Viessmann VITOCAL 300-G PRO Installation And Service Instructions Manual page 38

Preparing for installation
Heat pump cascade: 1-stage/2-stage
C
Interface to the separate cooling
circuit or heating/cooling circuit
H Interface to the heating circuits
or the heating water buffer cylin-
der
P Interface to the primary circuit
W
Interface to the DHW cylinder
Equipment required
Pos. Designation
Heat generator
1 Heat pumps
2 Heat pump control unit
3 Outside temperature sensor
4
LON communication module for cascade control of the lead heat pump I
or
LON communication module for lag heat pumps II to IV
5 (First) secondary pump (fail-safe)
7 Only for 2-stage heat pumps (type BW 302.A090, BW 302.A120,
BW 302.A150, BW 302.A180, BW 302.A250, WW 302.A125, WW 302.A155,
WW 302.A200, WW 302.A250WW 302.A300): Second secondary pump
(fail-safe)
Note
■ Contactor relay required.
■ Size first secondary pump 5 for partial load.
qT (First) primary pump (fail-safe)
wT
Optional: Second primary pump (fail-safe) for stage 2
Note
■ Contactor relay required.
■ Size first primary pump qT for partial load.
eE Cylinder loading pump (DHW side, fail-safe)
Electrical installation scheme
For a summary of electrical connections,
see from page 53 and separate "Con-
nection and wiring diagram".
38
(cont.)
I Lead heat pump in the heat
pump cascade (1-stage or
2-stage)
II to IV Lag heat pumps 1 to 3 of the
heat pump cascade (each 1-
stage or 2-stage)