Connections On Secondary Side For Two-Stage Heat Pumps - Viessmann VITOCAL 300-G Technical Manual

Design information

Connections on secondary side for two-stage heat pumps

C H
W
qP
qQ
qZ
P
qU
wT
3
8
9
C Cooling interface
H Heating interface
Equipment required
Pos. Description
Heat source
1 Heat pump stage 1
2 Heat pump control unit
3 Outside temperature sensor
5 Circulation pump for cylinder heating (heating water side), heat pump stage 1
6 Secondary pump, heat pump stage 1
9 Heat pump stage 2
qP Secondary pump, heat pump stage 2
qQ Circulation pump for cylinder heating (heating water side), heat pump stage 2
qW Safety equipment block with safety assembly
qE Expansion vessel
qT
Primary pump, heat pump stage 1
qZ Flow temperature sensor, primary circuit
qU Return temperature sensor, primary circuit
wT Primary pump, heat pump stage 2
Two-stage heat pump cascade
A heat pump cascade consists of a lead appliance and up to 3 lag heat
pumps. In a two-stage heat pump cascade, the lead appliance and lag
heat pumps each consist of one heat pump stage 1 and one heat pump
stage 2.
The electrical connection is made at the heat pump stage 1 via KM
BUS at external extension H1 (accessory).
VITOCAL 300-G
(cont.)
6
5
qW
qT
P
2
1 qE
P Primary circuit interface (see primary circuit)
W DHW interface (see DHW heating)
Note
With external extension H1 (accessory), the swimming pool water
heating function can be enabled in addition to the heat pump cascade
connection.
3
VIESMANN
31