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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.
31. 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
32. 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, short
circuit or lack of power), the permitted values cannot be exceeded. The
plasma cutting machines of this type can be marked with the symbol:
S
33. Before opening the machine switch off the machine and disconnect it from
the power socket.
34. Only personnel authorised by this company can carry out maintenance on
the machine.
PROTECTIVE UTTILITIES
1. Welding helmet with filter shade at least 10
2. Welding gloves
3. Welding apron and cloth
4. Welding boots
RISK OVERVIEW
1. Risk of electric shock
2. Ultraviolet light and light radiation
3. Risk of inhaling gas fumes and dust particles
4. Burns
5. Noise
