Safety Valve; High Limit Safety Cut-Out; Additional Function For Dhw Heating - Viessmann VITOSOL 100-F SV Technical Manual

Information regarding design and operation
Vitosol-T
Static head in m
Absorber area in m 2
1.51
3.03
4.54
6.06
7.57
9.09
10.60
12.12
15.15

Safety valve

The heat transfer medium is drained from the solar thermal system via
the safety valve if the max. permissible system pressure
(6 bar/0.6 MPa) is exceeded. According to DIN 3320, the response
pressure of the safety valve is the max. system pressure +10 %.
The safety valve must comply with EN 12975 and 12977, be matched
to the heating output of the collectors and be able to handle their max-
imum output of 900 W/m 2 .
Absorber area in m 2 Valve size (size of the inlet cross-section)
DN
40
80
160

High limit safety cut-out

The solar control units Vitosolic 100 and 200 are equipped with an
electronic temperature limiter.
A high limit safety cut-out in the cylinder is required when less than
40 litres cylinder capacity is available per m
ably prevents temperatures above 95 °C in the cylinder.

18.12 Additional function for DHW heating

DVGW W 551 specifies that the total water content must be maintained
at least at 60 °C and the DHW preheating stages must be heated once
every day to 60 °C.
■ Systems with a cylinder capacity, incl. DHW preheating stages, in
excess of 400 l
■ Systems with a pipework capacity in excess of
3 l from the DHW cylinder to the draw-off point
We recommend heating up in late afternoon. This ensures that the
lower cylinder area or the preheating stage is cold again following the
expected draw-offs (evenings and the following morning) and can sub-
sequently be heated up again by solar energy.
VITOSOL
(cont.)
System capacity in l Recom. capacity of the expan-
sion vessel in l
5 21.7
10 25.1
15 28.6
5 22.3
10 25.7
15 29.2
5 23.3
10 23.6
15 29.8
5 26.6
10 27.5
15 31.0
5 27.8
10 31.3
15 32.2
5 28.4
10 31.9
15 32.8
5 29.0
10 32.5
15 33.8
5 30.2
10 33.7
15 37.1
5 32.0
10 35.5
15 37.2
15
20
25
2 absorber area. This reli-
Recom. heat sink
(see page 106)
18 —
18
18
25
25 1.5 m uninsulated pipe
—
40 —
25 Type 21
40 —
—
40 Type 21
50 —
40 Type 21
50 —
40 Type 21
50
80 1.2 m uninsulated pipe
40 Type 21
50
80
40
50
80
Discharge and drain lines must terminate in an open container, capa-
ble of collecting the total capacity of the collectors.
Use only safety valves sized for max. 6 bar/0.6 MPa and 120 °C, which
bear the marking "S" (solar) as part of the product identification.
Note
The Solar-Divicon is equipped with a safety valve for up to
6 bar/0.6 MPa and 120 °C.
Example:
3 Vitosol-F flat-plate collectors, 7 m
DHW cylinder with 300 l cylinder capacity
2
300 : 7 = 42.8 l/m ,
e.g. a high limit safety cut-out is not required.
Note
For detached and two-family houses, this heat-up is recommended,
but not compulsory.
2 absorber area
VIESMANN
155
18