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00BNO9061-L
VARMAX -
Installation, Use and Maintenance
4.11. Hydraulic connection
The presence of an integrated irrigation pump in the boiler and an
intelligent control logic enables optimal operation up to IUP/30 (IUP =
Instant Useful Power expressed in Th/h - 1Th/h = 1.163 kilowatts).
Below this throughput of IUP /30, the boiler will continue to operate, but
will gradually lose power (boiler stops below IUP /46).
In connector sleeves 3 and 4, there is no minimum throughput constraint
on the condenser.
In the main heat exchanger, as in the condenser, you must ensure
that you never exceed the throughput prescribed in section 3.4 (boiler
nominal useful power / 10).
Sizing the pipes connecting the boiler to the installation must be done
carefully, to minimise the pressure losses and so avoid oversized circulating
pumps.
In some cases the diameter of the connection pipes will be greater than the
diameter of the boiler tappings. The diameter can then be usefully increased
after the union connectors, the stop valves, and/or the hydraulic balancing
valves.
VARMAX boilers are equipped with the following elements:
• main exchanger drain valve,
• condenser drain valve.
It is mandatory to
fi
t the boiler and its installation with the following elements:
• isolating valves on the
fl
ow and return tappings,
• an expansion vessel,
• an ef
fi
cient bleed device,
• a safety valve set to 6 bar,
• A shut-off on the boiler's
fi
ll circuit in relation to the main supply.
VARMAX boilers are available with 2/3 tappings or 4 tappings. It is not
possible to transform a version with 2/3 tappings into a version with 4
tappings and vice versa.
4.11.1. Boiler with 2 or 3 tappings
2 tappings
If all the circuits have the same return temperatures,
the return tapping located in the lower part must
be used.
U0501961-#
Flow
fi
gure 24 - Connection with 2 tappings
Clamp obstructing
2
nd
return
Return
