Installation manual
200
8.12.9
8.12.9 Parallel Connection of Heat Pumps
Parallel connection of heat pumps
A higher heat consumption can be met by connecting heat
pumps in parallel. Different heat pump types can be used
depending on the need. Large systems with more than three heat
pumps switched in parallel are normally switched and
disconnected using a higher-level load management system.
A parallel connection of heat pumps is also possible without a
higher-level regulation through the existing heat pump manager:
The same heating curves are set for all heat pump
managers
Using the “Hotter” and “Colder” arrow buttons, the second
heat pump is set so that a difference in the return set
temperature of 1K is achieved.
The heat pump to which the domestic hot water preparation
is connected, has the lowest setpoint and, if required, it
controls a second heat generator.
In systems with swimming pool water preparation the return
flow sensor in the heating circuit must be switched to an
additional sensor during swimming pool water preparation.
Regulation using higher-level load management
systems
The higher-level regulation must have a floating switch output
per heat pump compressor. The following solution is
recommended for a parallel connection:
1) The heat pump managers of both heat pumps are set to
fixed-setpoint regulation with maximum required return set
temperature. This leads to the automatic connection of the
second compressor in case of high heating needs.
2) The outputs ID1 and ID4 are used for the heating
requirements using one or both compressors
The second compressor is not connected before expiry of the
switch cycle block (20 minutes).
“DHW preparation with thermostat” must be chosen during
preconfiguration. The hot water settings must be such that the
domestic hot water preparation is always done using a
compressor (switching to 2nd compressor: -25°C).
The regulation of an existing domestic hot water preparation incl.
pump control must be matched to the external regulation.
Dual differential pressureless manifold
Preconfigu
ration
Setting
Fig. 8.42: Integration diagram for heat pumps connected in parallel, a buffer tank connected in series with two manifolds
without differential pressure and hot water preparation
Heat Pump 1.1 1.2
Operating
mode
Monov
alent
Mono
energy
1. Heating
circuit 1
Yes Yes
2. Heating
circuit 1
No No
Domestic
hot water
preparatio
n
No Yes
Swimming
pool
preparatio
n
No No
Hot water preparation is carried
out by the heat pump only.
With brine-to-water heat pumps
each heat pump has its own
brine circulating pump. A joint
borehole heat exchanger or
ground heat collector system
can be used as heat source.
1%
5
1%
5
11
(
1%
5
0
7
7
7
1%
5
7
1
11
(
7&
1%
11
0
7
1%
5
7
1
1%
5
7
11
0
11
0
Power stage Contact position
0 = heat pump off ID4 open
1 = heat pump on with 1 compressor
ID4 closed
ID1 closed
2 = heat pump on with 2 compressors
ID4 closed
ID1 open