Startup; Non-Self-Priming Pumps; Self-Priming Pumps; Pipe Connection - Grundfos CM Montage- Und Betriebsanleitung

8. Startup

If there is a risk of condensation in the
motor, remove the motor drain plug before
Note
startup and keep the drain hole open
during operation. See fig. 7.

8.1 Non-self-priming pumps

Do not start the pump until it has been
Caution
filled with liquid.
8.1.1 Liquid filling
Warning
Pay attention to the direction of the vent
hole, and make sure that the escaping hot
or cold liquid does not cause injury to
persons or damage to the equipment.
1. Close the isolating valve on the discharge side of
the pump.
2. Open the isolating valve in the suction pipe
completely before starting the pump.
3. Remove the filling plug. See fig. 10.
4. Fill the pump housing and the suction pipe
completely with liquid until a steady stream of
liquid runs out of the filling hole.
5. Fit and tighten the filling plug.
6. Start the pump and slowly open the discharge
isolating valve while the pump is running. This
ensures venting and pressure build-up during
startup.
The discharge isolating valve must be
opened immediately after startup of the
Caution
pump. Otherwise the temperature of the
pumped liquid may become too high and
cause damage to the equipment.
Drain hole
Fig. 10 Position of filling hole and drain hole
If it is difficult for the pump to build up
Note
pressure, it may be necessary to repeat
steps 1 to 6.
Filling hole

8.2 Self-priming pumps

Do not start the pump until it has been
Caution
filled with liquid.
8.2.1 Liquid filling
Warning
Pay attention to the direction of the vent
hole, and make sure that the escaping hot
or cold liquid does not cause injury to
persons or damage to the equipment.
1. Make sure that the discharge pipe is empty and
that the height from the centre of the suction port
to the first tapping point (H
requirements. See section
(self-priming pumps).
2. Open the isolating valves in the suction and
discharge pipes.
3. Open a tap close to the pump so that air can
escape.
4. Remove the filling plug in the pump. See fig. 11.
5. If a filling plug has been installed in the discharge
pipe, remove this plug and use this hole for filling.
Otherwise use the filling hole in the pump.
6. Fill the pump housing and the suction pipe
completely with liquid until a steady stream of
liquid runs out of the filling hole.
7. Fit and tighten the filling plug(s).
8. Start the pump and wait until liquid is pumped. If
you have used the filling hole in the pump, it may
be necessary to repeat steps 1 to 8 to ensure that
the pump is completely filled with liquid.
If connected to a frequency converter, the
Note
pump must run at maximum speed (3450
-1
min ) during startup.
9. If the pump does not operate properly after
several start attempts, see section
finding.
Filling hole
Fig. 11 Position of filling holes and drain hole
The pump is allowed to run for 5 minutes
to attempt to suck liquid. If the pump does
Note
not build up pressure and flow, repeat
steps 1 to 8.
) meets the
1

6.2.2 Pipe connection

12. Fault
Filling hole
Drain hole
11