Natural Cooling Function (Nc) - Viessmann VITOTRONIC 200 Service Instructions Manual

Heating circuits/cooling circuits
A separate cooling circuit is constantly cooled, irre-
■
spective of the cooling limit.
■ No time program can be set for a separate cooling
circuit.

Natural cooling function (NC)

The NC-Box with mixer (accessories) is required for
the natural cooling function.
The temperature level of the ground is transferred
directly to the cooling circuit. This function is energy
saving, since the compressor is switched off.
Note
■ The natural cooling function is not possible in con-
junction with a heating water/coolant buffer cylinder.
The mixer in the NC-Box will hold the flow tempera-
■
ture above the dew point temperature, particularly
when providing cooling by means of underfloor heat-
ing circuits.
Active cooling function (AC)
In cooling mode the heat pump operates in reverse
(refrigerant circuit reversal).
System without buffer cylinder
The coolant goes directly into the heating/cooling cir-
cuit or into the separate cooling circuit.
Required parameter settings
■ "System scheme 7000" set to "1" or "2"
"Enable buffer cylinder/low loss header 7200" set
■
to "0"
System with heating water buffer cylinder
If the system is equipped with a heating water buffer
cylinder, the heating water buffer cylinder must be
bypassed in cooling mode by means of a hydraulic
bypass circuit. For this, two 3-way diverter valves are
integrated into the system return. These 3-way diverter
valves are controlled via connection 211.5 on the main
PCB: See page 281.
To ensure the minimum system volume for central
cooling, an additional low-volume heating water buffer
cylinder, e.g. Vitocell 100-E, may need to be integrated
into this bypass circuit.
(cont.)
Note
The separate cooling circuit can be switched over to
weather-compensated cooling mode. For this, set
"Room temperature control cooling circuit 7105" to
"0".
With this setting, continuous cooling with a constant
temperature level is not assured. We therefore recom-
mend that you always cool the separate cooling circuit
in room temperature-dependent mode.
The cooling function is controlled via connection 211.5
on the main PCB: See page 280.
Required parameter settings without buffer cylin-
der
■ "Cooling function 7100" set to "2"
■ Selecting the cooling circuit: "Cooling circuit 7101"
/
The compressor is in operation. The cooling capacity
is adjusted by modulating the heat pump.
■ "Cooling function 7100" set to "3"
■ "Cooling circuit 7101" set to "1"
Note
Only 1 cooling circuit is possible.
Required parameter settings
"Enable buffer cylinder/low loss header 7200" set
■
to "1"
■ "Cooling function 7100" set to "3"
■ Selecting the cooling circuit: "Cooling circuit 7101"
Function description
55