External Heat Exchanger In Large Solar Thermal Systems; Bypass Circuits To Vitosolic 200 - Viessmann VITOSOL 100-F SV Technical Manual

Solar control units
(cont.)
External heat exchanger for one consumer
Heat exchanger relay switches the solar circuit pump (primary
pump R )
p
S1
S9
1
S2
R2
Rp
– When the start temperature differential "ΔTon" between collector
temperature sensor S1 and cylinder temperature sensor S2 or S4 is
exceeded, the solar circuit pump (primary pump R
pump R4 is switched on.
– When the start temperature differential "HE ΔTon" between heat ex-
changer sensor S9 and cylinder temperature sensor S2 is exceeded,
circulation pump R2 is switched on to heat consumer 1.

External heat exchanger in large solar thermal systems

In large solar thermal systems with long solar lines in areas without
frost protection, a 3-way valve for frost protection of the plate heat
exchanger must be installed. This prevents the flow of cold heat trans-
fer medium into the plate heat exchanger, potentially causing it to
freeze up.
A B C
M
D
A Plate heat exchanger
B Temperature sensor

Bypass circuits to Vitosolic 200

To improve the start-up characteristics of the system or for systems
with several collector arrays, we recommend operation with a bypass
circuit.
VITOSOL
2
S4
R4
) or circulation
p
Heat exchanger relay switches the secondary pump R
S1
R1
1
S9
S2
R
S
R2
R4
– When the start temperature differential "ΔTon" between collector
temperature sensor S1 and cylinder temperature sensor S2 or S4 is
exceeded, solar circuit pump R1 is switched on and the relevant
valve R2 or R4 is opened to heat the consumers.
– When the start temperature differential "HE ΔTon" between heat
exchanger sensor S9 and cylinder temperature sensor S2 is excee-
ded, secondary pump R is switched on to heat consumer 1.
s
C Frost stat
D 3-way valve
s
2
S4
VIESMANN
49
10