The parameter menu Par
(Version number, program number, min, max, diff, auto/manual mode)
Once the parameter menu has been opened (using the code 32), the following tips and
setting options appear depending on the program selected:
VR 7.6
Software version of the device (VR = version with relay output, VD = speed ver-
sion). It cannot be changed as it indicates the intelligence of the device and must
be provided if there are any queries.
PR
Selection of the appropriate program according to the selected diagram. For a
solar thermal system, that would be the number 0.
The device does not have any switching differentials (difference between temperatures to
switch on or off); rather, all of the threshold values are divided into switch-on and switch-off
values. In addition, some programs have several similar thresholds such as max1, max2. To
make a distinction, the index for max is also displayed in the same line.
CAUTION: When setting the parameter, the computer always limits the threshold value (such
as max1 on) when it approaches a certain temperature of the second threshold (such as
max1 off) to prevent negative hysteresis. If a threshold cannot be changed any longer, the
second threshold has to be changed first.
max When this temperature has been reached, the output is blocked. (ex works=75°C)
max The output blocked at max is released again when this temperature has been
reached. max generally serves to limit storage. Recommendation: The switch-off
point should be some 3-5K higher than the switch-on point in the storage area and
some 1-2K higher than in the pool area. The software does not allow for differences
less than 1K. (ex works = 70°C)
min When this temperature has been reached at the sensor, the output is released
(display only with the corresponding program diagram).(ex works = 5°C)
min The output previously released via min is blocked again when this temperature
has been reached. min generally protects the boilers from soot. Recommendation:
The switch-on point should be some 3-5K higher than the switch-off point. The
software does not allow for differences less than 1K. (ex works = 0°C)
diff If the temperature difference between the two set sensors surpasses this value, the
output is released. For most programs, diff is the basic function (differential control-
ler) of the system. Recommendation: For solar applications, diff should be set
to around 7-10K (ex works = 8K). Slightly lower values suffice for the loading pump
program.
diff The output previously released when diff was reached is blocked again when
this temperature difference is reached. Recommendation: diff should be set to
around 3-5K (ex works = 4K). Although the software allows for a minimum differ-
ence of 0.1K between the switch-on and switch-off points, no value less than 2K
can be entered for sensor and measurement tolerance.
O AUTO The output is set to automatic mode and can be switched for test purposes to man-
ual mode (O ON, O OFF). When the manual mode has been selected, an icon ap-
pears under the text line. An active output (pump running) is displayed next to the
arrow icon ➢ below the text line. If this icon is not displayed, the output is blocked.
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