Vector Welding C-Series Operating Instructions Manual page 47

MULTIFUNCTION SERIES EQUIPMENT
Summary
1.1 Brief Introduction
O241, O251 welding machines adopts the latest pulse width modulation (PWM)
technology and insulated gate bipolar transistor (IGBT) power module, which can
change work frequency to medium frequency so as to replace the traditional hulking
ork frequency transformer with the cabinet medium frequency transformer. Thus, its
characterized with portable, small size, light weight, low consumption and etc.
The parameters of on the front panel all can be adjusted continuously and steplessly,
such as start current, crater arc current, welding current, base current, duty ratio, upslope
time, downslope time, pre-gas, post-gas, pulse frequency, AC frequency, balance, hot start,
arc force and length etc. When welding, it takes high frequency and high voltage for arc
igniting to ensure the success ratio of igniting arc.
O241 O251 machines Characteristics::
◆MCU control system, responds immediately to any changes.
◆High frequency and high voltage for arc igniting to ensure the success ratio of
igniting arc, the reverse polarity ignition ensures good ignition behavior in TIG-AC
welding.
◆Avoid AC arc-break with special means, even if arc-break occurs the HF will keep
the arc stable.
◆Pedal control the welding current.
◆In DC TIG without HFopertation, If the tungsten electrode touches the workpiece
when welding, the current will drop to short-circuit current to protect tungsten.
Intelligent protection: over-current, over-heat, when the mentioned problems
◆
occoured, the alarm lamp on the front panel will be on and the output current will
be cut off. It can self-protect and prolong the using life.
◆D o u b l e p u r p o s e s : A C i n v e r t e r T I G a n d D C i n v e r t e r T I G / M M A , E x c e l l e n t
performance on AL-alloy, carbon steel, stainless steel, titanium.
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MULTIFUNCTION SERIES EQUIPMENT
1.2 Working Principle
The working principle of O241/O251 welding machines is shown as the following figure.
Single-phase 230V work frequency AC is rectified into DC (about 312 V), then is converted
to medium frequency AC (about 20-40KHz) by inverter device (IGBT module), after
reducing voltage by medium transformer (the main transformer) and rectifying by medium
frequency rectifier (fast recovery diodes), then is outputted DC or AC by selecting IGBT
module. The circuit adopts current feedback control technology to insure current output
stably. Meanwhile, the welding current parameter can be adjusted continuously and
steplessly to meet with the requirements of welding craft.
230V,50Hz
1.3 Volt- Ampere Characteristic
O 2 4 1 / O 2 5 1 w e l d i n g
machine has an excellent
volt-ampere characteristic,
whose graph is shown as
the following figure. The
r e l a t i o n b e t w e e n t h e
conventional rated loading
voltage U and the conve
2
-ntional welding current
I is as follows:
2
TIG
When I ≤600A, U =10+0.04I (V);
2 2 2
When I >600A,U =34(V).
2 2
MMA
When I ≤600A, U =20+0.04I (V);
2 2 2
When I >600A,U =44(V).
2 2
CUT
When I ≤600A, U =80+0.4I (V);
2 2 2
Summary
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