Ferroli F24 Installation, Service And User Instructions Manual page 25

3.10 Electrical connection
The boiler must be connected to a single phase 30 V 0 Hz electricity supply with a 3 A max. fuse and a bipolar
switch with contact opening of at least 3 mm fi tted between the boiler and the electricity supply. The boiler must
always be connected to an effi cient earth installation. Under the electrical box, there is a 3 pole terminal board for
connecting the boiler to the mains ( 30 V 0 Hz) and a pole board for connecting a room thermostat (RT). To connect,
undo the screws fi xing the terminal board box and connect the wires, ensuring correct polarity of the terminals. It
should be noted that there is low voltage ( 4 V) between the room thermostat contacts.
When the boiler is connected to an electricity main, it is essential TO OBSERVE CORRECT POLARITIES (LIVE:
brown cable, NEUTRAL: blue cable, EARTH: yellow-green cable).
All wiring must conform to current I.E.E. regulations.
ote: If the power supply cable has to be replaced, use 0.
with a maximum external diameter of
ote When connecting a room thermostat or external timer, do not lin the power supply of these devices
to the switching contacts. The switch contacts must be voltage free. Any mains powered devices must utilise
mains power solely to drive the timer motor.
Applying mains voltage to the switch contacts will irreparably damage the circuit board.
Although this boiler can also be used without a room thermostat, you are recommended to install one
for the following reasons:
reater comfort conditions due to more accurate control of room temperature.
reater energy savings.
3.11 i erential air pressure switch (fi g.
The differential air pressure switch is a safety device which allows the main burner to ignite only after having
verifi ed that the fan is wor ing correctly. If the difference in pressure between the ue gas discharge pipe and the
air inta e pipe is not at least e ual to the minimum pressure switch calibration value, the pressure switch contacts
do not close and the gas valve is thus prevented from opening.
In addition, the electrical circuit of the boiler is designed so that if for any reason the air pressure switch contacts
remain closed when the fan stops, the burner will not start up again.
3.1 hec s
ill the central heating system as described previously (3.0 ) and chec there are no lea s in the domestic hot
water and boiler water circuits. Chec that there are no gas lea s on the boiler or the supply to the boiler. Also
chec that the electrical connections are correct.
3.13 nstalling a room thermostat
To connect the thermostat:
Open the electrical box on the base of the appliance and remove the
3 and 4.
Connect the room thermostat (
mm.
- part 4 )
(fi g. 4 )
) as shown in fi g. 4 .
mm ( 4 0. 0) heat resisting cable only to BS
umper cable between terminals
00