NINFA N LOW NOX 24 MCS
Antifreeze kit for outdoor installation (optional)
In case of installation in a partially protected place, the boiler must be equipped with the special antifreeze kit for pro-
tecting the DHW circuit. The kit comprises a thermostat (A fig. 17) and four electric heaters (R... fig. 17). Connect the
kit to the electronic board as shown in the wiring diagram (see fig. 28). Position the thermostat and heaters on the DHW
circuit pipes as shown in the following diagram.
2.4 Gas connection
B
Before making the connection, ensure that the unit is arranged for operation with the type of fuel available and
carefully clean all the pipes of the gas system to remove any residues that could affect good functioning of the
boiler.
The gas must be connected to the relative connector (see fig. 25) in conformity with current standards, with rigid metal
pipes or with continuous flexible s/steel wall tubing, placing a gas cock between the system and the boiler. Make sure
that all the gas connections are tight. The capacity of the gas meter must be sufficient for the simultaneous use of all
equipment connected to it. The diameter of the gas pipe leaving the boiler does not determine the diameter of the pipe
between the unit and the meter; it must be chosen according to its length and loss of head, in conformity with current
standards.
B
Do not use the gas pipes to earth electrical appliances.
2.5 Electrical connections
Connection to the electrical grid
B
The unit's electrical safety is only guaranteed when correctly connected to an efficient earthing system exe-
cuted according to current safety standards. Have the efficiency and suitability of the earthing system checked
by professionally qualified personnel. The manufacturer is not responsible for any damage caused by failure
to earth the system. Also make sure that the electrical system is adequate for the maximum power absorbed
by the unit, as specified on the boiler dataplate.
The boiler is prewired and provided with a Y-cable and plug for connection to the electricity line. The connections to the
grid must be made with a permanent connection and equipped with a bipolar switch whose contacts have a minimum
opening of at least 3 mm, interposing fuses of max. 3A between the boiler and the line. It is important to respect the
polarities (LINE: brown wire / NEUTRAL: blue wire / EARTH: yellow-green wire) in making connections to the electrical
line. During installation or when changing the power cable, the earth wire must be left 2 cm longer than the others.
B
The user must never change the unit's power cable. If the cable gets damaged, switch off the unit and have it
changed solely by professionally qualified personnel. If changing the electric power cable, use solely "HAR
H05 VV-F" 3x0.75 mm2 cable with a maximum outside diameter of 8 mm.
EN
A
R1
R3
R2
R4
fig. 17 - Positioning of antifreeze thermostat and heaters
cod. 3540R880 - 01/2009 (Rev. 00)
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