Function Of Automatic Night Setback; Setting Manual Summer Mode; Dry-Running Protection; Alpha Reader - Grundfos ALPHA2 Series Installation And Operating Instructions Manual

8.2 Function of automatic night setback

Once you have enabled automatic night setback, the pump
automatically changes between normal duty and automatic night
setback. See section
9. Fault finding.
Changeover between normal duty and automatic night setback
depends on the flow-pipe temperature.
The pump automatically changes over to automatic night setback
when a flow-pipe temperature drop of more than 10 to 15 °C
within approx. two hours is registered. The temperature drop
must be at least 0.1 °C/min.
Changeover to normal duty takes place without a time lag when
the flow-pipe temperature has increased by approx. 10 °C.

8.3 Setting manual summer mode

Manual summer mode is available from model C.
In manual summer mode, the pump is stopped to save energy
and only the electronics are running. To avoid liming and blocking
of the pump, the pump is started frequently in a short period. This
is an alternative to shutting down the pump if there is a risk of
lime deposit.
There is a risk of lime deposit in case of a long
standstill period.
In manual summer mode, the pump starts frequently at low speed
to avoid blocking the rotor. The display is turned off.
If any alarms occur during manual summer mode, no alarms will
be shown. When manual summer mode is deactivated again, only
the actual alarms will be displayed.
If the automatic night setback mode is enabled before setting the
manual summer mode, the pump will return to automatic night
setback mode after manual summer mode.
8.3.1 Activating manual summer mode
Activate the manual summer mode by pressing the automatic
night setback button 3 to 10 seconds. See fig. 30. The green light
field flashes quickly. After a short while the display turns off and
the green light field flashes slowly.
Fig. 31 Automatic night setback button
8.3.2 Deactivating manual summer mode
Deactivate the manual summer mode by pressing any of the
buttons. Then the pump returns to the previous mode and setting.

8.4 Dry-running protection

The dry-running protection protects the pump against dry running
during start and normal operation. See section
During first startup and in case of dry-run, the pump will operate
for 30 minutes before displaying the error code E4.
18

8.5 ALPHA Reader

You can use this device to balance the radiators in a heating
system in a fast and safe way.
ALPHA Reader provides safe readout of internal data from the
pump. The data are transmitted to a handheld device. See fig. 32.
Fig. 32 ALPHA Reader
Activating and deactivating the ALPHA Reader mode
If you press [W/m
Reader is either activated or deactivated, depending on the
previous state.
When ALPHA Reader is active, the AUTONight indicator light
flashes rapidly, indicating activity.
You can activate and deactivate the ALPHA Reader mode in all
pump modes.
For further information, see the ALPHA Reader documentation in
Grundfos Product Center on www.grundfos.com.

8.6 High-torque start

If the shaft is blocked and you cannot start the pump, the display
indicates the alarm "E1 - "- -"", with a delay of 20 minutes.
The pump attempts to restart until the pump is powered off.
During the start attempts, the pump vibrates due to the
high-torque load.
9. Fault finding.
3
/h] and holds it for 3 seconds, ALPHA