gala gar Smart Mig 250/1 Manuel Technique D'instructions page 15

5. ANOMALIES. PROBABLE CAUSES. POSSIBLE SOLUTIONS.
SYMPTOM. ANOMALY.
GENERAL PROBLEM
NOTHING WORKS.
LIMITER TRIPS
ALTHOUGH THE MACHINE IS
CONNECTED AND WITH THE
SWITCH ON, THERE IS NO
REACTION WHEN PRESSED
WHEN THE GUN IS PRESSED,
ALTHOUGH WIRE COMES OUT,
THE CONTACTOR DOES NOT
WORK OR/AND THERE IS NO
SHIELDING GAS.
WHEN THE SHIELDING GAS IS
RELEASED IT CONTINUES
FLOWING.
WHEN FINISHING WELDING
THE WIRE REMAINS STUCK TO
THE TORCH CONTACT TUBE.
WHEN FINISHING WELDING
THE FINAL WIRE LENGTH IS
VERY GREAT.
THE EQUIPMENT DOES NOT
WELD CORRECT.
"IT ADJUSTS BADLY"
THERE ARE MANY PROJECTIONS
IN THE WELDING PROCESS
SPECIALIZED PERSONNEL MUST CARRY OUT ANY WORK ON THE EQUIPMENT
BOTH AT THE BEGINNING AND END OF A REPAIR CHECK THE EQUIPMENT INSULATION LEVELS.
DISCONNECT THE ELECTRONIC BOARDS WHEN MEASURING THE INSULATION
The insulation-measuring device will have 500 V DC and will be applied to the following points of the circuit:
- Rectifier input-earth: Ra> 50 Mohms
- Rectifier output-earth: Ra> 50 Mohms
- I2 Switch - Rectifier output: Ra> 50 Mohms
- Control circuit - Earth: Ra> 50 Mohms
In the event that lack of insulation is observed it is likely that this is due to the accumulation of metal dust on the inside of
the equipment
:
BOTH AT THE BEGINNING AND END OF A REPAIR, BLOW THE INSIDE OF THE EQUIPMENT WITH
COMPRESSED AIR
.
Smart Mig 250/1. Instructions manual.
PROBABLE CAUSE.
The machine has no voltage in one or all
its vital elements.
Magnetothermal switch has low gauge for
the case. There may be a short circuit,
which is what causes the limiter to trip.
Problem in the internal connection.
The thermal protection has "blown". Pilot
F illuminated.
Faulty electronic card.
Failure of the pistol switch which does
not make perfect contact.
Voltage does not reach the Contactor
or/and solenoid valve.
There is impurity in the inside chamber of
the solenoid valve which prevents the
piston from closing completely.
The contactor has a very high opening
delay.
The contactor has a very low opening
delay.
Low effective welding voltage. Output
wave not correct.
The welding wire has a mechanical
resistance at the outlet, which prevents it
from having a regular speed.
Unsuitable shielding gas.
POSSIBLE SOLUTION.
1. Make sure there is voltage at the entry to the
machine, if not the tapping must be changed. It
is advisable to see if any magnetothermal has
"blown".
2. Check that fuse T of the power source is not
open.
3. The machine panels must be removed
testing the logical points of the electrical
diagram.
Change the magnetothermal for another
larger gauge one. It is important for the
magnetothermal switch to have a characteristic
slow type curve.
Check that the internal connections are corrects.
Wait until the machine cools down correctly.
Do not disconnect the machine.
Replace the electronic card.
Change the gun microswitch.
It must be established whether the fault comes
from the electronic board or if it is an electrical
connection fault.
Check that the contactor coils or/and solenoid
valve are not open.
Dismantle and clean the electrovalve.
Suitably regulate the post-flux potentiometer of
the electronic card.
Suitably regulate the post-flux potentiometer of
the electronic card.
Check that there is not a phase failure in the
supply power.
Check that the electrical contact elements of the
welding circuit are correct: Welding mass, rusty
or very dirty surfaces, contact nozzle with
greater diameter than the wire, etc.
Test the electrical diagram of the power source:
input and output voltages to the rectifier.
Examine the welding gun. Blow the inside
(cable) with compressed air.
When welding normal steels we advise the use
of a gas mixture Ar-CO2.
15
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