Solar-Heating Systems - Grundfos MAGNA3 Manual

MAGNA3

Solar-heating systems

Fig. 12 Functional drawing of a solar-heating system
Main pumps
Solar-heating systems operate with very low flow rates
compared to other heating systems, however, with
relatively large pressure losses. With a conventional
circulator pump, the flow must be controlled with a
valve resulting in a significantly higher power
consumption. To achieve major reductions in energy
consumption, MAGNA3 is optimized with the
FLOW / FLOW control mode for operation
ADAPT LIMIT
specifically under these conditions.
Ground source heat pump systems (GSHP)
Fig. 13 Ground source heat pump system in a commercial
building
Pos. Description
1 Heat pump
Main pumps
MAGNA3 is optimized for operation as a circulator
pump in a closed-loop pipe system which is buried in
the ground and filled with a mixture of water and
antifreeze agent. MAGNA3 is therefore ideal for large
ground source heat pump systems for commercial
buildings.
MAGNA3 is designed for pumping liquids down to +14
°F (-10 °C). The pump can use all known antifreeze
agent compositions.
It is important to note that all components are highly
energy-efficient. No other circulator pump performs
better in GSHP systems than MAGNA3 with the
FLOW / FLOW control mode.
ADAPT LIMIT
Use the benefit of the inputs and outputs of MAGNA3
to control the pump together with the heat pump.
Installation and commissioning
When installing MAGNA3, no external pressure sensor
or motor protection is required. Installation is simple
thanks to the built-in differential-pressure and
temperature sensor, which enables
proportional-pressure control without the installation of
a sensor in the system.
In systems where a differential pressure is desired at a
certain point of the system, you must install an external
pressure sensor. See
Electrical
Pump selection is based on the required flow and
calculated pressure losses. We recommend that you
do not oversize the pump as it will lead to
unnecessarily high energy consumption.
MAGNA3 features the FLOW
where MAGNA3 has full authority, the need for
external pump throttling valves is eliminated. The
FLOW ensures that the rated flow is never
LIMIT
exceeded.
data, page 34.
function. In circuits
LIMIT
3
13