ELECTRICAL CONNECTION
• To access the unit's electrical panel, remove the air grille
and remove the electrical box cover, as shown in Figure 1.
1
Important note: Please ensure the cable of the main
powers supply is longer than 500 mm from the control
box terminal block. This is to ensure the control box can
be slide out easily during maintenance activities.
• Connect the power cables to terminal box connectors in
accordance with the wiring diagram and tighten firmly.
• Wiring diagrams have to be made by skilled installer.
Install the water probe (provided in wall-control kit) in
correspondence of delivery hydraulic pipe. Water probe
has to detect exact water temperature of the hydraulic
circuit. Install properly water probe with conductive
paste.
In case of valve unit installation, place water probe on
valve unit's pocket.
In case of 4-pipes installation, place water probe in cor-
respondence of heat coil (or heat valve unit's pocket).
Connection instruction
Perform electrical connections in accordance with laws
and regulations in force in the country concerned.
Always disconnect the electrical power supply before
opening the unit.
• Before installing fan coil make sure the rated voltage of
the power supply is 230V - 50 Hz.
• Make sure that, in addition to supplying the working cur-
rent required by the fan coil, the mains electrical supply is
also able to supply the current necessary to operate other
household appliances present.
• Maximum current absorbed by hydronic cassette is report-
ed in TECHNICAL DATA TABLE.
Power supply, control and valve wiring
The fan coils feature a board with screw terminal block for
connecting the wires from the wall-mounted controller and
the valves. The board has a terminal block for connecting
the power supply, speed management, valve control and
safety device.
The unit must always be earthed.
• Upstream of the unit, fit an Omni polar switch with mini-
mum contact distance of 3 mm.
• The minimum cross section of the electric wires is 0.75
mm
2
. Each terminal accommodates two wires of the same
cross-section (maximum 1.5 mm
Electrical characteristic
• The motor is protected by a thermal contact integrated in
the winding. It stops the motor if overheating occurs and
starts the motor again automatically after it has cooled
down.
• The fan coil is provided with a terminal board for the con-
nection of the electrical feeding, for the fan speed control
and for the connection with the safety device
• The installer has to provide input connection through
access provided on the sides of the unit, fixing the wires
and taking care not to pinch them.
Multiple connection
Only one fan coil can be connected to the control unit. Refer
to multiple connection wiring diagram and to the following
table
Model
Size
606
706
a-CHD
1108
2209
Drain pump
On cooling mode, the electronic board installed on the unit,
controls and runs the condensate drain pump. A level con-
trol system inside the unit starts the drain pump. In case the
internal condensate level reaches the safety limit, the supply
of the water to the valve is stopped. The safety relay has a
deviation contact and allows a remote alarm signal.
Installation
2
).
MTW
ATW
20
15
20
15
20
15
20
15
21
EN