Immergas HERCULES SOLAR 26 1A Manual page 21

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
mixing 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
necessity,(see hydraulic diagram).
The control of the correct mixing is entrusted to an NTC probe
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
STHSC ed 0710
A
B
C
Technical Documentation
(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.
19
Flow rate Litres/h
HERCULES Solar 26 1A