Selecting Control Function - Grundfos MAGNA1 Installation And Operating Instructions Manual

7.2 Selecting control function

System application
In systems with relatively large pressure losses in the distribution pipes and in air-conditioning and cooling
systems.
• Two-pipe heating systems with thermostatic valves and the following:
– very long distribution pipes
– strongly throttled pipe balancing valves
– differential-pressure regulators
– large pressure losses in those parts of the system through which the total quantity of water flows, for
example boiler, heat exchanger and distribution pipe up to the first branching.
• Primary circuit pumps in systems with large pressure losses in the primary circuit.
• Air-conditioning systems with the following:
– heat exchangers, fan coils
– cooling ceilings
– cooling surfaces.
In systems with relatively small pressure losses in the distribution pipes.
• Two-pipe heating systems with thermostatic valves and the following:
– dimensioned for natural circulation
– small pressure losses in those parts of the system through which the total quantity of water flows,
for example boiler, heat exchanger and distribution pipe up to the first branching or modified to a
high differential temperature between flow pipe and return pipe, for example district heating.
• Underfloor heating systems with thermostatic valves.
• One-pipe heating systems with thermostatic valves or pipe balancing valves.
• Primary circuit pumps in systems with small pressure losses in the primary circuit.
You can also set the pump to operate according to the maximum or minimum curve, like an uncontrolled
pump:
• Use the maximum-curve mode in periods in which a maximum flow is required. This operating mode is
for instance suitable for hot-water priority in domestic hot-water systems.
• Use the minimum-curve mode in periods in which a minimum flow is required.
16
Select this control mode
Proportional pressure
H
Q
Constant pressure
H
Q
Constant curve
H
Q