7. Control functions
•
Cascade control
•
constant pressure via integrated speed control
•
pump alternation
•
multimaster function
•
Grundfos Eye.
7.1 Cascade control
Cascade control ensures that the performance of
the system is automatically adapted to the
consumption by switching pumps on or off and by
changing the speed of the pumps in operation.
The system runs as energy-efficiently as possible
with a constant pressure and only the number of
pumps required.
7.2 Constant pressure
The integrated speed controller keeps a constant
pressure in the pipe system. A pressure sensor
monitors changes in the water consumption and
signals to the speed controller to adjust the motor
speed up or down.
7.3 Pump alternation
Pump alternation ensures that the operating hours
are distributed evenly on the pumps over time.
The pumps alternate automatically, so that the
system starts the available pump with the lowest
number of running hours since the last time the
power was switched off.
7.4 Multimaster function
If the master pump is switched off or stopped due
to an alarm, the next pump will automatically take
over the control of the system.
7.4.1 Master pump in systems with two or
more outlet-pressure sensors
If two or more pumps in the system are configured
with an outlet-pressure sensor, they can all
function as master pumps.
As standard, the pump with the lowest number will
be the master pump. The master pump is marked
with number 1 from the factory.
If master pump 1 is switched off or stopped due to
an alarm, one of the other master pumps will
automatically take over the control of the system.
7.5 Dry-running protection
CAUTION
Pump damage
The pump may need serious repair or
replacement.
‐
If a dry-running alarm has been ac-
tivated, the cause must be found
before the pump is restarted in or-
der to prevent damage to the
pump.
20
The system incorporates dry-running protection
that automatically stops the pump in case of dry
running.
The dry-running protection works differently during
priming and operation.
7.6 Bus signal
The product enables serial communication via an
RS-485 input. The communication is carried out
according to the Grundfos GENIbus protocol and
enables connection to a building management
system or another external control system.
Via a bus signal, you can remote-set operating
parameters, such as setpoint and operating
mode. At the same time, the product can provide
status information about important parameters
such as the actual value of the control parameter,
input power, and fault indications, via the bus.
Contact Grundfos for further information.
If you use a bus signal, the local set-
tings made via Grundfos GO Remote
or the advanced operating panel will be
overruled. In case the bus signal fails,
the product will run with the local set-
tings made via Grundfos GO Remote
or the advanced operating panel.