Grundfos NK Montage- Und Betriebsanleitung Seite 22

6.3 Alignment
6.3.1 General
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
up the pump.
It is important to check the final alignment when the pump has
obtained its operating temperature under normal operating
conditions.
6.3.2 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.
Aligning the pump and motor with a straight-edge ruler
Step
1
2
3
4
22
Action
Make a rough alignment
of pump and motor, and
tighten the screws with
correct torque in the
base frame. See the
table "Tightening
torques".
Make a mark on the
coupling, for instance
with a mark 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
finished. Go to point 8.
S1
Fig. 12 Alignment
Step
5
6
7
8
90 °
90 °
90 °
∅
90 °
S2
Action
Adjust the position of the
motor. Slacken the
screws which fix the
motor.
Place shims with the
required thickness.
Tighten the screws with
correct torque again.
Go to point 3, and check
the alignment once
more.
Check the distance S2
both vertically and
horizontally. See the
table "Air-gap width S2".
If the air-gap width is
within the tolerances, the
alignment is finished.
If not, go to point 6.