11
General overview: The Mul-Process PowerPro 256Si
oers an improved design with a new modular structure.
This new design includes digital control and a more ro-
bust internal design to improve reliability and perfor-
mance while simplifying circuitry and reducing weight.
The key features of the PowerPro 256Si include:
A. Digital control and componenzed unit design reduc-
es complexity of circuitry and components, reducing
the overall number of components. This is aimed at
improving lifespan and long term serviceability of
the Mul-Process TIG/Sck Plasma plaorm.
B. Digital control oers more precise control over pa-
rameters, and oers a more sasfactory operang
experience by minimizing service and operaonal
issues found in the typical TIG/Sck/Plasma mul-
process welder/cuer unit.
C. Full-wave bridge recer inverter design also fea-
tures so switching technology which further ex-
tends IGBT component life.
D. HF point gap adjustment issues have been reduced
with the introducon of new HF board design.
E. Digital components oer reduced weight and im-
proved operang eciency over past analog con-
trolled generaons.
F. The digitally controlled square wave design creates a
stable arc in AC, with a fast melng puddle and
good wet-in.
G. Adjustable arc force control and adapve hot start
helps improve the SMAW process performance.
H. Plasma operaon has been improved with a new
generaon of torches featuring the iPT 60 torch.
General Use and Care: With proper care, the PowerPro’s
digitally controlled inverter components are designed to
withstand years of use in many dierent welding envi-
ronments. However, remember to keep the unit out of
direct contact with water spray and corrosive areas. The
unit has an ingress rang of IP21S, for light dripping wa-
ter (condensaon). It is a good idea to remove the weld-
er from the vicinity of any water or moisture source to
reduce the possibility of electrocuon or shock. Never
operate in standing water or where water spray is an
issue. Every 1-2 months, depending upon use, the weld-
er should be unplugged, opened up and carefully cleaned
with compressed air. Regular maintenance will extend
the life of the unit. Metallic dust build up may lead to
premature board and component failure.
CAUTION: Before opening the unit for any reason,
make sure the unit has been unplugged for at least 10
minutes to allow me for the capacitors to fully dis-
charge. Severe shock and/or death can occur.
Free, unobstructed air ow is crical to cooling and duty
cycle. Do not restrict air ow or movement of air around
the welder. Allow a buer distance of 2 from all sides,
with a minimum distance of 18” clearance. Do not oper-
ate the welder in the immediate vicinity of the weld area
or the discharge of air from the fan will cause turbulence
and will destabilize the arc and cause weld porosity. Do
not mount in areas that are prone to severe shock or vi-
braon. Do not drop the unit. Li and carry the welder by
the handle. Strap the welder down for maximum stability
during use. Do not direct metallic dust or any dirt toward
the machine, parcularly in grinding and welding opera-
ons. Flip down the clear front cover aer compleng
adjustment to protect the control panel.
Duty Cycle. For the PowerPro 256Si, the TIG duty cycle is
rated for 60% at 250 amps. The duty cycle is based o a
10 minute duty cycle rang at 40°C and 35% for Sck/
Plasma at 200/60 Amps, respecvely. This means that the
unit is capable of being operated at the stated amps for 6
out of every 10 minutes without a break in welding to cool
down the unit. (3.5 out of 10 minutes for sck/plasma
operaon.) For TIG a full 4 minute (6.5 minute for sck/
plasma) rest should be given if operang at or near maxi-
mum capacity of the welder for maximum life. The tem-
perature light will come on and the welder will automa-
cally stop welding when an overheat condion has oc-
curred. The fan and display will connue to be operate.
Do not turn the unit o or aempt to reset the unit for at
least 15 minutes aer an overheat condion has occurred
as heat will connue to be generated by and transferred
to the electronics aer welding has ceased. Welding in
humid or hot condions greater than 40°C can negavely
aect duty cycle. Once the overheated condion has
cleared, welding can resume. Do not operate the welder
with the covers removed. The welder duty cycle interrupt
is controlled by temperature sensors and not me sen-
sors, so the duty cycle limiter funcon will dier some-
what from the actual me used based o the operang
condions in the welding environment.
IMPORTANT!
Operang the PowerPro unit in such a way that causes
the unit to repeatedly surpass the duty cycle limit will
signicantly decrease the life-span of the electronics or
cause permanent damage to the welder. However, an
occasional duty cycle interrupt event should not be an
issue if the prescribed cool-down procedures are fol-
lowed. If you nd that the unit is being repeatedly oper-
ated up to and beyond the duty cycle limit of the ma-
chine, it is likely that a larger welder/cuer is needed for
the job. Or, consider separate units with higher duty cy-
cles for dedicated service. Keep in mind many things can
Introduction and Specifications
Section 1