Safety Requirements for Arc Welding and Cutting Equipments - Arc Welding Machines
Arc welding machines should be of suitable quality.
Construction of arc welding machines should be such that they can operate satisfactorily even under condition of :
(i) Saltish or moist air as in coastal areas,
(ii) Dust, smoke, fumes and gases,
(iii) Excessive shock or vibrations,
(iv) Steam and corrosive atmosphere, etc.
Arc welding machines should have open circuit or no-load voltage as low as possible consistent with good welding and the types of electrodes used and it should not exeed 100 volts for single operator DC welding and AC welding machines and 75 volts for constant voltage, multiple operator DC welding machines. All welding equipment shall be inspected periodically and maintained in safe working order at all times.
Welding equipment used in the open shall be protected from inclement weather conditions. Welding equipment if it has been wetted shall be thoroughly dried before being used. Arc welding machines should be properly ground (earthed).
Proper terminals should be used on the arc welding machines for the power line voltage connection. One should not work on the wiring of an arc welding machine unless qualified to do so.
In the case of DC arc welding motor generator machines
All parts of shall be suitably enclosed and protected meet the usual service conditions.
(ii) Neither terminal of the welding generator shall be bonded to the frame of the welding machine.
(iii) Periodically clear out the accumulated dust from the welding machine with a suction cleaner as this will not blow dust into other parts of the machine.
(iv) Lubricate regularly; but overgreasing may foul the commutator.
(v) Check and, if necessary, clean commutators periodically, using fine sand paper.
(vi) Excessive sparking may result in a worn commutator which may be cured by skimming in a lathe.
(vii) Brushes should move freely and have adequate spring tension.
This can be tested by lifting and releasing them. Brushes should snap back firmly against the commutator.
In the case of AC arc welding machines
(i) In transformers, the secondary circuit shall be thoroughly insulated from the primary.
(ii) Input terminals shall be completely enclosed and accessible only by means of tools.
(iii) The primary side of the transformer shall be provided with suitable wire terminals inside the machine case.
(iv ) Welding ( secondary) terminals shall be so arranged that current carrying parts are not exposed to accidental contact.
(v) In a transformer, the welding circuit should be quite separate from the power circuit, so that there is no risk of the welder suffering serious shock or burns through power voltage appearing across the electrode holder.
(vi) At or near each welding machine, a disconnecting switch shall be provided.
(vii) Control apparatus provided with the welding machine shall be enclosed except for the operating wheels, levers, etc.
(viii) Transformer windings be suction or compressed air cleaned periodically.
(ix) Greasing points need attention periodically.
(x) Switch contacts should be cleaned periodically.
(xi) Before undertaking any maintenance work on welding machines, disconnect them from the main supply.
As regards other arc welding equipment
(i) Electrode holders should be soundly connected to the welding lead. They should be of adequate rating for the maximum welding current to prevent them from heating up and becoming too hot to handle.
Electrode holders shall be provided with discs or shields to protect the hands of the welder from heat of the arc.
Insulation of all metallic or current carrying parts, including the jaws which grip the electrodes, is recommended.
Hot electrode holders shall not be permitted to dip in water because the retained moisture may cause an electric shock.
(ii) Welding cables shall be of completely insulated, flexible type. They should be capable of handling the maximum current requirements of the work in progress, taking into account the duty cycle under which the welder is working.
In case the cable insulation is damaged, do not operate the equipment. The welding cable should be free from repair or splices up to a minimum distance of 3 metres from the electrode holder. Fully insulated cable connectors of capacity at least equivalent to that of the cable shall be used to connect two cables together.
Welding cables shall be kept dry and free from grease and oil to avoid premature breakdown of the insulation.
(iii) The body or the frame of the welding machine shall be efficiently earthed.
Pipe lines containing gases or inflammable liquids or conduits carrying electrical conductors shall not be used for a ground return circuit. All earth connections shall be mechanically strong and electrically adequate for the required current.
