Welding Circuit - ESAB LHI 425 Manual De Instrucciones

6.4)Welding circuit

The good functioning of a LHI 425 Pipeweld also depends on the use of an insulated copper welding cable,
which must be the shortest possible and compatible to the considered application(s), it must also be in good
shape and firmly connected to its terminals; Electrical connections in the to-be-welded piece or in the work
station and in the set "negative" terminal must be firm.
Whatever the length (the shortest possible) and whatever the used welding current, the welding cable must
correspond to the maximum current which the used RECTIFIER can supply at power factor 60%.
Welding circuit electrical strength causes voltage drops which add to Rectifier natural internal drop,
reducing the arc voltage and the maximum available current making the arc unstable.
7) OPERATION
After connecting the LHI 425 Pipeweld to the power supply system and connecting the electrode holder
cable and the work clamp, proceed to the following operations:
1) Place the ON/OFF switch on the ON position;
2) Preset the welding current through the panel or remote control potentiometer. The potentiometer
clockwise rotation increases the current value; anti clockwise rotation decreases current value;
3) Preset the Arc Force values;
4) Open the arc and, if necessary, readjust current or Arc Force, or both.
NOTE: the welding parameters value basically depend on the material and
electrode diameter in use, on the thickness of the to-be-welded piece as well
as on the welding position.
8) MAINTENANCE
8.1) General
In normal environment and operation conditions, LHI 425 Pipeweld does not require any special
maintenance service.You must only clean it internally at least once a month, with low pressure, dry and oil-
free compressed air.
After cleaning with compressed air, check the tightening of electrical and components connections. Check
for possible cracks in the insulation of electrical wires or cables, including welding cable and other
insulators. Replace them in case they are defective.
8.2) Repairing
To assure perfect functioning and performance of the ESAB equipment, use only original replacement parts
supplied by ESAB or the ones with its approval. The use of non-original or not-approved parts leads to
warranty cancellation.
Replacement parts can be purchased at ESAB authorised services or sales branches as indicated at the
last page of this manual.You must always indicate model and series number.
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LHI 425 Pipeweld