Viessmann VITODENS 200 - Cascade Combo

41
Cascade combo
Although the lowest Outside Temperature Climazone temperature setting is -4ºF / -20ºC, the Cascade Control
can accommodate lower outside temperatures. The graph below illustrates how a slope can be programmed for
a design temperature of -40ºF / -40ºC at 158ºF / 70ºC boiler supply temperature.
The Outside Temperature Climazone Point has been programmed for 14ºF / -10ºC and the Flow Temperature
Climazone Point for 113ºF / 45ºC. Even though the control is set to 14ºF / -10ºC, the control continues to
calculate a supply temperature as the outdoor temperature drops. It will continue to do so until the maximum
supply temperature of 165ºF / 74ºC has been reached. With respect to the curve below, this maximum
temperature will not be reached until the outside temperature drops below -40ºF / -40ºC.
Starting point for both sloped lines: Outside Temperature Fixed Point and Flow Temperature Fixed Point
and Normal Room Temperature.
End point for curvature. Calculated supply temperature continues based on outdoor temperature shown by
dotted line. It is only limited by maximum boiler water temperature.
Dotted line shows sloped line with no curvature setting. Maximum temperature limited by Vitodens 200
boiler.
Curvature setting only affects section of slope between points and . Once the curve gets past point
, the line continues to maximum supply temperature setting.
Gradual increase of supply temperature. Line flattens out after point . Notice change in slope until
maximum temperature reached. The portion of this line affected by heat curvature setting. The lower the
curvature setting the greater the slope after point
and vice versa.
5285 565 v1.35285 565 v1.3
20
68
15
59
10
50
25
77
30
86
35
95
40
104
5
41
0
32
-5
23
-10
14
-15
5
-20
-4
-25
-13
-30
-22
-35
-31
-40
-40
176 80
158 70
140 60
122 50
104 40
86 30
68 20
50 10
Outdoor Temperature
°C
°F
°C°F
Supply Temperature