Grundfos NK Serie Instrucciones De Instalación Y Funcionamiento página 15

7.3 Alignment
7.3.1 General information
When a complete unit is supplied assembled from the factory, the
coupling halves have been accurately aligned by means of foil
inserted under the pump and motor mounting surfaces as
required.
As the pump/motor alignment may be affected during transport
and installation, it must always be checked again before starting
the pump.
It is important to check the final alignment when the pump has
obtained its operating temperature under normal operating
conditions.
Aligning the pump and motor with a straight-edge ruler
Step
1
2
3
4
Action
Make a rough alignment
of pump and motor, and
tighten the screws in the
base frame to the
correct torque. See the
table Tightening torques
on page 18.
Make a mark on the
coupling, for instance
with a marker pen.
Hold a straight-edge
ruler against the
coupling, and determine
the inaccuracy, if any,
with a feeler gauge.
Turn the coupling 90 °,
and repeat the
measurement with
straight-edge and feeler
gauge. If the measured
values are less than 0.2
mm, the alignment is
complete. Go to step 8.
7.3.2 How to align the unit
It is very important that the pump/motor alignment is carried out
correctly. Follow the procedure below.
The values for ∅ and S2 can be found in the following table. The
value for S1 is 0.2 mm.
S1
Fig. 12 Alignment
Step
5
6
7
8
90 °
90 °
90 °
∅
90 °
S2
Action
Adjust the position of
the motor. Loosen the
screws that hold the
motor in place.
Insert shims with the
required thickness.
Tighten the screws to
the correct torque. Go to
step 3, and check the
alignment once more.
Check the gap S2 both
vertically and
horizontally. See the
table Air-gap width S2
on page 18. If the air-
gap width is within the
tolerances, the
alignment is complete. If
not, go to step 6.
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