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Linde AG, Linde Gas Deutschland ©
26. The operator must NEVER weld containers that have previously
contained petrol, lubricants, gas or similar flammable materials, even if
the container has been empty for a considerable time. THERE IS A VERY
HIGH RISK OF EXPLOSION.
27. The operator must be aware of all the special regulations which he
needs to conform to when cutting in enclosed spaces with a high risk of
explosion.
28. To prevent electric shock, we strongly suggest the following rules:
29. Do not work in a damp or humid environment.
30. Do not use the machine if its cables are damaged in any way.
31. Make sure that the earthing system of the electric equipment is
correctly connected and operational.
32. The operator must be insulated from the metal components connected
to the return wire.
33. The earthing of the piece being worked could increase the risk of injury
to the operator.
34. EN 60974-1 Standard: Open-circuit voltage. During the operation of
the machine, the highest voltage, with which it is possible to come into
contact, is the open-circuit voltage between the clamps.
35. The maximum open-circuit voltage of the plasma machines is
established by national and international standards (EN 60974-1)
depending on the type of current to be used, on its waveform and on the
hazards arising from the work place. These values are not applicable to
the strike currents and those for stabilisation of the arc that could be
above it.
36. The open-circuit voltage, for as many adjustments as possible, must
never exceed the values relating to the various cases shown in the
following table:
Case Working conditions
Open-circuit voltage
1
Places with increased
risk of electric shock
DC current: 113V
peak value
AC current: 68V
peak value and 48V
effective
2
Places without increased
risk of electric shock
DC current: 113V
peak value
AC current: 113V
peak value and 80V
effective
3
Torches held
mechanically with
increased protection for
the operator
DC current: 141V
peak value
AC current: 141V
peak value and
100V effective
4
Plasma cutting
DC current: 500V
peak value
37. In case 1, the dc machines with rectifier must be built in such a way
that, in case of a fault developing in the rectifier (for example open circuit,
