Bruker EPR 12T Cryogen Free, Руководство пользователя, Страница: 39 / 80

39 ZTKS0213 / Z31939 / Rev.: 01
Operation
5.5 Cooling Down
Precondition
• Magnet system is evacuated to a vacuum of better than 1 x 10
-4
mbar at room tem-
perature(see section "Evacuating the Cryostat" on page 28 ).
• Vacuum pump still running.
• Power supply operation Cernox mode.
• BCFC checked.
Procedure (Water cooled compressor unit F-50H)
• Make sure that the switches (1) and (2) are in default mode as indicated on the
yellow labels (see
Figure 5.12 ).
• Start the compressor F-50H using the switch "DRIVE" on the front panel of the
compressor (see
Figure 5.12 ).
• The rhythmic noise of the cold head will immediately start.
• The compressor status is displayed on the BCFC (see "Remote Compressor Status
Display" on page 33 ). The four indicators of the compressor (temperature okay, gas
pressure okay, input power, running) must be active (green).
• Use the "DISPLAY CERNOX" mode of the power supply to monitor the temperature
of the main coil. Cool down procedure from room temperature to base temperature
takes up to 96 h.
• When the system has reached base temperature close the vacuum valve and dis-
connect the pump (see section
"Rebuilding Vacuum" on page 31 ).
Procedure (Air cooled compressor unit CNA-61)
• Start the compressor CNA-61 using the "DRIVE SWITCH" on the front panel of the
compressor (see
Figure 5.13 ).
• The rhythmic noise of the cold head will immediately start.
Figure 5.12: Front panel of the compressor unit F–50H (water cooled)
1 COLD HEAD DRIVE (For Maintenance Only)
2 REMOTE DRIVE
3 DRIVE