Selecting Control Mode - Grundfos TPE 2 Series Installation And Operating Instructions Manual

15. Selecting control mode

System
Recommended for most heating systems, especially in systems with relatively large pressure
losses in the distribution pipes. See the 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
valves.
• When the flow is set lower than the balancing valve setting, the pump will ramp 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
– very long distribution pipes
– strongly throttled 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
– 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
– 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 balancing valves.
• Primary circuit pumps in systems with small pressure losses in the primary circuit.
In systems with a fixed system characteristic.
Examples
• one-pipe heating systems
• boiler shunts
• systems with three-way valves
• domestic hot-water circulation.
You can use FLOW with advantage to control the maximum circulation flow.
LIMIT
operating range. During operation, the pump
ADAPT
and FLOW
ADAPT
control mode without the use of throttling
ADAPT
Select this control mode
H
.
LIMIT
.
LIMIT
H
H
H set
H
set
2
Constant differential pressure
H
Constant temperature and constant
differential temperature
H
AUTO
ADAPT
Q
FLOW
ADAPT
Q
Proportional pressure
Q
Q
Q
51