Unical DUA plus BTN 28 - Electrical Connections

Installation info
19
D.H.W. PRODUCTION
Cold water temperature = 15 °C
Quantity drawn at 14 litres/min
fig. 19
Drawing temperature °C
Quantity drawn in litres
By-Pass CLOSED
By-Pass OPEN
fig. 18
It is possible to adjust the by-pass by
acting onto the adjusting screw (see fig.
18).
D.H.W. (Domestic Hot Water)
Inlet and Outlet and of D.H.W. must be
connected to the relevant ½” connections
of the boiler C and F (see fig. 5).
The pressure in the water mains must be
between 1 and 3 bar (in case of higher
pressure it is necessary to fit a PRV
(Pressure Reducing Valve).
We recommend that the discharge of the
safety valve mounted in the boiler be
conveyed into the sewer.
If this precaution is not taken, activation of
the safety valve may result in flooding of
the room where the boiler is installed.
UNICAL shall not be held responsible for
damage caused by non-observance of this
technical precaution.
The hardness of the supply water affects
the frequency of the cleaning of the heat
exchanger; the opportunity to install a water
softning device depends on the
characteristics of the water it self.
NOTE:
With a water whose hardness is higher
than 20°f the use of a softner is strongly
recommended
60
55
50
45
40
35
0 50 100 150 200 250 300
6
5
2.2.12 - ELECTICAL CONNECTIONS
The electrical connections of DUA plus 30
μtank are shown in the clause ‘’WIRING
DIAGRAMS’’ (par. 2.3 - pag. 20).
The boiler must be connected to
the mains supply at 230 V - 50 Hz. This
connection is to be perfectly done, as
foreseen by the IEC and local rules and
must be earthed.
This fundamental requirement for safety
purposes must be checked; in case of
doubt, ask for a professionally qualified
technician to check the electrical system.
UNICAL disclaims all liability for damage or
caused by failure to earth the system.
Gas, domestic water and central
heating pipes are not suitable for
earthing purposes.
The boiler is supplied with 1.5 m long
3x0,75mm² cord.
PhasePhase
PhasePhase
Phase and
Neutral Neutral
Neutral Neutral
Neutral must
compulsory be connected to
PhasePhase
PhasePhase
Phase and
NeutralNeutral
NeutralNeutral
Neutral of the supply socket.
A double pole switch with a distance
between the contacts higher than 3 mm,
must be installed upstream the boiler to
enable all maintenance operations to be
carried out safely.