RDZ UMHPI, User Manual

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UMHPI
Industrial inverter air/water heat pumps with axial fans
16
7.5.3 FAN SPEED CONTROL IN HEATING MODE
The fan speed control in heating mode follows the diagram shown below, where:
F10 = Delta cut-off of the fan in cooling/heating mode
F11 = Cut-off hysteresis in cooling/heating mode
F15 = Minimum fan speed in heating mode
F16 = Maximum silent fan speed in heating mode
F17 = Set pressure for the 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 11.5 for changing the parameters.
7.6 MODULATION FOR OIL RETURN
If this function is enabled in the factory, the return oil cycle will be performed during the compressor startup at the frequency C3
for the period of time C51-C11 .
7.7 DEFROSTING CYCLE
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). Please see paragraph 11.7 for changing the parameters.
7.7.1 DEFROST OPERATION SIGNALIZATION
You can configure a digital output for the defrosting process function notification.
In order to enable such function, you should enter into the parameters as following: press PRG

PSS

PRG

(then insert the
service password)

PRG

PAr

PRG

CnF
See paragraph 11.2.
Parameter Unit Value Description Terminals Notes
*H61 num 21
Undervoltage output for notification
of the defrost process NO1(Phase)
N1(Neutral)
Undervoltage output 230V ac, 50Hz, 5A resistive, 1A inductive.
Connect this output to the relay coil in order to get a free
contact.
(*) Alternatively, it is possible to use another output DO or OC , see paragraph 6.5.