Changing The Cartridge Filters(3997C - 3997Wc); Hepa Filter Replacement; Downstream Hepa Filter Replacement; Motor Cooling Fan Inspection And Cleaning - Nilfisk 3997 Manual De Instrucciones

Changing the cartridge filters
(3997C - 3997WC)
Figure 10
1. Tank
2. Coils
3. Air hose
4. Cables
5.
Tube
6. Nuts
7. Venturi unit
8. Screws
9.
Cartridge filters
10. Seal
11. Clamp
12. Closing ring
13. Cock
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.
WARNING!
Before working on the filter unit in any way, shut off
the compressed air supply to the tank (1) and vent off
all the air from this latter through cock (13). Stand well
back to prevent air from blasting into the face.
Disconnect the machine from the electricity and compressed
air sources and proceed in the following way when changing
the four cartridges (9):
■ Unscrew the clamp (11) and remove the ring (12) that
locks the cover to the filter chamber.
■ Remove the cover.
■ Unscrew the nuts that lock coils (2) to the solenoid
valves, leaving them inside the chamber (there will be no
need to disconnect them from the electric cable in this
way).
■ Remove the compressed air supply pipe (3) from the
tank (1).
■ Remove the three wires (4) (neutral - n.open - n.closed)
from the pressure switch. Remember their positions as
the vacuum cleaner will not work if they are inverted
(consult the wiring diagram).
■ Detach condensate discharge pipe (5) from under the
tank.
■ Unscrew nuts (6) that fix the tank to the filter chamber
and then remove the tank.
■ Remove the Venturi units (7) allowing them to turn from
right to left.
■ Unscrew screws (8) and lift the cartridges (9), taking care
not to dislodge the dust that will have deposited on them.
■ Fit the new cartridges (9), and correctly position the
seal (10) in the relative housing on the lower side of the
cartridge (9) fixing flange.
01/2015

HEPA filter replacement

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.

Downstream HEPA filter replacement

1. Nuts
2. Protective casing
3.
Absolute filter
■ Unscrew the four bolts (1) and remove the pretective
casing (2).
■ Remove old absolute filter (3) and put it in a plastic bag,
close the plastic bag hermetically and dispose of it in
accordance with the laws in force.
■ Assemble new absolute filter (3), taking care not to
damage it.
■ Fit the protective casing (2) with the slots pointing
downwards.
■ Lock it retightening the four nuts (1).
If the vacuum cleaner is ATEX variant: Perform galvanic
continuity tests in accordance with the accident-prevention
standards (e.g.: VBG4 and according to DIN VDE 0701
part 1 and part 3).
Standard EN 60335-2-69 prescribes inspections at regular
intervals or after repairs or modifications.

Motor cooling fan inspection and cleaning

Periodically clean the motor cooling fan to prevent the motor
from overheating, especially if the vacuum cleaner is used in
a dusty place.
13
3997 - 3997C - 3997W - 3997WC
WARNING!
Figure 11
[ NOTE ]
GB
C31