Safety and operating instructions
UM0933
6/16
Doc ID 17386 Rev 1
Electrical components must not be mechanically damaged or destroyed (in order to avoid
potential health risks).
2.2.1 Electronic
connection
National accident prevention rules must be followed when working on the main power
supply with the power supply or power board in general.
The electrical installation is completed in accordance with the appropriate requirements
(e.g., cross-sectional areas of conductors, fusing, or PE connections; for further information
see
2.2.2
2.5 kW/135 A welding machine demonstration setup
Special attention must be paid when setting a bench test to show the operation of the
2.5 kW/135 A welding machine.
This is a complete welding machine design, equipped with an analog welding logic control,
so also a real and practical welding process may be demonstrated.
●
Two options are available to startup the board.
–
working on a resistive dummy load
–
welding of real pieces of iron/steel
The first option (a resistive dummy load) is suggested if the user is not skilled in the welding
process. A suitable load is needed. Generally the plasma arc, responsible for metal arc
welding (in the case of iron or steel welding), can be modeled as follows (from the standard
regulation for MMA welding):
(representative of the peak voltage across the arc)
From this, assuming a welding current of 100 A is imposed, the output of the system is
about 24 V. The calculation of the equivalent resistive dummy load is:
Equation 1
A resistor, capable of dissipating the maximum power delivered by the machine (2.5 kW), in
a range of resistance between 0.2 and 0.3
Ω,
can be used. In this case a valid cooling
system (fan or water) should be used to diffuse the heat dissipated by the resistor.
For the second option, it is sufficient to connect a suitable clamp (available in most
specialized outlets, though not included in the demonstration package) to the negative
output of the board, through a cable not longer then 2 mt and with a cross section not less
than 16 mm
2
. Connect a suitable welding torch to the positive output, also using, in this
case, a cable with the same characteristics as for the negative connection. Once the clamp
is fixed to the iron sample, it is possible to start welding. A dedicated environment should be
considered for the demonstration. The demonstration must be carried out by persons skilled
in the arc welding process. The demonstration of a welding process can be dangerous to
the work environment or cause fire, due to the numerous incandescent sparks created by
the plasma arc. The work environment needs sufficient ventilation to assure the dispersion
of smoke caused by rod and metal fusion. Any person involved in the operation must wear
protective clothing, compliant with relevant accident prevention rules.
arc
arc
I
04
.
0
20
V
×
+
=
Ω
=
=
=
24
.
0
100
24
I
V
R
arc
arc
arc
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