SanRex SANMIG 200MF User manual

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8.850.142
2018.9.20
SANMIG 200MF
INVERTER DC MIG WELDER
IMPORTANT: Read this Owner’s Manual Completely before attempting to use this
equipment. Save this manual and keep it handy for quick reference. Pay particular
attention to the safety instructions we have provided for your protection. Contact your
distributor if you do not fully understand this manual.
OPERATOR’S MANUAL

II
CONTENT
§1 SAFETY --------------------------------------------------------------------------------------------------------- 1
§1.1 SIGNAL EXPLANATION -----------------------------------------------------------------------------------------1
§1.2ARC WELDING DAMAGE---------------------------------------------------------------------------------------1
§1.3 THE KNOWLEDGE OF ELECTRIC AND MAGNETIC FIELDS -------------------------------------------------5
§2 SUMMARY ----------------------------------------------------------------------------------------------------- 6
§2.1 BRIEF INTRODUCTION -----------------------------------------------------------------------------------------6
§2.2 MODULE EXPLANATION ---------------------------------------------------------------------------------------7
§2.3 WORKING PRINCIPLE-------------------------------------------------------------------------------------------7
§2.4 VOLT-AMPERE CHARACTERISTIC ----------------------------------------------------------------------------8
§3 INSTALLATION AND ADJUSTMENT------------------------------------------------------------------- 9
§3.1 PARAMETERS ----------------------------------------------------------------------------------------------------9
§3.2 DUTY CYCLE &OVER HEAT--------------------------------------------------------------------------------- 13
§3.3 MOVEMENTAND PLACEMENT ------------------------------------------------------------------------------ 14
§3.4 POWER SUPPLY INPUT CONNECTION------------------------------------------------------------------------ 15
§3.5 POLARITY CONNECTION（MMA）----------------------------------------------------------------------- 15
§3.6ASSEMBLING THE EQUIPMENT (TIG) ---------------------------------------------------------------------- 16
§4 OPERATION --------------------------------------------------------------------------------------------------18
§4.1 LAYOUT FOR THE PANEL ------------------------------------------------------------------------------------- 18
§4.2 CONTROL PANEL ---------------------------------------------------------------------------------------------- 21
§4.3ARGON ARC WELDING OPERATION ------------------------------------------------------------------------ 25
§4.3.1 TIG welding （ 4T operation ） -----------------------------------------------------------------25
§4.3.2 TIG welding (2T operation) ------------------------------------------------------------------------26
§4.4 WELDING PARAMETERS ------------------------------------------------------------------------------------- 27
§4.4.1 Joint forms in TIG/MMA----------------------------------------------------------------------------27
§4.4.2 The explanation of welding quality----------------------------------------------------------------28
§4.4.3 TIG Parameters Matching--------------------------------------------------------------------------28
§4.5 OPERATION ENVIRONMENT --------------------------------------------------------------------------------- 30
§4.6 OPERATION NOTICES----------------------------------------------------------------------------------------- 30
§5 MAINTENANCE & TROUBLESHOOTING-----------------------------------------------------------31
§5.1 MAINTENANCE------------------------------------------------------------------------------------------------ 31
§5.2 TROUBLESHOOTING ------------------------------------------------------------------------------------------ 32
§5.3 ELECTRICAL PRINCIPLE DRAWING-------------------------------------------------------------------------- 35

SAFETY
1
§1 SAFETY
§1.1 Signal Explanation
The above signals mean warning! Notice! Running parts and getting an electric shock or thermal parts
will take damage for your body or others. The corresponding notices are as follows. It is quite a safe
operation after taking several necessary protection measures.
§1.2 Arc Welding Damage
The following signals and word explanations are to some damages for your body or others happening
on the welding operation. While seeing these, please remind of yourself or others to be dangerous.
Only ones who are trained professionally can install, debug, operate, maintain and repair the
equipment.
During the operation, non-concerned people should be lift, especially for children.
After shut off the machine power, please maintain and examine the equipment according to §5
because of the DC voltage existing in the electrolytic capacitors.
ELECTRIC SHOCK CAN KILL.
Never touch electrical parts.
Wear dry, hole-free gloves and clothes to insulate yourself.
Insulate yourself from work and ground using dry insulation. Make certain the insulation is large
enough to cover your full area of physical contact with work and ground.
Take carefully when using the equipment in small place, falling-off and wet circumstance.
Never close the machine power before installation and adjustment.
Ensure to install the equipment correctly and ground the work or metal to be welded to a good
electrical (earth) ground according to the operation manual.
The electrode and work (or ground) circuits are electrically “hot” when the welder is on. Do not touch
these “hot” parts with your bare skin or wet clothing. Wear dry, hole-free gloves to insulate hands.
In semiautomatic or automatic wire welding, the electrode, electrode reel, welding head, nozzle or

