Immergas HERCULES SOLAR 26 1A Manual page 25

Technical Documentation
bar and increased by 0.1 bar for every metre of the distance
present between vessel and solar collector however not exceed-
ing the value of 3.5 bar.
Solar safety valve (15).
Prevents the safety pressure in the solar circuit from being
exceeded (6 bar).
It is assembled on the solar circulation unit.
It is good practice to fit the safety valve drain to a container
(can) that can contain a volume of fluid at least equal to the
content of the solar collector. In fact it is not possible to drain
the solar glycol directly to the drains.
Solar pump unit (4).
It is a pump that allows circulation of the fluid inside the solar
circuit. It must contrast the head losses determined by the
resistance offered by the pipes on passage of the fluid, the head
losses of the storage tank unit heat exchanger (coil), of the solar
collector and the other components present in the solar circuit.
It can be adjusted on different speed in a way to obtain a heat
carrying fluid speed between a value of 0.5 - 0.9 m/s.
A flow rate adjuster is present at the input to the pump to
be regulated in order to allow a flow rate of the fluid suitable
to guarantee excellent heat exchange of the solar system (see
next page).
A thermometer (14) is present on the pump output to allow
to measure the temperature of the fluid, which also acts as an
interception cock (see next page).
Solar probe (8).
Allows the integrated P.C.B. to detect the temperature of the
water contained in the lower part of the storage tank unit where
solar coil heat exchange takes place.
It is inserted inside a bulb-holder in contact with the external
wall of the boiler.
3/4" thermostatic mixing valve (17).
It is an adjustable mixing valve from 42 to 60°C positioned at
the outlet of the hot water storage tank in order to guarantee
that the water is distributed towards the utilities at the desired
temperature.
High temperatures can be reached in solar systems.
The main functions of the mixer are:
- to keep the temperature of the water to be sent to the utilities
constant at a fixed value.
- prevent burns hazards by regulating the temperature of the
mixed water sent to the utility to reasonable values (e.g.
between 42 and 48°C).
- to allow extended use of the water stored at a high tem-
perature through time, delivering "attenuated" water to the
utilities.
STHSC ed 0710
Technical Documentation
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HERCULES Solar 26 1A