6.4 Pump performance
Figure Pump setting in relation to pump performance shows the
relation between pump setting and pump performance by means of
curves.
H
Pump setting in relation to pump performance
Setting
Pump curve
Constant curve or constant
I
speed I
Constant curve or constant
II
speed II
Constant curve or constant
III
speed III
Radiator heating mode (propor-
tional-pressure curve)
Underfloor heating mode (con-
stant-pressure curve)
18
I
Function
The pump runs at a constant speed and consequently on a constant curve.
At speed I, the pump is set to run on the minimum curve under all operating conditions.
The pump runs at a constant speed and consequently on a constant curve.
At speed II, the pump is set to run on the intermediate curve under all operating conditions.
The pump runs at a constant speed and consequently on a constant curve.
At speed III, the pump is set to run on the maximum curve under all operating conditions. Quick
venting of the pump can be obtained by setting the pump to speed III for a short period.
The duty point of the pump will move up or down on a proportional-pressure curve, depending
on the heat demand in the system.
The head (pressure) is reduced at falling heat demand and increased at rising heat demand.
The duty point of the pump will move out or in on a constant-pressure curve, depending on the
heat demand in the system.
The head (pressure) is kept constant, irrespective of the heat demand.
III
II
Q