Lennox LXTFF01M Installationsanleitung Seite 37

and not to the level, so it is always possible to change the on/off
status with the " " button (if enabled).
"Motor alarm" function
The input lights the " " icon on the display. When the alarm is
active, the electric heater output will be cut off.
"Electric heater alarm" function
When the alarm is activated " " + " " symbols fl ash on the display
and the electric heater output will be cut off.
The electric heater safety thermostat can be connected to this
input.
TEMPERATURE ACQUISITION
This controller acquires both the room temperature and the
delivery water temperature in the fan-coil exchanger with NTC type
sensors.
The room temperature is acquired and displayed with the above
mentioned resolution in the range -10°C .. +50°C.
The controller features an internal temperature sensor and also an
input for a remote sensor is also available.
The selection between internal or remore sensor is done through
parameter P10 in the "installer confi guration".
The supply water temperature in the fan-coil is acquired through
a remote sensor and can be displayed with 1°C resolution in the
0°C .. 99°C range.
The delivery water sensor does not have to be installed in case the
system does not require it. To enable delivery water sensor related
functions, see the "Cut-off temperature function" section.
In case the room or water temperature falls outside the operating
range, the display shows "Or" (out of range). In case the sensor is
faulty as an open or a short circuit, the display shows "EEE" (error):
in this situation, functions which need the temperature are not
performed.
LXTFF01M-IOM-1511
CUT-OFF TEMPERATURE FUNCTION
The cutoff temperature function is used to inhibit the fan operation
whenever, in heating mode, the delivery water is not hot enough.
In order to accomplish this function a delivery water sensor must
be wired, alternatively, a bimetallic thermostat can be wired to the
same terminals. In case the delivery water sensor is used, the
"water hot enough" threshold is defi ned on parameter P22. In case
this function is not needed, parameter P22 can be set to a very
low value (0).
In case a bimetallic thermostat is used for this function, parameter
P07 must be set to the value "2": in this case the fan operation will
be enabled only when the bimetallic contact is closed.
When this type of bimetallic thermostat is used the water
temperature cannot be displayed, nor the automatic changeover
function can be performed. Please refer to the section "Installer
Confi guration" to set the parameters related to the above described
functions.
The cut-off temperature function is also available in cooling mode.
In this case the fan operation is inhibited when the water delivery
is not suffi ciently cold, according to the threshold defi ned on
parameter P23. In case this function is not needed, parameter P23
can be set to a very high value (99).
When the delivery water temperature is not suffi ciently hot or cold
as per P22 and P23 thresholds, the display shows the "
fan is inhibited and the fan speed symbols fl ash.
ELECTRIC HEATER SYSTEM
The thermostat can be confi gured (P01=2) to manage a system with
an electric heater for heating the room and a valve that regulates
the cool water for cooling the room. Follow the wiring diagram in
Fig. 8 e and f. In this type of system it is suggested to set a delay
on the fan switch-off on P21, so that when the electric heater is
" icon. The
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