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Heating PID
180
Temperature setpoint 1 in heating mode
181
Temperature setpoint 2 in heating mode
182
Temperature control PID proportional band (P) in heating mode
183
Temperature control PID integral time (I) in heating mode
184
Temperature control PID derivative time (D) in heating mode
Supply air limitation
When control is being applied to the return air or room air, the supply air temperature can be limited. This limitation is used to avoid
blowing air at too high a temperature in heating mode or too cold a temperature in cooling mode. This limitation is activated by parameter
P156. A PI controller (proportional-integral) limits the heating or cooling requirement. If integral control is deactivated (P233=0), the
proportional band (P232) must be approximately 5°C, so as to prevent too high or too low a supply air temperature.
Cooling request
limitation
Proportional band P232
Integral time P233
Supply air
lower limit setpoint:
P230
Supply air
temperature
Low
threshold
fault P240
100%
0%
Supply air
temperature
Supply air
upper limit setpoint:
P231
Proportional band P232
Integral time P233
High
threshold
fault P241
100%
0%
Heating request
limitation
156
Supply air limitation = With or Without
230
Supply air temperature low limit setpoint
231
Supply air temperature upper limit setpoint
232
Supply air temperature limit proportional band
233
Supply air temperature limit integral time
When the cooling requirement is minimised, cooling compensation is used to start up the heat recovery unit or close the bypass if the
supply air temperature is less than P230-2°C (if P230>0) or P230-P232 (if P230=0). This function prevents excessively cold supply
air (outside air) if there is a cooling requirement and the outside air is cold (excluding night cooling). This compensation is proportional
control of a 5°C proportional band.
There is hysteresis on the cooling requirement and supply air temperature, to prevent inadvertent starts/shutdowns.
Cooling compensation
Heat recovery unit demand
Proportional band
P232 if P230 = 0
2°C if P230 > 0
5°C
Supply air lower limit
setpoint: P230
Supply air
temperature
Low
threshold
fault P240
100%
0%
10%
3 - FEATURES
18
Summary of Contents for 39HXC
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