English (GB)
14
13. Multi-master function
13.1 Systems with one outlet-pressure sensor
To enable the system to deliver a constant pressure, an
outlet-pressure sensor must be connected to and configured on
at least one of the pumps. The pump with this sensor will function
as master pump and control the system.
If the master pump is switched off or stopped due to an alarm, the
other pumps in the system will stop.
If it is not possible to remove the cause of the alarm on the
master pump, another pump can function as master pump.
Connect the outlet-pressure sensor to one of the other pumps
and configure it with Grundfos GO Remote. The system can now
be restarted.
13.2 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. From factory, the master pump is marked with number 1.
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.
14. Protective functions
It is important that any protective function, for example
dry-running protection or external start/stop that is detected via a
digital input, is connected to and configured on all the pumps with
an outlet-pressure sensor.
If an additional sensor is used, for example for the limit-exceeded
function or setpoint influence, this sensor must also be connected
to all pumps with an outlet-pressure sensor. Alternatively, an
additional sensor per pump with an outlet-pressure sensor can be
installed.
14.1 Dry-running protection
Types of dry-running protection:
• a pressure switch which is factory-fitted to the inlet manifold.
See section
.
• a level switch fitted in a water tank. See section
14.1.1 Pressure switch
As standard, Hydro Multi-E is fitted with an adjustable pressure
switch as dry-running protection. The pressure switch is fitted to
the inlet manifold.
If necessary, adjust the lower switching point by turning screw A
and adjust the upper switching point to a value higher than the
lower switching point by turning screw B. See fig.
.
Fig. 19
Adjustment of switching points
Hydro Multi-E must be protected against dry running.
If the inlet pressure is below the lower switching
point, the system cannot start.
If the pressure switch has stopped the system during
operation due to the inlet pressure being too low, the
inlet pressure must increase to a pressure that is
higher than the setting of the upper switching point
before the system can restart.
Do not set the lower switching point to a value below
the minimum inlet pressure. See section
.
T
M
05
84
36
23
13
Pos.
Description
A
Low pressure SP
B
High pressure SP
A
B
