LOKERMANN GRAND ARC 400 CEL, User Manual, Page: 21 / 24

S/N Troubles Reasons Solutions
1
Turn on the power
source, and fan works,
but the power light is
not on.
The power light damaged or
connection is not good
Test and repair the inside
circuit of power light Pr3
Power PCB failures
Repair or change power
PCB Pr2
2
Turn on the power source,
and the power light is on,
but fan doesn’t work
There is something in the fan
Clear out
The fan motor damaged
Change fan motor
3
Turn on the power source,
and the power light is not
on, and fan doesn’t work
No input voltage
Check whether there is
input voltage
Overvoltage (Input voltage is too
much or not)
Check input voltage
4 No no-load voltage output There is trouble inside the
machine
Check the main circuit, Pr1
and Pr2
5 No current output in the
welding
Welding cable is not connected
with the two output of the
welder.
Connect the welding cable
to the welder’s output
Welding cable is broken
Wrap, repair or change the
welding cable
Earth cable is not connected or
loosen
Check the earth clamp
6
Not easy to start arc in the
welding, or easy to cause
sticking
The plug loosen or connect not
well
Check and tighten the plug
Oil or dust covered the
workpiece
Check and clear out
Wrong mode selected
Check the MMA selector
switch is selected
7 The arc is not stable in the
welding process
The arc force is too small Increase the arc force
8 The welding current can not
be adjusted
Welding current potentiometer in
the front panel connection not so
good or damaged
Repair or change the
potentiometer
9 The penetration of molten
pool is not enough(MMA)
The welding current adjusted too
low
Increase the welding
current
The arc force adjusted too small Increase the arc force
10 Arc blow
Airflow disturbance Use the shelter from airflow
The electrode eccentricity
Adjust the electrode angle
Change the electrode
Magnetic effect
Incline the electrode to the
opposite way of the
magnetic blow
Change the position of earth
clamp or add earth cable in
the two side of workpiece
Use the short arc operation
11 The alarm light is on
Over heat
protection
Over weldin g
current
Induce the welding current
output
Working time
too long
Induce the duty cycle
(interval work)
Over current
protection
Unusual current
in the main
circuit
Test and repair the main
circuit and drive PCB
(Pr1)