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10 Digital Communication Interface
Cooling Control
10.4
Cooling Control
The 7340 bath has a fully automated refrigeration control system when the
cooling power switch on the front panel is activated. Under normal conditions,
the refrigeration is on at any temperature below approximately 60°C (see Section 8.6, Refrigeration). When the bath is controlling at temperatures between
0°C and 60°C, the refrigeration is in the hot gas bypass or reduced cooling
mode. Below 0°C the refrigeration is in the high cooling mode, the hot gas bypass is turned off automatically. When the bath is cooling from one temperature
to another below 60°C, cooling is at maximum until the bath is within 1 degree
C of the set-point. These conditions are the default conditions but may be altered in the following ways.
• The cooling (refrigeration) may be set to operate in the auto, on, or off
modes. See Section 9.13.2, Cooling Mode.
• The hot gas bypass or reduced cooling mode may also be set to on, off, or
auto.
The “auto” modes allow the bath to operate automatically in the manner described above. The cooling “on” function eliminates this auto feature and the
refrigeration is on at all times unless the front panel switch is turned off or until
some other menu selection is made. The hot gas bypass mode selection works
the same way. The “auto” function is the default and active until off or on is selected. “On” means it is always on with no automatic selection and “off” is always off (or cooling always on maximum). It may desirable for different
reasons to eliminate the automatic functioning; therefore, these selections are
made available either through the front panel or through the digital communications interface.
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