Hope information helps. . .
Arc welding machines should be of suitable quality.
Construction of arc welding machines should be such that they can operate satisfactorily even under condition of :
(i) Saltish or moist air as in coastal areas,
(ii) Dust, smoke, fumes and gases,
(iii) Excessive shock or vibrations,
(iv) Steam and corrosive atmosphere, etc.
Arc welding machines should have open circuit or no-load voltage as low as possible consistent with good welding and the types of electrodes used and it should not exeed 100 volts for single operator DC welding and AC welding machines and 75 volts for constant voltage, multiple operator DC welding machines. All welding equipment shall be inspected periodically and maintained in safe working order at all times.
Welding equipment used in the open shall be protected from inclement weather conditions. Welding equipment if it has been wetted shall be thoroughly dried before being used. Arc welding machines should be properly ground (earthed).
Proper terminals should be used on the arc welding machines for the power line voltage connection. One should not work on the wiring of an arc welding machine unless qualified to do so.
In the case of DC arc welding motor generator machines
All parts of shall be suitably enclosed and protected meet the usual service conditions.
(ii) Neither terminal of the welding generator shall be bonded to the frame of the welding machine.
(iii) Periodically clear out the accumulated dust from the welding machine with a suction cleaner as this will not blow dust into other parts of the machine.
(iv) Lubricate regularly; but overgreasing may foul the commutator.
(v) Check and, if necessary, clean commutators periodically, using fine sand paper.
(vi) Excessive sparking may result in a worn commutator which may be cured by skimming in a lathe.
(vii) Brushes should move freely and have adequate spring tension.
This can be tested by lifting and releasing them. Brushes should snap back firmly against the commutator.
In the case of AC arc welding machines
(i) In transformers, the secondary circuit shall be thoroughly insulated from the primary.
(ii) Input terminals shall be completely enclosed and accessible only by means of tools.
(iii) The primary side of the transformer shall be provided with suitable wire terminals inside the machine case.
(iv ) Welding ( secondary) terminals shall be so arranged that current carrying parts are not exposed to accidental contact.
(v) In a transformer, the welding circuit should be quite separate from the power circuit, so that there is no risk of the welder suffering serious shock or burns through power voltage appearing across the electrode holder.
(vi) At or near each welding machine, a disconnecting switch shall be provided.
(vii) Control apparatus provided with the welding machine shall be enclosed except for the operating wheels, levers, etc.
(viii) Transformer windings be suction or compressed air cleaned periodically.
(ix) Greasing points need attention periodically.
(x) Switch contacts should be cleaned periodically.
(xi) Before undertaking any maintenance work on welding machines, disconnect them from the main supply.
As regards other arc welding equipment
(i) Electrode holders should be soundly connected to the welding lead. They should be of adequate rating for the maximum welding current to prevent them from heating up and becoming too hot to handle.
Electrode holders shall be provided with discs or shields to protect the hands of the welder from heat of the arc.
Insulation of all metallic or current carrying parts, including the jaws which grip the electrodes, is recommended.
Hot electrode holders shall not be permitted to dip in water because the retained moisture may cause an electric shock.
(ii) Welding cables shall be of completely insulated, flexible type. They should be capable of handling the maximum current requirements of the work in progress, taking into account the duty cycle under which the welder is working.
In case the cable insulation is damaged, do not operate the equipment. The welding cable should be free from repair or splices up to a minimum distance of 3 metres from the electrode holder. Fully insulated cable connectors of capacity at least equivalent to that of the cable shall be used to connect two cables together.
Welding cables shall be kept dry and free from grease and oil to avoid premature breakdown of the insulation.
(iii) The body or the frame of the welding machine shall be efficiently earthed.
Pipe lines containing gases or inflammable liquids or conduits carrying electrical conductors shall not be used for a ground return circuit. All earth connections shall be mechanically strong and electrically adequate for the required current.
Hope information helps. . .