ambient temperature when transporting
and storing the unit is – 20
°
C to + 40
°
C (– 4
°
F to
+ 104
°
F). Temperatures above 40
°
C (104
°
F) may lead
to gas evolution from the adsorber and thus may conta-
minate the flexlines and the cold head.
The ambient atmospheric pressure must be 700 mbar or
above.
Warning
Even after the unit is switched off, the com-
pressor unit, the cold head and the flexlines
will be under pressure of up to 16 bar (232
psig; 1.6 MPa).
Observe the appropriate safety regulations.
If there is danger of freezing temperatures, drain the
coolant prior to storing or shipping the compressor unit.
The compressor unit may be tilted by a maximum of 45
°
during shipment and storage.
