Primary And Absolute Filter Disassembly And Replacement; Primary Filter Replacement (3997 - 3997W) - Nilfisk 3997 Betriebsanleitung

3997 - 3997C - 3997W - 3997WC
Primary and absolute filter disassembly
and replacement
When the vacuum cleaner is used to vacuum
hazardous substances, the filters become
contaminated, thus:
■ work with care and avoid spilling the vacuumed
dust and/or material;
■
place the disassembled and/or replaced filter in a
sealed plastic bag;
■ close the bag hermetically;
■ dispose of the filter in accordance with the laws
in force.
Filter replacement is a serious matter. The filter must
be replaced with one of identical characteristics,
filtering surface and category.
Otherwise the vacuum cleaner will not operate
correctly.
Lift up the cover and the primary filter with a tackle, a
crane or a bridge crane of adequate carrying capacity.
Use ropes suitable for the purpose; do not use cables
not intended for this purpose.
The cover must be correctly slinged, using the
suitable eyebolts.

Primary filter replacement (3997 - 3997W)

1. Plug
2. Nut
3. Air tube
4. Eyebolts
5. Closing band
6. Clamp
GB
7. Suction hose
8. Clamp
9. Filter catch clamp
10. Primary filter
11. Filter ring
12. Filter cage
13. Lever
14. Filter cage shaft
15. Connecting rod
16. Motor reducer
C31
WARNING!
WARNING!
WARNING!
Figure 9
Take care not to raise dust when this operation is carried out.
Wear a P3 mask and other protective clothing plus protective
gloves (DPI) suited to the hazardous nature of the dust
collected, refer to the laws in force.
Before proceeding with these operations, turn off the vacuum
cleaner and remove the plug from the power socket.
■ Disconnect the plug (1).
■ Unscrew the nut (2) and release the tube (3) from the
fitting.
■ Remove the suction hose (7) from the cover fitting.
■ Unscrew the clamp (6) and remove the ring (5) that locks
the cover to the filter chamber.
■ Sling the cover using the eyebolts (4) and lift it carefully,
because the star-shaped filter and the shaking cage are
connected to the cover.
Do not rest the cover-star-shaped filter vertically
on the ground, but use suitable supports or rest it
sidaways, as the weight of the cover can damage the
filter and the shaking cage
■ Remove filter to get access to the clamps that fix it to the
shaking cage.
■ Cut clamps (8) to detach the cage, unscrew clamp (9)
and remove it from the edge of the filter (10), remove ring
(11) with seal.
Obtain a new filter with identical characteristics as the
previously one and proceed in the following way:
■ Fit the filter catch (9) and retention ring (11) of the old
filter on to the new one.
■ Insert cage (12) and fix it to the filter using clamps (8),
supplied along with the spare filter.
■ Insert filter inside the filtering chamber.
Before closing cover, check that the filter bags (10) and
bearing case (12) are vertical and not slanting.
Lever (13) fixed to cage (12) operating shaft (14) must be
halfway along its travel in the neutral central position.
Connecting rod (15) fixed to reduction unit (16) must point
downwards. Only in this way will cage (12) cover an equal
travel to the right and left when the reduction unit (16) is
operated, without tightening filter (10).
The filter could be torn and the motor of the reduction unit
burnt out if this is not done.
Before locking ring (5) locking the cover on the filter chamber,
shake the filtering unit by hand in order to remove any small
positioning defects.
Fit ring (5) and clamp (6), refit the suction hose (7), the plug
(1) and the air tube (3).
12
WARNING!
04/2011