18
5.
Fill the primary circuit with Viessmann heat transfer
medium and vent.
Note
Ensure frost protection down to at least
–
15 °C.
Viessmann heat transfer medium is a ready-mixed
ethylene glycol-based medium. It contains inhibi-
tors for corrosion protection. The heat transfer
medium can be used at temperatures down to
–
16 °C.
Connecting the secondary circuit
1.
Equip the secondary circuit on site with an expan-
sion vessel and safety assembly in accordance
with DIN 4757.
Install the safety equipment block with safety
assembly (enclosed in EPP box) on the on-site line
in the secondary circuit return.
Note
The expansion vessel must be approved to
EN 13831.
2.
Connect the secondary lines to the pipes of the
hydraulic connection set: See diagram in chapter
"Fitting the primary circuit/secondary circuit con-
nection set".
!
Please note
Mechanically loaded hydraulic connections
lead to leaks, vibrations and appliance dam-
age.
Connect on-site lines so that they are free of
load and torque stress.
3.
Thermally insulate lines inside the building.
Note
■
For underfloor heating circuits, install a temperature
limiter to restrict the maximum temperature in the
underfloor heating system: See chapter "Connecting
a temperature limiter to restrict the maximum tem-
perature of underfloor heating".
■
Ensure the minimum flow rate, e.g. with an overflow
valve: See chapter "Specification".
Connecting the cooling circuit
An NC-Box (accessories) is required for cooling mode.
Connect the heating/cooling circuit or separate cooling
circuit to the NC-Box.
Installation instructions "NC-Box"
Electrical connection
Preparing the electrical connections
Cables
■
For cable lengths and cable cross-sections, see the
following tables.
■
For accessories:
Cables with the required number of cores for exter-
nal connections.
Prepare an on-site distribution box.
Danger
Damaged wiring insulation wiring can lead to
serious injury from electrical current and result in
appliance damage.
Route cables so that they cannot touch very hot,
vibrating or sharp-edged components.
Installation sequence
Hydraulic connections
(cont.)
6153640
Installation
