Inspecting And Adjusting The Impeller Clearance; Dismantling The Pump - Grundfos SE Series Service Instructions Manual

9.6 Inspecting and adjusting the impeller clearance

DANGER
Electric shock
Death or serious personal injury
- Before inspection, make sure that the motor is
switched off and that the main switch is locked in
position 0.
Check the impeller clearance every time service is
carried out to prevent hot surfaces in the hydraulic
parts.
Pressure range
E: Extra-low pressure
L: Low pressure
M: Medium pressure
H: High pressure
S: Super-high pressure
You can inspect the impeller clearance of installation types S and
C directly through the pump inlet.
You can inspect and adjust the installation types D and H with the
pump installed on the base stand and connected to the pipework.
9.6.1 Adjusting the impeller clearance
1. Loosen the set screws by two full turns each.
2. Close the impeller clearance by lightly tightening the fastening
screws diagonally until the impeller touches the pump
housing.
Do not use too much force when tightening the
fastening screws as this may damage the bearings.
3. Loosen the fastening screws to make the correct gap under
the heads of the fastening screws. See fig. 12.
Use the clearance stated in the impeller clearance
table above.
4. Tighten the set screws tightly. For more information about
torques, see section
6. Service
5. Tighten the fastening screws diagonally.
Set screw
Fastening screw
Fig. 12 Impeller clearance adjustment
10
Impeller clearance X
[mm]
0.9 ± 0.1
0.9 ± 0.1
0.6 ± 0.1
0.6 ± 0.1
0.5 ± 0.1
tools.
X
Fastening screw

9.7 Dismantling the pump

Before dismantling the pump
• Switch off the power supply.
• Close the isolating valves, if fitted, to avoid draining the piping
system.
• Disconnect the power supply cable in accordance with local
regulations.
• Note the centre of gravity of the pump to prevent it from
overturning. This is especially important in the case of long
pumps.
9.7.1 Removing the cable
1. Remove the screws (181a) in the cable entry.
2. Slightly lift the cable entry.
3. Using a screwdriver, disconnect the power wires from the
terminal block (176a), and unplug the signal wires. See fig.
13.
Remember to mark the position of the wires carefully.
4. Remove the O-ring (157d).
Do not loosen the lower cable entry (168a) as this
will impair the water tightness.
Signal wires
Power wires
Fig. 13 Illustration of cable wires