Start-Up And Operation; Priming; Checking The Direction Of Rotation; Starting - Grundfos MTB Serie Manual Del Usuario

8. Start-up and operation

Warning
Do not start the pump until the coupling
guard is fitted.
Do not start the pump until it has been
Caution
filled with liquid and vented.

8.1 Priming

The suction pipe and the pump must be filled with
liquid before the pump is started.
If the liquid level is below the pump inlet or there are
airlocks in the suction pipe, proceed as follows:
1. Close the discharge isolating valve and open the
isolating valve in the suction pipe.
2. Loosen the air vent screw.
3. Remove the plug from one of the pump flanges,
depending on the pump location.
4. Pour liquid through the priming port.
5. Make sure the suction pipe and the pump are
completely filled with liquid.
6. Replace the plug and tighten securely.
7. Tighten the air vent screw.
The suction pipe can to some extent be filled with liq-
uid and vented before it is connected to the pump. A
priming device can also be installed before the
pump.

8.2 Checking the direction of rotation

Do not start the pump to check the
direction of rotation until it has been
Caution
filled with liquid.
Do not remove the motor from the
pump to check the direction of rotation,
Caution
as this may damage the shaft seal.
The correct direction of rotation is shown by an arrow
on the pump housing. See fig. 12. When seen from
the motor fan, the pump should rotate clockwise.
Start the motor only for a short moment.
16

8.3 Starting

1. Before starting the pump, completely open the
suction isolating valve and leave the discharge
isolating valve almost closed.
2. Start the pump.
Sudden, major pressure changes in the
Caution
discharge pipe may damage the pump.
3. Vent the pump during starting by loosening the
air vent screw in the pump head until a steady
stream of liquid runs out of the vent hole.
Warning
Pay attention to the direction of the
vent hole and take care to ensure that
the escaping water does not cause
injury to persons or damage to the
motor or other components.
In hot-water installations, pay special
attention to the risk of injury caused by
scalding hot water.
4. When the piping system has been filled with
liquid, slowly open the discharge isolating valve
until it is completely open.
5. In the event of motor overload, throttle the dis-
charge isolating valve until the motor is no longer
overloaded.
6. If the pump does not build up pressure at once,
stop it and repeat the starting procedure.
Never operate the pump for long
periods if the isolating valve on the
Caution
discharge side is closed.

8.4 Restarting

Do not restart the pump until the pump shaft stands
still.
Backflow of the pumped liquid must not
result in a change in the direction of
Caution
rotation of the pump.

8.5 Stopping

Backflow is stopped by means of the non-return
valve or counter pressure in the pipeline.
Switch off the motor and check that it slows down
smoothly.

9. Storage

All pumps are preserved and can be stored for 6 to
12 months. If the storage time is longer or the pumps
are not in operation, they must receive additional
preservation on the inside.
The storage room must be roofed and well venti-
lated. Avoid temperatures below 0°C and high
humidity.