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■ Precautions on Welding
Check the following precautions when welding.
• Welding must be done on the concrete floor as long as possible. Do not weld on a wet
earth floor or metallic floor to avoid electric shock. Also avoid welding where there
are inflammables or exposure to wind.
• When moving the welder, do not exert excessive shock by throwing or dropping.
• The welder is the high DC voltage start type. This method applies high DC voltage
between the electrode and the base metal to start. If insulation cannot be assured
between the torch and the base metal grounding, high voltage is not applied resulting in
reduction of the arc start performance.
Refer to “■Precautions on Wiring of High DC Voltage Start Method” of “4.4
Connections of Elecric Systems.”
• To improve current conduction for welding, do not fail to tighten all the connections of
the cables and the other devices.
Imperfect contact or tightening of the connections may cause the cable to burn or the
unnecessary consumption power. Be sure that equipment is grounded to prevent
electric shock.
The following shows the allowable operational ratio when the welder is used at rated
current or less. It must not be used at current exceeding rated current.
Table 7.1 Relation between Operational Current
and Allowable Operational Ratio
Operational Ratio Operational
Current
40% 300 A
50% 270 A
60% 240 A
70% 225 A
80% 210 A
90% 195 A
100% 190 A
• The inverter welder is the forced air cooling type. Do not turn OFF the power supply
switch at least 5 or 6 minutes after completion of the operations.
• The cooling fan starts rotating as soon as the power supply is turned ON.
• The welder cannot be used for manual welding or gouging.
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