Operation; Normal Operation; Power Supply Failure; Functions - Grundfos PM 1 Manual Del Usuario

If a pressure is not built up in the
system within 5 minutes after start-up,
the dry-running protection will be
activated, and the pump is stopped.
Note
Check the priming conditions of the
pump before attempting to restart the
pump.
Restart the pump by pressing [Reset].
If the pump restarts immediately after
it has been stopped, the isolating valve
used for checking for correct operation
is positioned too close to the PM unit.
A possible isolating valve installed
immediately after the PM outlet must
not be used for checking for correct
Note
operation. The problem will be that the
pipe length between the PM unit and
the isolating valve is too short, and
therefore the expansion of the pipe is
too small. The result is that the
pressure will drop rapidly when the
pump stops.

7. Operation

7.1 Normal operation

When water is consumed in the water supply system,
the PM 1 starts the pump when the starting
conditions of the unit are fulfilled. This happens for
example when a tap is opened which makes the
pressure in the system drop. The unit stops the
pump again when consumption stops, i.e. when the
tap is closed.
7.1.1 Starting and stopping conditions
Starting conditions
The unit starts the pump when at least one of the
following conditions is fulfilled:
• The flow is higher than Q
• The pressure is lower than p
Stopping conditions
The unit stops the pump with a time delay of
10 seconds when the following conditions are both
fulfilled:
• The flow is lower than Q
• The pressure is higher than p
The p , p and Q
start stop min.
section 11. Technical data.

7.2 Power supply failure

In case of a power supply failure, the pump restarts
automatically when power returns and runs for at
least 10 seconds.
The setting of the anti-cycling function will not be
affected by a power supply failure.
.
min.
.
start
.
min.
.
stop
values are shown in

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 cycling and stop the pump
Note
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
Caution
before the 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