English (GB)
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8.6 Inspection and adjustment of impeller clearance
The correct axial clearance is 0.7 mm ± 0.2. Reset the clearance
if it is 0.7 mm or more. The method for resetting the clearance is
different for submersible pumps, installation types S, C and ST,
and for dry-installed pumps, installation types D and H. For dry-
installed pumps there are two methods.
All methods are described here.
8.6.1 Submersible pumps, installation types S, C and ST
Submersible pumps have a separate, adjustable pump inlet cover
which may be shaped as an inlet bell. When the pump is installed
or pulled out of the pit for service, locate the six fastening screws
of the inlet cover and the three set screws.
Use a feeler gauge to check the clearance between the impeller
and the inlet cover all around the perimeter of the inlet opening.
See fig. 10.
Fig. 10 Impeller clearance adjustment
8.6.2 Dry-installed pumps, Installation types D and H
Proceed as follows:
1. Loose the six fastening screws and close the impeller
clearance by tightening the three set screws. Tighten the
screws diagonally to move the inlet cover evenly.
2. Measure the distance "L" between inlet cover and pump
housing at three points next to the set screws, using feeler
gauges or callipers, and make a note of the distance.
3. Loosen the set screws and draw back the inlet cover by
between 0.5 and 0.9 mm using the six fastening screws
(approx. one 270 ° turn of an M12 fastening screw) and the
distance "L" as reference. See fig. 11.
4. Tighten all set screws and check that the distance "L" at the
three reference points is stable at the new value.
Fig. 11 Impeller clearance adjustment
8.7 Electrical measurements
In case the cable is damaged, measure from the cable terminal
with the cable disconnected.
Connections in terminal boards are accessible by hand once the
motor has been removed. See section 9. Dismantling and
assembly instructions.
8.7.1 Checking the internal motor control devices
1. Connect tester (test bell, test lamp, etc.) to leads P1 and P2 (1
and 2).
2. If tester functions (bell rings, lights come on) the control circuit
is closed and intact.
8.7.2 Checking the earth connection
1. Connect one tester to the earth lead (yellow-green wire).
2. Connect second tester to the pump body.
3. In case the tester functions, the earth connector is in order.
In case the tester doesn’t function, the earth connector is
faulty and must be repaired.
It is not possible to adjust the clearance of SV
pumps.
You can check the impeller and pump housing for
wear only.
TM05 1916 3911
Do not use too much force when tightening the
fastening screws as this may damage the bearings.
The movement is usual 1 to 3 mm.
Set screw
0.7
Fastening screw
Fastening screw
TM05 1915 3911
DANGER
Electric shock
Death or serious personal injury
- The pump must not be connected to the mains if
the earth connections is not intact.
Do not connect the tester to the cooling jacket, if any.
Set screw
0.5 - 0.9
Fastening screw
Fastening screw
L
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