SAFETY
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semiautomatic welding gun are also electrically “hot”.
Always be sure the work cable makes a good electrical connection with the metal being welded. The
connection should be as close as possible to the area being welded.
Maintain the electrode holder, work clamp, welding cable and welding machine in good, safe
operating condition. Replace damaged insulation.
Never dip the electrode in water for cooling.
Never simultaneously touch electrically “hot” parts of electrode holders connected to two welders
because voltage between the two can be the total of the open circuit voltage of both welders.
When working above floor level, use a safety belt to protect yourself from a fall should you get a
shock.
FUMESAND GASES CAN BE DANGEROUS.
Welding may produce fumes and gases hazardous to health. Avoid breathing these fumes and gases.
When welding, keep your head out of the fume. Use enough ventilation and/or exhaust at the arc to keep
fumes and gases away from the breathing zone. When welding with electrodes which require special
ventilation such as stainless or hard facing or on lead or cadmium plated steel and other metals or
coatings which produce highly toxic fumes, keep exposure as low as possible and below Threshold
Limit Values using local exhaust or mechanical ventilation. In confined spaces or in some circumstances,
outdoors, a respirator may be required. Additional precautions are also required when welding on
galvanized steel.
Do not weld in locations near chlorinated hydrocarbon vapors coming from degreasing, cleaning or
spraying operations. The heat and rays of the arc can react with solvent vapors to form phosgene, a
highly toxic gas, and other irritating products.
Shielding gases used for arc welding can displace air and cause injury or death. Always use enough
ventilation, especially in confined areas, to insure breathing air is safe.
Read and understand the manufacturer’s instructions for this equipment and the consumables to be
used, including the material safety data sheet and follow your employer’s safety practices.
ARC RAYS CAN BURN.
Use a shield with the proper filter and cover plates to protect your eyes from sparks and the rays of the

SAFETY
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arc when welding or observing open arc welding.
Use suitable clothing made from durable flame-resistant material to protect your skin and that of your
helpers from the arc rays.
Protect other nearby personnel with suitable, non-flammable screening and /or warn them not to
watch the arc nor expose themselves to the arc rays or to hot spatter or metal.
SELF-PROTECTION
Keep all equipment safety guards, covers and devices in position and in good repair. Keep hands, hair,
clothing and tools away from V-belts, gears, fans and all other moving parts when starting, operating or
repairing equipment.
Do not put your hands near the engine fan. Do not attempt to override the governor or idler by
pushing on the throttle control rods while the engine is running.
DO NOT adds the fuel near an open flame welding arc or when the engine is
running. Stop the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on
contact with hot engine parts and igniting. Do not spill fuel when filling tank. If fuel is spilled, wipe it
up and do not start engine until fumes have been eliminated.
WELDING SPARKS can cause fire or explosion.
Remove fire hazards from the welding area. If this is not possible, cover them to prevent the welding
sparks from starting a fire. Remember that welding sparks and hot materials from welding can easily go
through small cracks and openings to adjacent areas. Avoid welding near hydraulic lines. Have a fire
extinguisher readily available.
Where compressed gases are to be used at the job site, special precautions should be used to prevent
hazardous situation.
When not welding, make certain no part of the electrode circuit is touching the work or ground.
Accidental contact can cause overheating and create a fire hazard.
Do not heat, cut or weld tanks, drums or containers until the proper steps have been taken to insure
that such procedures will not cause flammable or toxic vapors from substances inside. They can cause

SAFETY
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an explosion even though they have been “cleaned”.
Vent hollow castings or containers before heating, cutting or welding. They may explode.
Sparks and spatter are thrown from the welding arc. Wear oil free protective garments such as leather
gloves, heavy shirt, cuff less trousers, high shoes and a cap over your hair. Wear ear plugs when welding
out of position or in confined places. Always wear safety glasses with side shields when in a welding
area.
Connect the work cable to the work as close to the welding area as practical. Work cables connected
to the building framework or other locations away from the welding area increase the possibility of the
welding current passing through lifting chains, crane cables or other alternate circuits. This can create
fire hazards or overheat lifting chains or cables until they fail.
Rotating parts may be dangerous.
Use only compressed gas cylinders containing the correct shielding gas for the process used and
properly operating regulators designed for the gas and pressure used. All hoses, fittings, etc. should be
suitable for the application and maintained in good condition.
Always keep cylinders in an upright position securely chained to an undercarriage or fixed support.
Cylinders should be located:
-Away from areas where they may be struck or subjected to physical damage.
-A safe distance from arc welding or cutting operations and any other source of heat, sparks, or
flame.
Never allow the electrode, electrode holder or any other electrically “hot” parts to touch a cylinder.
Keep your head and face away from the cylinder valve outlet when opening the cylinder valve.
Valve protection caps should always be in place and hand tight except when the cylinder is in use or
connected for use.

