Connecting The Cooling Circuit - Viessmann VITOCAL 222-G Series Installation And Service Instructions For Contractors

Hydraulic connections
Connecting the primary circuit
!
Please note
The heat transfer medium can cause corrosion
damage to on-site lines and components.
The components and lines used must be resist-
ant to the heat transfer medium. Never use zinc-
plated/galvanised pipes.
1. Equip the primary circuit with an expansion vessel
and safety valve, in accordance with DIN 4757.
Note
The expansion vessel must be approved to
■
DIN 4807. The diaphragms of the expansion ves-
sel and safety valve must be suitable for the heat
transfer medium.
■ The blow down and drain pipes should exit into a
container. This container must be able to hold
the maximum possible expansion volume of the
heat transfer medium.
2. Ensure adequate thermal and anti-vibration insula-
tion where pipes penetrate walls.
3. Connect the primary pipes to the heat pump.
!
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.
4. Insulate pipes inside the building to prevent heat
and vapour diffusion.
5. Fill the primary circuit with Viessmann heat transfer
medium and vent.
Note
Ensure frost protection down to
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
19 °C.
–

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.
(cont.)
19 °C.
–
Connecting the secondary circuit
1. Equip the secondary circuit with an expansion ves-
sel and safety valve on site, in accordance with
DIN 4757.
Fit the safety valve to the on-site line in the heating
water return.
Note
The expansion vessel must be approved to
EN 13831.
2. Connect the secondary lines to the heat pump.
!
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 circuit".
■ Ensure the minimum flow rate, e.g. with an overflow
valve: See chapter "Specification".
Installation instructions "NC-Box"
Installation sequence
19