Fan control - Basic Documentation - RDF600KN - RDF600KN/S - RDF600KN/VB

The fan operates in automatic mode or at the selected speed with manual mode.

• RDF600KN, RDF600KN/VB: Fan speed OFF: (P15 = 0, P60 = OFF)

• RDF301…: Fan speed 1 (P60 = 0)²⁾

1. P15 is not implemented into RDF600KN, RDF600KN/VB SW version < V1.8.

2. On RDF301 and RDF301.50, it is recommended that the fan is running in deadzone, i.e. P60=0, or using a return air- or external temperature sensor.

For this purpose, the fan command value needs to be enabled.

The fan speed and mode can be monitored via bus.

	w Room temperature setpoint
	Q Fan speed
	YH Control demand "Heating"
	YC Control demand "Cooling"
	XpH Proportional band "Heating"
	XpC Proportional band "Cooling"
	Xdz Dead zone

The diagram only shows the PI thermostat’s proportional part.

On applications with 2-position control:

1. The switching point for low fan speed (Q1) is synchronized to the heating / cooling output. Parameter "Switching point fan speed low" P57 is not relevant.

2. The maximum switching range of the fan (XpH_Fan / XpC_Fan) is defined by the switching differential (SDH/SDC) via a look-up table.

	T[°C] Room temperature
	w Room temperature setpoint
	Q Fan speed
	Y Control command "Valve"
	SDH Switching differential "Heating"
	SDC Switching differential "Cooling"
	Xdz Dead zone
	XpHFan Switching range for fan "Heating"
	XpCFan Switching range for fan "Cooling"

The thermostat can control a 1- or 3-speed fan (selected via control parameter P53). A 1-speed fan is connected to terminal Q1, a 3-speed fan to terminals Q1, Q2 and Q3.

In automatic mode, a dwelling time of 2 minutes (factory setting) is active. The fan maintains each speed for at least 2 minutes before it changes to the next speed. This minimum on-time can be adjusted from 1…6 minutes via parameter P59.

The periodic fan kick time can be selected individually for Comfort mode via parameter P60, and for Economy mode via parameter P61.

Fan kick value "OFF" means the fan does not run in the dead zone.

Via parameter P15 in "Service Level", the fan speed in the dead zone (in Comfort mode) can be set according to customer preference.

• Fan does not run in the dead zone (P15=0),

• Fan runs at low speed in Heating and Cooling mode (P15=1)

• Fan runs at low speed in Cooling mode only (P15=2).

The functions "Fan in dead zone" (P15) and "Fan kick" (P60) are combined as follows:

• P60 = 0 Fan runs continuously in the dead zone, P15 has no influence

• P60 = OFF Fan operation in dead zone according to P15.

When the fan starts from standstill, it starts at speed 3 for 1 second to ensure safe fan motor start by overcoming inertia and friction (selected via parameter P58).

When the electric heater is switched off, the fan overruns for 60 seconds (parameter P54) to avoid overtemperature of the electric heater or prevent the thermal cutout from responding.

In case of fan failure, the thermostat cannot protect the electric heater against overtemperature. For this reason, the electric heater must feature a separate safety device (thermal cutout).

The "Clean fan filter reminder" function counts the fan operating hours and displays message "FIL " to remind the user to clean the fan filter as soon as the threshold is reached. This does not impact the thermostat's operation, which continues to run normally. The function is set via parameter P62 (default = OFF (0)).

The "Clean filter reminder" is reset when the operating mode is manually set to Protection and back.

In Auto Timer mode , the default fan mode is automatic. The fan mode can be changed to Manual by pressing the FAN button. The fan returns to the automatic default mode after each switchover from Comfort to Economy mode, and vice versa.