Temperature Range Control Functions - Fluke 7012 User Manual

beled "HIGH" controls the cooling temperature when the expansion valve is
open or on. This should be adjusted for approximately 45–50 psi. These values
are typical but may be adjusted as required for specific applications. The low
range must be set to a lower pressure (temperature) than the high range valve.
The "F4" command controls the back pressure valve. When the valve is open
the cooling capacity is significantly reduced. This valve should normally be left
off/closed throughout the operating range of the bath. Table 5 summarizes the
control functions for heating and cooling. Table 6 shows the recommended
control settings for each operating temperature range. The ranges may need to
be adjusted depending on the bath application.
Table 5 Serial Power Control Functions
Function Command
Heater F1
Refrigeration F2
Expansion valve F3
Back pressure F4
Table 6 Temperature Range Control Functions
Range
–10 to 15°C
15 to 40°C
40 to 110°C
10 Digital Communication Interface
0
low
off
open
open
Heater Refr.
low on
low on
low/high off
Power Control Functions
1
high
on
closed
closed
Exp.
open
closed
open
57