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USER MANUAL – Release 1.2 of 01/01/2010
Page 144 of 191
Version: 02/03/2010
53.6.3 DEFROST OF THE AIR-WATER UNITS (ONLY WITH CF02=2 O CF02=3)
Defrost has priority over the production of domestic hot water.
If the controller determines the necessity to perform a defrost cycle while the production of domestic hot
water is active, the following steps are taken:
•
Passage to the production of heating water by activating output 2 and, after the delay FS10, by
deactivating output 1 and all of the heaterss and compressors on for the production of domestic hot
water
•
Deactivation of the circulation pump for the domestic hot water with delay FS27 from the change
over of the outputs for domestic hot water
•
Execution of the defrost cycle following the normal procedure respecting the typical times of this
cycle.
On conclusion of the defrost cycle:
•
If the production of domestic hot water is requested, the following actions will be taken:
o
Switch-on of the compressors and any heaterss
o
After delay FS11 from the end of the dripping time activation of the circulation pump for the
domestic hot water
o
After the delay FS26, the output 1 is activated for the production of domestic hot water.
o
After the delay FS10, the output 2 is deactivated for the production of domestic hot water.
•
If the production of domestic hot water is not requested, the controller will perform normal temperature
control.
53.7
PRODUCTION OF DOMESTIC HOT WATER WITH AIR/WATER UNIT,
WATER/WATER IN HEATING AND DEDICATED RETURN MODE: CF01=1,2 - CF02=3 -
FS01=2
53.7.1 DOMESTIC HOT WATER DURING WORKING IN WINTER MODE
Whenever there is a domestic hot water request, first the circulation pump is activated for the domestic hot
water and then, with delay FS26, output 1 is activated for the production of domestic hot water. When the
delay time FS10 has passed, the output 2 is deactivated for the production of domestic hot water and
temperature control will be carried out according to the layout on the previous pages. This working mode is
kept until the FS03 set is reached.
Once the domestic hot water set has been reached, output 2 is activated for the production of domestic hot
water and, after the delay FS10 output 1 is deactivated for the production of domestic hot water. When the
delay time FS27 has passed, the circulation pump for domestic hot water is deactivated
and classic
temperature control takes place on the water of the utilities circuit.
In the case of air-water unit, ventilation is managed normally depending on the evaporation pressure.
53.7.2 DEFROST OF THE AIR-WATER UNITS (ONLY WITH CF02=2 O CF02=3)
Defrost has priority over the production of domestic hot water.
If the controller determines the necessity to perform a defrost cycle while the production of domestic hot
water is active, the following steps are taken:
•
Passage to the production of heating water by activating output 2 and, after the delay FS10, by
deactivating output 1 and all of the heaterss and compressors on for the production of domestic hot
water
•
Deactivation of the circulation pump for the domestic hot water with delay FS27 from the change
over of the outputs for domestic hot water
•
Execution of the defrost cycle following the normal procedure respecting the typical times of this
cycle.
In the case of a single circuit unit if, during the production of DHW; the temperature of the water to the
utilities drops below the threshold defined in parameter FS45 and simultaneously the external temperature is
lower than the threshold defined in parameter FS47, the production of DHW is suspended and the
production of water for the utilities is started again until the temperature of the water goes back above the
threshold FS45 plus the offset FS46. This is to prevent any defrost from making the temperature of the water
to the utilities drop below the anti-freeze limit, thus blocking the unit.
