HWA1-A
Air/water chillers with axial fans
14
F11
= Cut-off hysteresis and silent/maximum fan speed
F13
= Maximum fan speed in cooling mode
F14
= Set temperature/pressure to the maximum fan speed in cooling mode
F6
-
F10
= Set forced fan stop for low condensing pressure
The fan operation control in heat pump mode occurs following the diagram shown below, where:
F10
=
F10
= Delta cut-off of the fan motor in cooling/heating
F11
= Cut-off hysteresis in cooling/heating
F15
= Minimum fen speed in heating mode
F16
= Maximum silent fan speed in heating
F17
= Set pressure for minimum fan speed in heating mode
F18
= Fan speed linear band in heating mode
F19
= Maximum fan speed in heating mode
F20
= Set pressure for the maximum fan speed in heating mode
F17+F10
= Set forced fan stop for high evaporating pressure
The fan speed can be controlled via analog/digital outputs or, alternatively, via serial on the same serial of the modulating
compressor. Please see paragraph 17.5 for changing the parameters.
10
Defrosting cycle management
The defrost cycle function is available only in heat pump mode and is used to prevent the frost formation on the surface of the
air/air coil. The frost formation on the evaporator, which occurs more frequently at very low ambient temperatures, in addition to
greatly decreasing the thermal efficiency of the unit, it can lead to the risk of damaging the unit itself. The adjustable parameter
d01
enables the defrost operation (=1 enabled defrosting).
10.1
Forced manual defrost
If the appliance is ON and in heating mode, you can force manually the defrosting mode by pressing the UP, DOWN, and ENTER
buttons for 3 seconds.
The same thing can be done via serial, sending the modbus 200 register value '-1'. This writing will not change the state of the
appliance, but only leads to forced manual defrost.
11
ANTIFREEZE PROTECTION ELECTRIC HEATERS (IF THE KA ACCESSORY IS PRESENT)
The antifreeze electric heaters (installed on the outer surfaces of the evaporator plates) and the heating cable placed on the
basement of the appliance turns on when the outdoor air temperature decreases below 3°C and the unit goes in defrosting
operation (or if
r19
=0 even if the unit is not in defrosting cycle, or in stand-by mode). The previous heaters will be stop operation if
the outdoor temperature exceeds 5°C or the last defrosting is terminated after more than r19 minutes (default 10 minutes) (with
r19
≠0).
Summary of Contents for HWA1-A 0140
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