Alfa IN PEGAS 40 PLASMA PFC, Operating Manual, Page: 6 / 18

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ALFA IN a.s © www.alfain.eu 3
is the open-circuit voltage between the clamps. In our generator this
voltage is 380V.
•
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.
•
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
•
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
•
Before opening the machine switch off the machine and disconnect it from
the power socket.
•
Only personnel authorised by this company can carry out maintenance on
the machine.
2.1 ELECTROMAGNETIC COMPATIBILITY (EMC)
•
This machine conforms to EN 60974-10 standard. However, the
electromagnetic emissions generated could prove not be compatible with
the maximum permitted levels for some classes of electrical equipment,
such as the following:
•
Domestic electronic appliances (radios, TVs, videos, telephones,
burglar alarms, etc.).
•
Computers, robots, electro-medical instruments and life-support
systems.
•
Radio-television transmitters and receivers.
•
Pacemakers and hearing aids.