
Must be allowed to define the Outdoor air temperature below which the water will be heated with Heat pump unit +
EHS.
Set the parameters for Par4701=0 (always enabled), or Par4701=1 (depends on Outdoor air temperature).
If Par4701=0, EHS is ON based on Par4707 (Integration time for starting EHS) is enable regardless to the Outdoor
air temperature.
If Par4701=1, EHS can be turned ON only if the both of the following conditions are met
Par4704 (Outdoor air temperature to enable Backup heater)
Par4707 (Integration time for starting heaters)
(-5.0°C)
hysteresis
Outdoor air
temperature
Compressor ON
OFF
EHS ON
OFF
EHS + Heat pump
Heat pump
EHS
EHS + Heat pump
Heat pump
EHS
hysteresis
Par4073
Par4072
Par4074
Par4075
(0.0°C)
(5.0°C)
(10.0°C)
Note1: The calculation of the Integration time only begins after the time set for Par4706 (EHS activation delay) has
elapsed. The function is designed to prevent the EHS from starting in Supplementary mode, to allow the HP
unit time to reach steady operation.
Note2: If the Integration time for starting the EHS is 0, control will be in stages, based on the control set point and
the value set for the hysteresis.
Note3: If the HP unit shuts down due to the Outdoor air temperature being below its operating limit and due to the
Max. water temperature produced based on the Outdoor air temperature, the heater will operate in
Replacement mode.
Note4: If Terminal46 (Electric heater) will be enabled as Backup heater, the “EHS for space heating” will be not
allowed. To guarantee correct operation, the two functions cannot be activated at the same time.
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8. Domestic Hot Water Production
Summary of Contents for AEYC-0639U-CH
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