Operating Modes - MAXA LWF 13 Benutzer- Und Installationsanleitung

6. TEMPERATURE CONTROL FUNCTIONS

6.1 OPERATING MODES

According to the models and options available, DRA-L works in the following operating modes:
● COOLING (summer setting)
● HEATING (winter setting)
● AUTO (automatic selection of summer – winter setting)
Cooling: this is the "summer" operating mode; the unit is configured to generate cold air.
Heating: this is the "winter" operating mode; the unit is configured to generate hot air.
Auto: the unit is configured to switch automatically from cooling to heating and vice versa depending on the temperature values detected
by the air probe.
The summer/winter setting (Cooling/Heating) can be manually set locally.
The operating mode is automatically selected according to the temperature detected by the air temperature probe.
6.2 THERMOSTAT CONTROL ON VALVE
In this case, fans are managed according to the operating mode selected (Cooling or Heating) as follows:
A) In Cool mode the fans run at the speed set with the fan slider or specified by the Autofan controller, and can be disabled by the Too
Cool function only. The speed shall be equivalent to the one set with the Fan slider (managed in AUTO mode if this mode is selected)
B) In Heating mode the fan follows the valve status (observing the activation delay time) and behaves as follows:
1) fan ON 60 seconds after the valve open command (signalled by flashing of the red LED);
2) fan OFF when valve close command is given.
3) the HOT START, POST VENTILATION and PERIODICAL VENTILATION are also enabled.
6.4 THERMOSTAT CONTROL ON FAN
This type of temperature control only uses the fans, the valve is not used (the hot or cold water goes into the coil inside the Fan Coil), and
the temperature controller works by enabling or inhibiting fan consent (observing the Heat and Cool set points).
The fans are controlled in the same way as the valves using the same set points and the same hysteresis.
If the controller is ON (fans on), the speed will be:
● manually set by the user (Min – Med – Max speeds permitted)
● set by AUTO_FAN at automatic speed if the fan slider is positioned on Auto mode.
With thermostat control on fans the Periodic Ventilation, Hot Start and Too Cool functions are activated.
7. FUNCTIONS
7.1 AUTOMATIC CHANGE OVER
The Automatic Change-over function (AUTO-CHANGE OVER) automatically selects the Heating/Cooling mode according to the ambient
temperature and enables the controller to control machine operating independently.
(**)
● The Heat mode is selected if:
value read by the ambient probe (control or remote) < Heat set point for change-over (according to set point in Heating + 2°C (delta
changeover))
● The Cool mode is selected if:
value read by the ambient probe (control or remote) < Cool set point for change-over (according to set point in Heating + 2°C (delta
changeover))
As soon as the machine goes into Auto Change Over mode (at start-up or from another mode) ventilation is forced into medium speed
with duration set by the parameter (fan duration for change-over).
● during ventilation all resources (except for fans) stay OFF;
● the LEDs stay as they were for the previous state.
When ventilation is completed, the controller establishes which mode to go into according to **.
If the temperature value falls within the "dead zone", the controller will remain in the mode that it was in prior to the selected phase.
If the main temperature controller is satisfied for a minimum period equal to the change-over delay time Periodic ventilation is effected.
When the On period has terminated, the controller verifies the presence of change-over conditions.
If the ambient temperature falls within the dead zone (OFF area on graph) at Power-ON, the board goes into the condition prior to
Power-OFF (or if it was in Heat mode, it stays in this condition).
The fans behave in the same way as cases of manual Heat/Cool operating.
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