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§1.3 The knowledge of Electric and Magnetic Fields
Electric current flowing through any conductor causes localized Electric and Magnetic Fields
(EMF). The discuss on the effect of EMF is ongoing all the world. Up to now, no material evidences
show that EMF may have effects on health. However, the research on damage of EMF is still ongoing.
Before any conclusion, we should minimize exposure to EMF as few as possible.
In order to minimize EMF, we should use the following procedures:
Route the electrode and work cables together –Secure them with tape when possible.
All cables should be put away and far from the operator.
Never coil the power cable around your body.
Make sure welding machine and power cable to be far away from the operator as far as possible
according to the actual circumstance.
Connect the work cable to the workpiece as close as possible to the area being welded.
The people with heart-pacemaker should be away from the welding area.

SUMMARY
6
§2 SUMMARY
§ 2.1 Brief Introduction
SANMIG 200MF welding machine 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 work frequency transformer with the cabinet
medium frequency transformer. Thus, it is characterized with portable, small size, light weight, low
consumption and etc.
The machine adopts ZVS and PFC full bridge inverter technology. Single phase alternating
current(AC) after full bridge rectifier ,after PFC for power factor correction，adopting the boost booster
technology ,and then through filter, the whole bridge rectifier．In order to improve the efficiency of the
power supply，this machine is using ZVS technology and the phase-shifting control the average
current control mode, makes the efficiency and power factor of the power supply had a remarkable
improvement. At the same time, this machine can realize three welding patterns, such as MMA,MIG,
TIG, so it can satisfy all kinds of welding.
SANMIG 200MF Characteristics：
★The ZVS soft switch technology reduces the IGBT switching loss.
★The machine uses the PFC technology, so it can use in the situations of
110V/220V, and the power factor of the welder has a remarkable
improvement, close to 1.
★The efficiency of the machine has a lot of improvement, in the state of
MMA, it can reach nearly 84%;
★The machine uses the average current control mode, and have general
protection functions, for example the limited overshoot, the limit of
the pulse width, overvoltage, over-current, over-heating and so on.

SUMMARY
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Those functions obviously improve the stability and security of the
welding machine.
★The panel combines two kinds of control modes, making it easy for
user to operate.
★MCU control system, responds immediately to any changes.
★Reduse the weight of the machine, improve the mobility of the
welder.
SANMIG 200MF is suitable for all positions welding for various plates made of stainless steel,
carbon steel, alloyed steel, titanium, magnesium, cuprum, etc, which is also applied to pipe installment,
mould mend, petrochemical, architecture decoration, car repair, bicycle, handicraft and common
manufacture.
MMA——Manual Metal Arc welding
PWM——Pulse-Width Modulation
IGBT——Insulation Gate Bipolar Transistor
TIG——Tungsten Insert Gas welding
§2.2 Module Explanation
SAN MIG 200MF
MIG
Max current 200A LCD
display
Soft-switching technology
§2.3 Working Principle
The working principle of SANMIG 200MF is shown as the following figure. Single phases
work frequency AC 220V (50 Hz) is rectified into DC (about 380V), then is converted to medium
frequency AC (about 44KHz) by inverter device (IGBT), after reducing voltage by medium transformer

SUMMARY
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(the main transformer) and rectifying by medium frequency rectifier (fast recovery diode), and is
outputted by inductance filtering. 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.
Rectify Inverter Medium
frequency
transformer
Medium
frequency
rectify Hall device
Current positive-
feedback control
DC AC DCAC DC
220V,50HZ
Single-phases AC
§2.4 Volt-Ampere Characteristic
SANMIG 200MF welding machine has an excellent volt-ampere characteristic, whose graph is
shown as the following figure. The relation between the conventional rated loading voltage U2and the
conventional welding current I2is as follows:
When I2≤600A，U2=10+0.04I2(V); When I2＞600A,U2=34(V).
67
34
10
0 600 I2（A）
U2（V）
Working
point
Volt-ampere characteristic The relation between the
conventional loading
voltage and welding current