Setpoint Influence; Temperature Influence; Bus Communication - Grundfos MAGNA3 Montage- Und Betriebsanleitung

Alarm
•
The signal relay is activated together with the red indicator
light on the pump.
Operation
•
The signal relay is activated together with the green indicator
light on the pump.

12.7 Setpoint influence

Navigation
Home > Settings > Setpoint influence
Setpoint influence
External setpoint function
•

Temperature influence.

•
12.7.1 External setpoint function
Range
4-20 mA [0-100 %]
0-10 V [0-100 %]
Control
0-20 % (e.g. 0-2 V)
20-100 % (e.g. 2-10 V)
The external setpoint function is an external 0-10 V or 4-20 mA
signal that will control the pump speed in a range from 0 to 100 %
in a linear function. See fig. 27.
External setpoint function
Before the "
enabled, the analog input must be set to
Note
External setpoint influence
"
See section 4.5.3 Analog input.
rpm
Max.
Min.
0 2
Fig. 27 External setpoint function, 0-10 V
12.7.2 Temperature influence
When this function is enabled in proportional- or
constant-pressure control mode, the setpoint for head will be
reduced according to the liquid temperature.
Temperature influence can be set to function at liquid
temperatures below 80 °C or 50 °C. These temperature limits are
called T . The setpoint is reduced in relation to the head set
max.
(= 100 %) according to the characteristics below.
Setpoint = Min.
Setpoint = Min. ↔ setpoint
" can be
Assist
" via the " " menu.
V
10
H
100 %
H
actual
30 %
20 50 80
T
actual
Fig. 28 Temperature influence
In the above example, T = 80 °C has been selected.
max.
The actual liquid temperature T
to be reduced from 100 % to H
The temperature influence function requires the following:
• Proportional-pressure, constant-pressure or constant-curve
control mode.
• Pump installed in flow pipe.
• System with flow-pipe temperature control.
Temperature influence is suitable for the following systems:
• Systems with variable flows (for example two-pipe heating
systems) in which the enabling of the temperature influence
function will ensure a further reduction of the pump
performance in periods with small heating demands and
consequently a reduced flow-pipe temperature.
• Systems with almost constant flows (for example one-pipe
heating systems and underfloor heating systems), in which
variable heating demands cannot be registered as changes in
the head as is the case with two-pipe heating systems. In such
systems, the pump performance can only be adjusted by
enabling the temperature influence function.
Selection of T
max.
In systems with a dimensioned flow-pipe temperature of:
• up to and including 55 °C, select T
• above 55 °C, select T = 80 °C.
max.
The temperature influence function cannot be
Note
used in air-conditioning and cooling systems.

12.8 Bus communication

12.8.1 Pump number
Navigation
Home > Settings > Bus communication > Pump number
Pump number
A unique number can be allocated to the pump. This makes it
possible to distinguish between pumps in connection with bus
communication.
H
T [°C] Q
causes the setpoint for head
actual
.
actual
= 50 °C
max.
29