6.1.4
Mode of operation
6.1.4.1
Automatic control
The closed-loop control mode integrated in the pump is active when the operating
mode is set to
Internal
. The operating mode can be set at DIP switch 1.
DIP switch 1 = ON
Operating mode
External
DIP switch 1 = OFF
Operating mode
Internal
2
1
ON
OFF
Fig. 3: DIP switch (example: single pump in Internal mode)
The pump starts up when the terminal pair RUN is bridged (factory setting) and stops
when the terminal pair is not bridged.
RUN
0V
IN
Fig. 4: Terminal pair RUN
The pump is operated within the control curve for maximum pump power output
P
max
= Q x H (point A, dashed line) and automatically adjusts itself to different output
requirements. The control knob is set to its middle position (see illustration).
H
Q
A
By turning the control knob at the control module the pump power output can be
adjusted manually. By turning the control knob anti-clockwise the pump power
output can be reduced, e.g. in case of flow noises. This means the control curve will
shift towards lower heads.
By turning the control knob clockwise the pump power output can be increased, e.g.
if some radiators remain cold despite hydraulic input. This means the control curve
will shift towards higher heads.
H
Q
H
Q
Control mode function
Closing of thermostatic valves (or similar control devices) reduces the volume flow
rate to be pumped, which also decreases the friction loss in the piping. The pump
control system recognises this event and reduces the pump input power. As the
volume flow rate decreases, the head decreases correspondingly. This ensures smooth
and trouble-free running of the pump at minimised power input.
6 Commissioning/Start-up/Shutdown
22 of 36
Rio-Eco N / Rio-Eco Z N / Rio-Eco Therm N
