Carel k.Air, Руководство пользователя, Страница: 56 / 192

56
Functions
k.air +030220981 rel. 1.2 - 01.12.2020
30220980_188_R01
SEQUENCE PID
REGULATION
Request 1 (%)
Request 2 (%)
...
Request n (%)
Device 1 limits
Device 2 limits
Device n limits
Activation 1
Activation 2
Activation n
Fig. 9.g
Two control functions use sequential PID:
1. Single point control temperature control (supply, return, room) or when subordinated to cascade control (room + supply, return
+ supply)
2. Air quality control
Temperature control in cooling mode
30220980_190_R01
Regulation
probe (°C/°F)
%
set
Freecooling Recovery IEC Main coil Fan speed
Fig. 9.h
Temperature control in heating mode
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Regulation
probe (°C/°F)
%
set
Freecooling Recovery IEC Main coil Fan speed
Fig. 9.i
Note:
freecooling/freeheating and heat recovery are considered alternatives, as during freecooling/freeheating the bypass
damper is open and heat recovery is disabled.
Air quality control
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CO2 (ppm)
%
set
Fresh air Fan speed
Fig. 9.j
Calculation of the request for each device
The fi rst request is calculated as shown in Fig. D1, where only the proportional part is shown. If there are two devices, the set
point is the same and the second request starts when the fi rst has reached 100%. The request sent to the second device is equal
to A, but according to the incremental PID algorithm, the second request also starts from zero, as if the curve for the second
device were shifted to the right by the value of Diff _1.