Electric Connection - Beretta Mynute LOW NOx 24 C.S.I. Installer And User Manual

ENGLISH
Under the safety valve, install a water collecting funnel with the
corresponding discharge in the event of leaks due to the overpres-
sure of the heating system. The domestic hot water circuit does not
need a safety valve, but make sure that the pressure of waterworks
does not exceed 6 bar. In case of doubts, install a pressure reducer.
Prior to ignition, make sure that the boiler is designed to operate
with the gas available; this can be checked by the message on the
packaging and the adhesive label indicating the gas type.
It is very important to highlight that in some cases the smoke pipes
are under pressure and therefore, the connections of several ele-
ments must be airtight.
ANTI-FREEZE SYSTEM
The boiler is fitted as standard with an automatic anti-freeze sys-
tem that activates when the temperature of the water in the primary
circuit falls below 6 °C. This system is always active, guaranteeing
boiler protection to an outdoor temperature level of -3 °C. To take
advantage of this protection (based on burner operation), the boiler
must be able to switch itself on; any lockout condition (e.g. lack
of gas/electricity supply, or safety device intervention) therefore
deactivates the protection. The anti-freeze protection is also ac-
tive when the boiler is on standby. In normal operation conditions,
the boiler can protect itself against freezing. If the machine is left
unpowered for long periods in areas where temperatures may fall
below 0 °C, and you do not want to drain the heating system, you
are advised to add a specific, good quality anti-freeze liquid to the
primary circuit. Carefully follow the manufacturer's instructions with
regards not only the percentage of anti-freeze liquid to be used for
the minimum temperature at which you want to keep the machine
circuit, but also the duration and disposal of the liquid itself.
For the domestic hot water part, we recommend you drain the cir-
cuit. The boiler component materials are resistant to ethylene gly-
col based anti-freeze liquids.
3.2 Securing the boiler to the wall and hydraulic con-
nections
To fasten the boiler to the wall, use the cardboard template (fig. 11)
in the packaging. The position and size of the hydraulic connec-
tions are indicated below:
R CH return
M CH delivery
G gas connection 3/4"
AC DHW output
AF DHW input
In case of replacement of Beretta boilers from previous type, there
is an adaptation kit of hydraulic connections available.

3.3 Electric connection

The boilers leave the factory completely wired with the power cable
already connected and they only need the connection of the room
thermostat (TA) to be carried out in the specific terminals.
To access the terminal board:
- turn off the system general switch
- undo the fixing screws (A) of the shell (fig. 13)
- move forward and then upwards the shell base to unhook it from
the chassis
- turn the instrument panel upside down
- remove the terminal board cover (fig. 14)
- insert the cable of the possible T.A. (fig. 5)
The room thermostat must be connected as indicated on the wiring
diagram.
Room thermostat input in safety low voltage (24 Vdc).
The connection to the mains supply must be carried out through a
separation device with an omnipolar opening of at least 3.5mm (EN
60335-1, category III).
The appliance operates with an alternating current of 230 Volt/50
Hz and an electrical power of 115W (and complies with the stan-
dard EN 60335-1).
It is compulsory to carry out connection with an efficient earth
circuit, according to national and local legislation.
It is advisable to comply with neutral phase connection (L-N).
The earth wire must be a couple of centimetres longer than
the others.
4
3/4"
3/4"
1/2"
1/2"
Do not use gas and/or water pipes to earth electrical appliance.
The manufacturer declines liability for any damage if the appliance
was not connected to an earth circuit.
Use the power cable supplied to connect the boiler to the
mains power supply.
If the power cable is replaced, use a cable type HAR H05V2V2-
F, 3 x 0.75 mm2, with max. outside diameter 7 mm.
3.4 Gas connection
Before connecting the appliance to the gas network, check that:
- national and local regulations are complied
- the gas type is the one suitable for the appliance
- the piping is clean.
The gas pipe must be installed outdoor. If the pipe goes through
the wall, it must go through the central opening, in the lower part of
the template. It is advisable to install a filter of suitable dimensions
on the gas line if the distribution network had solid particles.
Once the appliance has been installed check that connections are
sealed according to current installation regulations.
3.5 Fumes exhaustion and air suction
For fumes exhaustion, refer to the current local and national
regulations. Always comply with local standards of the Fire
Department, the Gas Company and with possible municipal
dispositions.
The release of combustion products is assured by a centrifugal fan
placed inside the combustion chamber and its correct operation
is constantly checked by a pressure switch. The boiler is supplied
without the flue gas outlet/air suction kit, since it is possible to use
the accessories for appliance with a forced draught sealed cham-
ber that better adapts to the installation characteristics.
It is essential for flue gas release and the restoration of boiler
combustion air to use certified pipes and that connection is car-
ried out correctly as indicated by the instructions supplied with the
flue gas accessories. With only one smoke pipe you can connect
more pieces of appliance provided that every piece of appliance is
sealed chamber type.
"FORCED OPEN" INSTALLATION (TYPE B22P/B52P)
Fumes outlet duct Ø 80 mm (fig. 15)
The fumes outlet duct can be aimed in the most suitable direction
for installation needs. To install follow the instructions supplied with
the kit.
In this configuration, the boiler is connected to the Ø 80 mm
fumes outlet duct by means of a Ø 60-80 mm adaptor.
In this case, the combustion supporting air is taken from the
room in which the boiler is installed, which must be a suitable
and ventilated technical room.
Non-insulated fumes outlet ducts are potential sources of
danger.
When necessary, the flue gas flange must be removed using a
screwdriver as a lever.
The boiler automatically adapts ventilation according to the type of
installation and the length of the duct.
Pipe length
ø 80 [m]
up to 9
from 9 to 18 not installed
CONCENTRIC OUTLETS (ø 60-100) - fig. 16
The boiler has been designed to be connected to concentric outlet/
suction pipes and with the opening for air suction (E) closed (fig.
16). The concentric outlets can be places in the most suitable di-
rection according to room requirements, complying with the maxi-
mum lengths indicated in the table. For installation, follow the in-
structions supplied with the kit. According to the length of the pipes
used, it is necessary to insert a flange, selecting one from those
contained in the boiler (see the following table). When necessary,
24 C.S.I.
Load losses for each
Flue gas
bend (m)
flange (F)
45°
Ø 48
1,2
90°
1,7