Service
-
131
-
'10 • HM-T-149
Supply water temperature control in coonling
Principle such as cooling curve, cooling curve offset and upper/lower limit is the same as heating operation.
Target supply water temperaure can be checked inMenu 2.0.
Cooling curve can be chosen in Menu 2.2.2
Cooling curve
Cooling curve is the basic principle to decide the target supply water temperature for cooling.
The higher the outdoor air temperature (BT1) becomes, the lower the target supply water temperture becomes, and the characteristics
can be adjusted in Menu 2.2.2.
The gure below shows the characteristics of cooling curve. When cooling curve 1 is chosen, target supply water temperature is
around 16°C at 35°C outdoor air temperature condition.
Upper/Lower limit of the supply water temperature
Regardless of the cooling curve setting and the outdoor air temperature, target supply water temperature can not exceed the min/max
supply water temperature set in Menu 2.2.4 and 2.3.
Upper and lower limit is set after various offset correction.
Water temperature control when deviated from the target
When the DM value is signif icantly big, supply water temperature must be controlled lower than target temperature to reduce the
surplus of DM value. However, too big overshoot of the supply temperature will affect comfort.
In order to control the supply water temperature to avoid f luctuation of room temperatre, overshoot limit is set in Menu 9.6.7 (Max
diff f low-cFlow). Once the supply water temperature reaches the threshold of Menu 9.6.7, thereafter the compressor speed is
controlled so that the supply water temperature is kept above the overshoot limit.
Operation control function by the indoor unit controller