Maintenance; Important - Praxair MIG SELECT-300H/4R Guide De L'utilisateur

7 – MAINTENANCE
MIG machines do not need special cares of maintenance, however, it is recommended a periodically inspecting and cleaning
operation. The frequency of this operation must be in according to the environment values of dust or humidity. It must be made as
follows:
- Disconnect the machine from the mains supply.
- Remove lateral covers.
- Clean all dust or humidity with a low pressure and dry air flow.
- Well retighten all electrical contacts (bolts and nuts).
- Also the torch must be periodically inspected. During operation it is subjected to high temperatures. To obtain more information
about torch maintenance it is recommended to read the respective user's manual.
DAMAGE
The machine does not weld when
connected the main switch.
Irregular advance of wire
Porosity in welding melt.
Failure of the welding quality.
The wire feed motor do not run.

IMPORTANT !

DO NOT INSTALL, OPERATE OR MANTAIN THIS APPLIANCE BEFORE READ THIS USER'S GUIDE.
THE EQUIPMENT MUST BE INSTALLED, OPERATED OR MAINTAINED ONLY BY QUALIFIED PERSONS.
MIG SELECT 300H/4R / 350H/4R / 400H/4R / 500H/4R / 650H/4R
CAUSE
Failure on main voltage
Blowed command circuit fuses.
Interruption of the primary cable.
Low pressure of rolls.
Wire guide damaged or in bad condition.
Diameter rolls do not match with wire
diameter.
Wire coil breakage system too much
tightened.
Damaged wire or wire coil.
Gas failure
Solenoid valve blocked
Too much wind blowing through the welding
zone.
Torch nozzle blocked or in bad condition.
Welding piece too dirty, wet or greased.
Defective electrical contact of earth clamp or
torch.
Failure on electrical contactor.
Damaged rectifier bridge.
Failure of the wire feed motor electrical supply.
Failure of wire feed motor brushes.
REPAIR
Check main supply voltage and protective
electrical circuits.
Check and replace, if necessary.
Check and replace, if necessary
Adjust the pressure system.
Clean properly and replace, if necessary.
Replace rolls with the adequate diameter.
Adjust with the adequate pressure
Check and replace, if necessary.
Check the bottle pressure and control de gas
flow.
Check and, if necessary, disassemble for
cleaning.
Protect the welding zone from wind or adjust up
the gas flow.
Clean or replace the torch nozzle.
Clean the welding surfaces.
Well tighten the earth clamp and torch. Check
the earth cable.
Disassemble and clean electrical contactor. If
not possible, replace contactor.
Check bridge and replace, if necessary.
Check and replace, if necessary the wire feed
motor fuse. Check the electrical insulating of the
wire feed motor.
Replace brushes.
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