Tvfd Valve Closing Time; Maintenance; Service And Maintenance Of Atex Equipment; Separating The Modules - Nederman FlexFilter EX Manual De Instrucciones

7 Flip the stop switch to position "I"
EN
8 Press the reset button. This will bring the TVFD
back into normal operation.
The stop function only stops the com-
pressed air to the TVFD. It does not signal
the control system that the TVFD is inac-
tivated. If the control system activates the
filter cleaning/feed out sequence during
the bag change, the pressure-less air cyl-
inders will trigger a functional alarm. This
can be avoided by using the Nederman "NS
switch".
WARNING! Risk of personal injury
Work inside the TVFD, such as removal of
stuck debris/material is strictly prohibited
during normal operation and bag change.
Cleaning the inside of the TVFD requires
the closing of the main air valve and bleed-
ing of system pressure. Before commen-
cing work inside the TVFD, one must en-
sure that no vacuum or explosive atmo-
sphere is present inside the filter.
Resetting the stop function
To reset the stop function flip the stop switch to 1
(see Figure 21/9) and press the reset button (see
Figure 21/11). After reset, the manometer (see
Figure 21/10) will indicate system pressure and
the TVFD is back in normal operation.

16.3 TVFD valve Closing time

WARNING! Risk of personal injury
Risk of friction heat. Closing time shall not be
set below 1 sec.
A valve that closes fast increases the risk of
personal injuries and the stop function may not
stop the valve from closing.
The closing time of the valves can be set with the si-
lenced exhaust regulators on the back of the TVFD
(see Figure 21/12). The closing time is factory preset
to 5 seconds at delivery. If you adjust the closing time
it may be necessary to adjust the times set in the con-
trol system. The opening speed can not be set.

17 Maintenance

WARNING! Risk of personal injury
Always use proper protective equipment
where there is a risk for exposure to dust.
WARNING! Risk of personal injury
Always use proper lifting equipment and pro-
tective gear.
42
FlexFilter EX
WARNING! Risk of personal injury
Explosion risk! Do not open the connection
box when there is an explosive atmosphere
present.
Fill out the service protocol for all maintenance
performed on the FlexFilter EX.
17.1 Service and Maintenance of ATEX
equipment
To ensure the required level of protection with re-
gards to the equipment category, check the following
points:
• Ensure that the FlexFilter EX is regularly inspected
for damage or malfunction. If the FlexFilter EX is
damaged, it must be shut down and possible explos-
ive atmosphere removed.
• Ensure that no explosive atmosphere and/or dust
layers are present when cleaning, servicing or in-
specting the FlexFilter EX
• Ensure that only Nederman original spare parts are
used.
• Ensure that the FlexFilter EX is not covered with
thick dust layers (> 5 mm). This is prevented by set-
ting up routines for regular cleaning and including
these in the explosion protection document.

17.2 Separating the modules

The Figure 24/A-C show how the rubber sealing rings,
the steel retainer rings and the earth connections
should be assembled. When a used sealing ring is re-
fitted, it no longer has the flat shape as shown in
ure 24/A. The rubber ring has a curved shape. Use e.g.
a screwdriver to fit the edge of the module between
the rubber lips. The steel ring has been fitted, as
shown in Figure
If the collector has been dismantled, ensure that the
rubber sealing rings and the steel retainer rings, keep-
ing the modules together, are correctly reassembled
and that the earth connection is correct (see
ure 25).

17.3 Maintenance schedule

Type of Maintenance
General
Main filter change
Control filter
TVFD valve operation
TVFD stop function
Explosion relief panel
24/C.
Frequency
Once a year
6000 h
6000 h
Weekly
Yearly
3 months
Fig-
Fig-