Viessmann VITOCAL 300-G Installation And Service Instructions Manual page 56

Preparing for installation
System example 2
Pos. Description
Natural cooling function (NC)
Note
All required components (with a suitably designed plate heat exchanger)
for the cooling circuit must be provided on site.
iQ Three-way diverter valve
Note
When using a three-way diverter valve without spring-loaded return, at
contact gS2
terminal strip X3, page 225).
iW
Secondary cooling circuit pump
iE Contact humidistat
iR Primary cooling circuit pump
iT Mixer motor - three-way mixer
iZ Frost stat
iU Extension kit for NC
iI Extension kit for heating circuit (cooling circuit) with mixer
iO Motorised two-way valve, normally closed
Note
When using a two-way diverter valve without spring-loaded return, at con-
tact gS1 (from pos. iU) "L1" must be connected (see for example terminal
strip X3, page 225).
Heating circuit without mixer (A1)
oP Radiator heating circuit
oQ Vitotrol 200 remote control
oZ
Heating circuit pump
Heating circuit with mixer (M2)
uP Underfloor heating circuit with directly controlled mixer motor
uQ Vitotrol 200 remote control (accessory)
uE Flow temperature sensor
uR Temperature limiter as maximum limiter for underfloor heating systems
uZ Heating circuit pump
uU
Mixer motor - three-way mixer
56
(cont.)
(from pos. iU) "L1" must be connected (see for example