Selecting Control Mode - Grundfos TPE2 Notice D'installation Et De Fonctionnement

18. Selecting control mode

System application
Recommended for most heating systems, especially in systems with relatively large pressure
losses in the distribution pipes. See description under proportional pressure.
In replacement situations where the proportional-pressure duty point is unknown.
The duty point has to be within the AUTO
automatically adjusts to the actual system characteristic.
This setting ensures minimum energy consumption and low noise level from valves, which
reduces operating costs and increases comfort.
The FLOW control mode is a combination of AUTO
ADAPT
This control mode is suitable for systems where you want a maximum flow limit, FLOW
The pump continuously monitors and adjusts the flow, thus ensuring that the selected
FLOW is not exceeded.
LIMIT
Main pumps in boiler applications where a steady flow through the boiler is required. No extra
energy is used for pumping too much liquid into the system.
In systems with mixing loops, you can use the control mode to control the flow in each loop.
Benefits
• Enough water for all loops at peak load conditions if you have set each loop to the right
maximum flow.
• The dimensioned flow for each zone, required heat energy, is determined by the flow from
the pump.
You can set this value precisely in the FLOW
throttling valves.
• When the flow is set lower than the balancing valve setting, the pump ramps down instead of
losing energy by pumping against a balancing valve.
• Cooling surfaces in air-conditioning systems can operate at high pressure and low flow.
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:
– sized 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.
operating range. During operation, the pump
ADAPT
and FLOW
ADAPT
control mode without the use of pump
ADAPT
Select this control mode
H
.
LIMIT
.
LIMIT
H
Proportional pressure
H
H
set
H
set
2
Constant differential pressure
H
AUTO
ADAPT
Q
FLOW
ADAPT
Q
Q
Q
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