Immergas HERCULES Condensing 26 2 E Manual page 23

Technical Documentation
"low temperature" zone (zone 3).
This portion of circuit is also envisioned to operate with floor
panel systems.
It is served by a pump (17) which, via a motorised 3-way mix-
ing valve (14), introduces water into the system at constant
temperature.
To allow this, the 3-way valve (14) is controlled by a P.C.B.
(21) that varies the position depending on the pre-selected
temperature (from 25°C to 50°C).
This setting is made on the boiler control panel.
The temperature of the flow water is obtained by mixing the
high temperature circuit flow water and the low temperature
circuit return water in variable quantities according to neces-
sity, (see hydraulic diagram).
A - Head available to the additional zones (2nd and 3rd zone) at maximum speed
B - Head available to the additional zones (2nd and 3rd zone) at speed 4,5
C - Head available to the additional zones (2nd and 3rd zone) at speed 3
STHCkW ed 04/09
A
B
C
Technical Documentation
The control of the correct mixing is entrusted to an NTC probe
(12) connected to the zones control unit (21).
N.B.: Regarding the wiring diagram, settings, signals, etc. see
the "Zones control unit" technical sheet.
Head available at the low temperature zones.
In functioning condition with mixed systems, the use of several
pumps guarantees a greater total flow rate to the system.
The graphics below represent the trend of the head available
to system zones 2 and 3 at low temperature, depending on
pump speed and with the by-pass inserted between flow and
return.
21
Flow rate Litres/h
HERCULES Condensing Export