Electrical Installation Scheme; Heat Pump Cascade: 1-Stage/2-Stage - Viessmann VITOCAL 300-G PRO Installation And Service Instructions Manual

Water/water cascade, 1-stage/2-stage
Equipment required
Pos. Designation
1 Heat pump I:
2 ■ Integral heat pump control unit with LON communication module (ac-
cessory)
■ Integral frost stat, primary circuit
■ Integral flow switch, well circuit
9 Heat pump II:
2 ■ Integral heat pump control unit with LON communication module (ac-
cessory)
■ Integral frost stat, primary circuit
■ Integral flow switch, well circuit
qT 2-way motorised valve, heat pump I (fail-safe)
wR Dirt trap
wT 2-way motorised valve, heat pump II (fail-safe)
wZ
Well pump (suction pump for groundwater, fail-safe; connect to each heat
pump via on-site contactor with MCB/fuse protection)
wU Delivery well
wI Return well

Electrical installation scheme

For a summary of electrical connections,
see from page 53 and separate "Con-
nection and wiring diagram".

Heat pump cascade: 1-stage/2-stage

Type BW 301.A090 to 302.A250 and WW 301.A125 to 302.A300
A heat pump cascade consists of a lead
heat pump and lag heat pumps.
Each lag heat pump has a heat pump
control unit. Both the lead and lag heat
pumps can have 2 stages.
The lead heat pump regulates the oper-
ation of the heat pumps within the cas-
cade.
Preparing for installation
(cont.)
35