Power Supply; Operating Environment - Weldclass FORCE 200MST MK2 Operating Instructions Manual

MIG Voltage & MIG Wire Speed / MMA
& Lift TIG Current Control Knobs
MIG Welding Mode
The MIG voltage control is essentially the power in
the welding arc that sets the heat. The wire speed
feed simply controls the rate at which the welding
wire is fed into the weld pool.
For any voltage position setting, there will be a
specific corresponding 'sweet spot' in the wire
feeding speed that will give the smoothest and
most stable welding arc. The correct wire feeding
speed for a given voltage setting is affected by
welding wire type and size, shielding gas, welding
material and joint type.
It is recommended to set the welding voltage as
desired and then slowly adjust the wire speed until
the arc is smooth and stable. When reaching this
point, if the penetration/ heat input is too much/
not enough, adjust the voltage setting and repeat
the process. If the operator is not able to achieve a
smooth and stable arc with the desired heat input
for the weld, it is likely that a change in wire size
and/or shielding gas type is required (assuming all
other factors are correct).
A chart with recommended settings using this
machine for common welding applications is
located on the underside 0f the wire feeder cover
door and further on in this manual.
MMA/ Lift TIG Welding Mode
The current control knob sets the target welding
output current for either mode selected. The
voltage knob has no effect in MMA or TIG mode.
MIG Inductance Control - Inductance adjustment
controls the rate of the current rise and fall as
the welding wire contacts the workpiece (known
as a short circuit). More inductance increases the
short circuit time and decreases the short circuit
frequency rate. This causes a wider and more
penetrating arc, useful for thicker weld joints. Less
inductance will create a narrow more focused arc.
This effect can also be used to fine tune the arc to
produce less splatter. Wire speed, wire size and
type, shielding gas will all change the effect that
the inductance setting has on the welding arc. As
a general rule, CO2 based shielding gas will weld
more smoothly with increased inductance, while
argon shielding gas will perform better with less
inductance. Inductance setting will have no effect
on MIG spray transfer process (as opposed to short
circuit process), MMA or TIG welding process.
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Lift TIG Mode
Lift TIG is an arc ignition system for basic TIG welding
that removes the need to 'scratch' start or strike the
tungsten on the work piece to start the arc, which
can have a negative effect on the weld quality due
to tungsten contamination. Lift arc starting works
by gently touching the tungsten on the work piece
and then lifting it off. The control circuit will sense
when the tungsten is removed from the work piece
and send a pulse of electricity through the torch
that will cause the TIG arc to initiate.
Overload Indicator Lamp
Lights when duty cycle is exceeded and thermal
protection is activated. When thermal protection
is activated, welding output will be disabled until
machines cools sufficiently and overload indicator
lamp goes out. Also may activate with inverter
circuit failure issues.

Power Supply

Electrical Connection
The Force 200MST is designed to operate on a 15A
240V AC power supply.
Extension Leads
If an extension cord must be used, it should be
minimum cable core size 2.5mm
leads of over 20m is not recommended.
Generator Use
This machine has a wide input power variation
tolerance (~170-265V), allowing it to operate off
generator power.
Generator size should be not less than 8kva. Avoid
using poor, low quality generators as these have
the greatest risk of power spikes etc. A suitable
quality generator should have a THD (total harmonic
distortion) rating of not more than 6%. Most
reputable generator supplier will be able to specify
the THD ratings on their product.

Operating Environment

Adequate ventilation is required to provide proper
cooling for the 200MST. Ensure that the machine is
placed on a stable level surface where clean cool air
can easily flow through the unit. The 200MST has
electrical components and control circuit boards
which may be damaged by excessive dust and dirt,
so a clean operating environment is essential.
. Using extension
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