Wartung; Lubrication; Shaft Adjustment; Frost Protection - Grundfos DNP series Montage- Und Betriebsanleitung

8. Wartung

Before starting work on the pump, make sure that the
electricity supply has been switched off and that it
cannot be accidentally switched on.

8.1 Lubrication

The pump is maintenance-free.
If the pump is to be drained for a long period of inactivity, remove
the coupling guards and inject a few drops of silicone oil on the
shaft between the motor stool and the coupling. This will prevent
the shaft seal faces from sticking.
Motor Bearings:
As standard, the pump is fitted with a motor without grease nip-
ples. Therefore, the motor bearings are maintenance-free.
If a motor with grease nipples has been fitted to the pump, the
motor should be lubricated with a high-temperature lithium-based
grease.

8.2 Shaft Adjustment

If the motor is removed during installation or for repair of the
pump, the pump shaft must be adjusted after the motor has been
replaced. Adjust the pump shaft as follows:
Slacken the set screw and remove the forked distance piece.
Fit the hexagon socket head screws in the coupling and leave
loose. Raise the coupling and the pump shaft (towards the motor)
by means of a screwdriver or a similar tool, fig. 9.
Fig. 9
Place the distance piece between the motor stool and the cou-
pling. Lower the coupling (towards the pump), fig. 10.
Fig. 10
Tighten the hexagon socket head screws in the coupling to 5 Nm
(0.5 kpm) ensuring that the gaps on either side of the coupling
halves are equal.
Tighten the screws two and two (one side at a time), fig. 11, to the
torque stated below.
Hexagon Socket
Head Screw
M6 x 20
M8 x 25
M10 x 25
72
Torque
13 Nm (1.3 kpm)
31 Nm (3.1 kpm)
62 Nm (6.2 kpm)
Fig. 11
Remove the distance piece and replace with set screw in the hole
provided.
Replace the coupling guards.

9. Frost Protection

Pumps which are not being used during periods of frost should be
drained to avoid damage.
Drain the pump by loosening the air vent screw in the motor stool
and by removing the drain plug from the pump housing, fig. 12.
Care must be taken to ensure that the escaping water
does not cause injury to persons or damage to the
motor or other components.
In hot-water installations, special attention should be
paid to the risk of injury caused by scalding hot water.
Fig. 12
Drain plug
Drain Plug
Do not tighten the air vent screw and replace the drain plug until
the pump is to be used again.