Selection Of Control Mode - Grundfos UPED 50-12 Montage- Und Betriebsanleitung

6.3 Selection of control mode

Systems with specified control mode:
If the control mode (proportional or constant pres-
sure) and the pump head have been specified for the
system in which the pump is to be installed, the
pump should be set as specified. See section
7. Setting the pump. If problems should arise, see
section 8. Fault finding chart.
In systems
for instance ...
with ...
1. Two-pipe
heating sys-
tems with
thermostatic
valves and
with:
relatively great
head losses in
the boiler circuit
and the distribu-
tion pipes
2. Underfloor heating systems and one-pipe heating systems with
thermostatic valves and great head losses in the boiler circuit.
3. Primary circuit pumps in systems with great head losses in
the primary circuit.
1. Two-pipe
heating sys-
tems with
thermostatic
valves and:
relatively small
head losses in
the boiler circuit
and the distribu-
tion pipes
2. Underfloor heating systems with thermostatic valves.
3. One-pipe heating systems with thermostatic valves or pipe balanc-
ing valves.
4. Primary circuit pumps in systems with small head losses in the pri-
mary circuit.
Systems with no specified control mode:
If the control mode and the pump head have not
been specified for the system, (for instance, an
uncontrolled standard pump is replaced by the
UPED pump), it is advisable to use the settings in
the following table and in section 6.3.1 Setting in
connection with pump replacement.
• a dimensioned pump head higher than 4 metres,
• very long distribution pipes,
• strongly throttled pipe balancing valves,
• differential pressure regulators,
• great head losses in those parts of the system
through with the total quantity of water flows (e.g.
boiler, heat exchanger and distribution pipe up to
the first branching) or
• low differential temperature.
• with a dimensioned pump head lower than
2 metres,
• dimensioned for natural circulation,
• with small head losses in those parts of the system
through with the total quantity of water flows
(e.g. boiler, heat exchanger and distribution pipe up
to the first branching) or
• modified to a high differential temperature
(e.g. district heating).
select this con-
trol mode ...
Proportional
pressure
Constant
pressure
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