28
S
I
U
B
A
C
N276660C
DATA I/O
LED
H4
H2
9.6
9.5
If the B4V642 board is used with electromechanical thermostats,
or with other commercial controllers with water probe, the on-
board probe H2 should not be connected and the fan is
controlled by the remote control.
If on the other hand the controller is not set up for managing the
water probe, this function can be performed by the board, by
connecting the 10 kΩ probe on the battery to the H2 connector
on the board (ref. B).
In this case the board carries out the minimum temperature
function for heating operations and maximum temperature
function for cooling. Therefore, if the water temperature is not
suitable for active operation (above 20°C when cooling, under
30°C when heating) the fan is stopped and the anomaly is
signalled by a single flash + pause of the LED (ref. A).
The discrimination between heating/cooling is actuated via the
Summer-Winter (ref. C) input of the board: leaving it open the
board activates heating, closed activates cooling.
If after having connected the probe it is disconnected or
measures incorrect values the anomaly is signalled by 3 flashes
+ pause of the LED (ref. A) and operation is stopped.
To confirm operation without a probe, turn the power to the
board off and then on again.
This condition is saved by the board for future start-ups.
In any case, as and when the probe is connected, the unit
returns to normal operation with temperature thresholds.
Water probe management with 3-speed thermostat
The LED (ref. A) is off if the CV input is not closed (stand-by
condition).
It turns on when the CV contact is closed and indicates
normal operation.
•
Flashes frequently if the grille microswitch S1 is activated
due to the filter cleaning operation
•
1 flash + pause indicates a fan stoppage alarm due to
unsuitable water (with H2 water probe connected).
•
2 f pause due to a motor alarm (e.g. blockage
caused by foreign objects, faulty rotation sensor).
•
3 f pause indicates a disconnected or faulty
water probe alarm.
LED signals
