Lincoln Electric K3972-3 Operator's Manual page 13

MINIFLEX ® PORTABLE WELDING FUME EXTRACTOR
HIGH AND LOW MODE
In high mode, both motors are working at 100% capacity, extracting
108 CFM (183 m 3 /hr). In low mode, both motors are working at 88%
capacity, extracting 95 CFM (161 m
MANUAL VS. AUTOMATIC START/STOP OPERATION
Use the Automatic Start/Stop feature to extend the life of the carbon
brushes.
In the "auto" setting (see Figure 4, item S2), the unit automatically
starts and stops when the work cable of the welding machine is
positioned in the slot located on top of the machine. See Figure 4.
The unit continues to operate for 15 seconds after welding is
completed before automatically shutting off.
In the manual setting, the unit runs continuously.
FIGURE 4
Worn Carbon Brushes Early Warning System Operation
S2
C
Check Manual
Filter Auto
The worn carbon brushes warning system will inform the user when
90% of the carbon brushes have been used (equals approximately
750 hours motor running time). The unit will indicate this condition
with the Low and High speed LED's blinking alternately with a
sequence of one second on and one second off. This indicator does
not affect the performance of the unit, but merely indicates that
maintenance should be performed.
After the carbon brushes have been replaced, the warning system is
reset by pressing buttons Low/High (S1) and Manual/Auto (S2) simul-
taneously and holding for five seconds. See Figure 5.
FIGURE 5
S3
Check
Filter
3 /hr).
S1
Slot
B
A
Check Brushes
Low
H i gh
S2 S1
Check Brushes
Manual Low
Auto High
Total System Airflow / Static Pressure Control System*
This feature allows the user to check the extraction performance of
the unit. In order to check this performance (Flowcheck), follow the
procedure indicated below:
Flowcheck tests for a minimum airflow of approximately 60 CFM.
Flowcheck Procedure
1. Remove all connected apparatus such as hoses, nozzles, etc. from
inlet and outlet.
2. Switch unit to "On", main switch O/I.
3. When unit starts running press and release the Low/High (S1)
button on the panel until the unit stops running.
4. Press and hold the "Check Filter" (S3) switch for five seconds.
5. Unit will automatically start in "High" speed mode and runs for
about 10 seconds.
6. The software checks the static pressure switch S4 (not visible,
switch is mounted on the circuit board).
7. When S4 = "open", unit stops and goes to "Off" mode and the
"check filter" LED remains off. This indicates that the system
airflow is acceptable (above 60 CFM).
8. When S4 = "closed", unit stops and goes to "Off" mode and the
"check filter" LED flashes with the frequency of one second on /
one second off. This indicates that the extraction volume is less
than 60 CFM.
9. Reset by pressing and holding S2 and S3 for five seconds.
In the case that the indicator communicates that the unit is extracting
less than 60 CFM, proceed as follows to find the filter resistance that
is causing this low airflow:
A. Check condition of pre-filter (Perform Flowcheck Procedure
without pre-filter to check if this is the cause of the low airflow).
Recommended Action: Wash or replace if necessary.
B. Check condition of the main filter (Perform Flowcheck Procedure
without main filter to check if this is the cause of low airflow).
Recommended Action: Replace if necessary.
C. Check condition of the HEPA post filter (Perform Flowcheck
Procedure without HEPA post filter to check if this is the cause of
the low airflow).
Recommended Action: Replace if necessary.
13
OPERATION