Functions; Anti-Cycling; Dry-Running Protection; Frost Protection - Grundfos PM 1 Montage- Und Betriebsanleitung

8. Functions

8.1 Anti-cycling

If there is a minor leakage in the system, or a tap has
not been closed entirely, the unit will start and stop
the pump periodically. In order to avoid cycling, the
anti-cycling function of the unit will stop the pump
and indicate an alarm.
Default setting: The function is enabled.
Enabling and disabling the function
1. Keep [Reset] pressed for 3 seconds until "Power
on" starts flashing.
2. Select whether the function should be enabled or
disabled. Each press on [Reset] will change
between enabled and disabled.
"Pump on" is off when the function is disabled.
"Pump on" is on when the function is enabled.
3. Keep [Reset] pressed for 3 seconds to return to
operation.
Resetting a cycling alarm
If a cycling alarm has been activated, the pump can
be restarted by pressing [Reset].
In case of a very small consumption, the
anti-cycling function may detect this as
Note
cycling and stop the pump inadvertently. If
this occurs, the function can be disabled.

8.2 Dry-running protection

The unit incorporates dry-running protection that
automatically stops the pump in case of dry running.
The dry-running protection functions differently
during priming and operation.
If a dry-running alarm has been activated,
the cause should be found before the
Caution
pump is restarted in order to prevent
damage to the pump.
8.2.1 Dry running during priming
If the unit detects no pressure and no flow within
5 minutes after it has been connected to a power
supply and the pump has started, the dry-running
alarm is activated.
8.2.2 Dry running during operation
If the unit detects no pressure and no flow within
40 seconds during normal operation, the dry-running
alarm is activated.
8.2.3 Resetting of dry-running alarm
If a dry-running alarm has been activated, the pump
can be restarted manually by pressing [Reset]. If the
unit detects no pressure and no flow within
40 seconds after restarting, the dry-running alarm is
re-activated.

9. Frost protection

If the unit is subjected to frost in periods of inactivity,
the unit and the piping system should be drained
before the unit is taken out of operation.
The unit has no draining options, but
Note
mounting the unit in one of the positions
shown in fig. 5 makes draining easier.
Fig. 5 Mounting positions making draining
easier
9