User Guide

14
9. E-circulator series 2000
9.1 Functions
Most functions can be selected by means of the pump control
panel. However, some functions can only be selected via the
R100 or via bus.
9.1.1 Control modes
The pump can be set to two primary control modes, i.e.
• proportional pressure and
• constant pressure.
Furthermore, the pump can be set to constant curve.
Fig. 20 Controlled and uncontrolled operation
Proportional-pressure control:
The pump head is reduced at falling water demand and increased
at rising water demand, see fig. 20.
Constant-pressure control:
The pump maintains a constant pressure, irrespective of water
demand, see fig. 20.
Constant curve mode:
The pump is not controlled. The curve can be set within the range
from min. curve to max. curve, see fig. 20.
The pumps have been factory-set to proportional pressure, see
section 3.3 Factory setting. In most cases, this is the optimum
control mode, and at the same time it consumes the least energy.
Guide to the selection of control mode based on system type
TM00 7630 3604
Q
H
H
set
H
set
2
Q
H
set
H
Q
H
2
set
H
set
H
H
Q
H
set
H
Q
H
Q
Controlled operation
Uncontrolled operation
Proportional
pressure
Constant
pressure
Constant
curve
System type for instance ... select this control mode
Relatively great head
losses in the boiler, chiller
or heat exchanger circuit
and the distribution pipes
1. Two-pipe heat-
ing systems
with thermo-
static valves
and:
• with a dimensioned pump head higher than 13 ft,
Proportional
pressure
• very long distribution pipes,
• strongly throttled pipe balancing valves,
• differential pressure regulators,
• great head losses in those parts of the system through
which the total quantity of water flows (e.g. boiler,
chiller, heat exchanger and distribution pipe up to the
first branching).
2. Primary circuit pumps in systems with great head losses in the primary
circuit.
Relatively small head
losses in the boiler, chiller
or heat exchanger circuit
and the distribution pipe
1. Two-pipe heat-
ing or cooling
systems with
thermostatic
valves and:
• with a dimensioned pump head lower than 6.5 ft,
Constant
pressure
• dimensioned for natural circulation,
• with small head losses in those parts of the system
through which the total quantity of water flows (e.g.
boiler, chiller, heat exchanger and distribution pipe up to
the first branching) or
• modified to a high differential temperature between flow
pipe and return pipe (e.g. district heating).
2. Underfloor heating systems with thermostatic valves.
3. One-pipe heating systems with thermostatic valves or pipe balancing
valves.
4. Primary circuit pumps in systems with small head losses in the primary
circuit.
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