YOKOGAWA UP750, User Manual

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<Toc> <4. Operations>
4-11
IM 05E01B02-41E 1st Edition : May 31,2000-00
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Controller Behavior and Control Output Manipulation when the Dead Band
is Positive
The following is an example when the DB parameter is set at 12.4%.
If you hold down the key with the heating-side output under manipulation (i.e., cooling-
side output C = 0.0%), the heating-side output (H =) decreases. Consequently, both the
heating-side and cooling-side outputs change to 0.0%. If you keep the
key held down
longer, you enter the state of manipulating the cooling-side output, and its value begins to
increase.
Inversely, if you hold down the key with the cooling-side output under manipulation
(i.e., heating-side output H = 0.0%), the cooling-side output (C =) decreases. Conse-
quently, both the heating-side and cooling-side outputs go to 0.0%. If you keep the
key
held down longer, you enter the state of manipulating the heating-side output, and its value
begins to increase.
Cooling-side
manipulated output
Heating-side
manipulated output
Output (%)
DB=12.4
Dead band:
Operating parameter DB
12.4 0 -12.4
Change in manipulated output when the dead band is positive
●
Controller Behavior and Control Output Manipulation when the Dead Band
is Negative
The following is an example when the DB parameter is set at -12.4%.
If you hold down the key with the heating-side output under manipulation (i.e., cooling-
side output C = 0.0%), the heating-side output (H =) decreases. If the output H falls below
24.8%, the cooling-side output C begins to increase from 0.0%. If you keep the
key
held down longer and the output C rises above 24.8%, the output H goes to 0.0% and you
enter the state of manipulating the cooling-side output.
Cooling-side
manipulated output
Heating-side
manipulated output
Output (%)
24.8
DB=-12.4
12.4 0 -12.4
Change in manipulated output when the dead band is negative