26
Connection of the outdoor humidity probe (optional)
The outdoor humidity probe (optional), necessary for the enthalpic 
and thermo-enthalpic free-cooling, must be installed on-site, on 
the hood of the fresh air intake.   
■ Open the case by turning the top cover anticlockwise (fi g1).
■ Fasten the rear of the sensor case to the side panel of the hood 
(use the screws supplied together with the probe) placing the 
screws in the holes provided (fi g.2).
■ Make sure that the screws that hold the board protective cover 
are fastened tightly (fi g.3).
■ Close the sensor by turning the cover clockwise (fi g.4).
8 - ELECTRICAL CONNECTION
- 1 to 4 RS485 probes (connector 
J10): with AWG20 section cable, 
single braided pair preferably 
shielded with drain wire + Power 
supply 24 Vac (2 wires).
• Temperature: 
  S21 to S24.
• Temperature + humidity: 
  S31 to S34.
Note: in the case of more than one 
probe, connection of the probes 
in series, in the RS485 network. 
Please, refer to the control manual.
S5a
105
B5 (J3)
106
Electric
panel
NTC NTC
S21 (T)
S31(T+H)
+(G) (G0)
Tx
Rx-
Tx
Rx+
GND
Electric
panel
B10
110
No1
111 112 113 114
24Vac
AWG20
RS485
network
 (fi g.1)
 (fi g.2)
 (fi g.3)  (fi g.4)
■ This probe must be fastened to the panel or the wall of the room 
to be conditioned, at ca. 1.5 m height.
Electrical connection
■ Make the electrical connection according to the unit confi guration:
- NTC Probe S5a: B5 (connector 
J3): with 2 x 1,5 mm
2 
section cable, 
within a maximum distance of 30 
meters.
The installer must feed the W34 cable through the M16 feedthrough 
to connect it in the BOX3, located inside the unit, behind the side 
access panel. 
Electrical connection
Humidity probe position
Outdoor
humidity
probe
W34
BOX3 (teminals)
Black:  35
Brown: 31
Grey:  36
Probe (teminals)
Black:  G+
Brown: M
Grey:  H