Oil Check And Oil Change; Inspection And Adjustment Of Impeller Clearance; Inspection Of Impeller Clearance For Pumps In Submerged Installation; Adjustment Of Impeller Clearance For Pumps In Submerged Installation - Grundfos SEN series Montage- Und Betriebsanleitung

8.1 Oil check and oil change

The oil chamber has three screws, A, B and C, for oil drainage, oil
filling and level control, see fig. 11.
Fig. 11 Position of oil plugs on horizontally installed pumps
The screw B is used for the indication of the oil level in the oil
chamber, see fig. 12.
Fig. 12 Position of oil plugs on vertically installed pumps
Proceed as follows:
1. Place the pump in such a position that the screw A is pointing
upwards.
When slackening the screw A of the oil chamber,
note that pressure may have built up in the chamber.
Do not remove the screw until the pressure has been
fully relieved.
2. Place a clean container under the pump to collect all the
drained-off oil. Slacken the screw B pointing to the side and
observe the oil level. The drained-off quantity of oil indicates
whether the lower mechanical shaft seal is leaking, which may
be normal.
3. Turn the pump or remove the screw C and allow all the oil to
drain from the chamber into the container. Pour an oil sample
into a glass container and observe the condition of the oil.
Clear oil can be reused.
Emulsified oil must be changed and disposed of.
Note: Used oil must be disposed of in accordance with local
regulations.
Low oil level may indicate that the upper mechanical shaft seal
is defective. Contact an authorized service workshop for fur-
ther overhaul of the pump and repair, if required.
4. Fill the oil chamber with oil through the top hole A until the oil
level reaches the hole B. Replace the O-rings by new rings,
insert the screws and tighten securely.
Use viscosity grade SAE 10 W 30.
ONDINA 917 can be used in temperature class T4
applications only.

8.2 Inspection and adjustment of impeller clearance

Adjustment of the impeller clearance is only relevant for
pumps with channel impellers (SEN1 and SEN2 pumps).
The correct impeller clearance is 0.7 mm ±0.2 mm. The clearance
should be adjusted if it is worn to 1.2 mm or more.
The procedures for adjustment of the impeller clearance are dif-
ferent for pumps in submerged installation and pumps in dry
installation. Both procedures are described in the following.
8.2.1 Inspection of impeller clearance for pumps
in submerged installation
1. Lay the pump flat on a work bench.
2. Locate the six fixing screws securing the pump housing to the
motor and the three adjusting screws, see fig. 13.
3. Check the clearance between impeller and pump housing all
the way round using a feeler gauge.
4. Turn the impeller by hand and check at several points, see
fig. 14.
Fig. 13 Adjustment screws for impeller clearance
Fig. 14 Meassuring the impeller clearance
If the impeller clearance needs adjustment, follow one of the pro-
cedures described below.
8.2.2 Adjustment of impeller clearance for pumps in
submerged installation
Procedure:
1. Slacken all fixing screws and adjusting screws between pump
housing and motor.
2. Tap on the pump housing at several points using a rubber mal-
let to loosen the pump housing from the motor.
3. Close the impeller clearance by tightening three of the fixing
screws until the impeller touches the pump housing. Do not
use unnecessary force.
4. Slacken the fixing screws and open the clearance to 0.7 mm
±0.2 mm by tightening the three adjusting screws, see fig. 15.
Check that the clearance is equal all around the suction open-
ing.
Fig. 15 Impeller clearance for pumps in submerged installation
5. Tighten all fixing screws and check that the clearance is still
equal all around the suction opening.
Adjusting
screw
Fixing
screws
15