Rtech Tig200 DC Digital User manual

Tig200 DC Digital
Tig Welder
Operating Instructions
www.r-techwelding.co.uk
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Important Notice: This document has been prepared by R-Tech Welding Ltd.
as general information and does not contain and is not to be taken as containing any specific
recommendation.The document has been prepared in good faith and is professional opinion only. Information in this
document has been derived from third parties, and though R-Tech Welding Ltd believes it to be reliable as at the time of printing,
R-Tech Welding makes no representation or warranty as to the accuracy, reliability or completeness of information in this
document and does not assume any responsibility for updating any information or correcting any error or omission which
may become apparent after the document has been issued. Neither R-Tech Welding nor any of its agents has independently
verified the accuracy of the information contained in this document.The information in this document is commercial in
confidence and is not to be reproduced.The recipient acknowledges and agrees that it must make its own independent
investigation and should consider seeking appropriate professional recommendation in reviewing and evaluating the
information.This document does not take into account the particular circumstances of the recipient and the recipient
should not rely on this document in making any decisions, including but not limited to business, safety or other operations
decisions. Except in so far as liability under any statute cannot be excluded, R-Tech Welding and its affiliates, directors, employees,
contractors and consultants do not accept any liability (whether arising in contract, tort or otherwise) for any error or
omission in this document or for any resulting loss or damage (whether direct, indirect, consequential or otherwise) suffered
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document or any other information.

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Contents
1.0 Recommended Safety Precautions
1.1 Health Hazard Information 6
1.2 Personal Protection 6
1.3 Electric Shock 8
1.4 User Responsibility 8
2.0 Gas Tungsten Arc Welding (GTAW/TIG)
2.1 Introduction 9
2.2 Process 9
2.3 Process Variables 9
2.4 Shielding Gas Selection 11
2.5 Consumable Selection 12
2.6 Welding Techniques 13
2.7 Torch Movement During Welding 8
2.8 Joint Preparation 17
3.0 TIG Welding of Materials
3.1 Application Summary 21
3.2 C-Mn Steel 22
3.3 Alloyed Steel 23
3.4 Stainless Steel 24
3.5 Aluminium 25
3.6 Balanced Squarewave 25
3.7 Copper and Copper Alloys 26
4.0 Connection Your R-Tech
TIG200DC PFC
4.1 Power 28
4.2 Shielding Gas 28
4.3 TIG Torch Connection 28
4.4 MMA Operation 28
4.5 TIG Welding Operation 29
5.0 Technical Specifications 32
6.0 Warranty
6.1 Terms of Warranty 33
6.2 Limitations on Warranty 33
6.3 Warranty Repairs 33

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1.1 Health Hazard Information
The actual process of welding is one that can
cause a variety of hazards.All appropriate
safety equipment should be worn at all times,
i.e. headwear, respiratory, hand and body
protection. Electrical equipment should be
used in accordance with the manufactur ser
recommendations.
Eyes:
The process produces ultra violet rays that
can injure and cause permanent damage.
Fumes can cause irritation.
Skin:
Arc rays are dangerous to uncovered skin.
Inhalation:
Welding fumes and gases are dangerous to
the health of the operator and to those in
close proximity.The aggravation of pre-existing
respiratory or allergic conditions may occur in
some workers. Excessive exposure may cause
conditions such as nausea, dizziness, dryness
and irritation of eyes, nose and throat.
1.2 Personal Protection
Respiratory
Confined space welding should be carried out
with the aid of a fume respirator or air supplied
respirator as per AS/NZS 1715 and AS/NZS
1716 Standards.
You must always have enough ventilation in
confined spaces. Be alert to this at all times.
Keep your head out of the fumes rising from
the arc.
Fumes from the welding of some metals could
have an adverse effect on your health. ’tDon
breathe them in. If you are welding on material
such as stainless steel, nickel, nickel alloys
or galvanised steel, further precautions are
necessary.
Wear a respirator when natural or forced
ventilation is not good enough.
Eye protection
A welding helmet with the appropriate welding
filter lens for the operation must be worn at all
times in the work environment.The welding arc
and the reflecting arc flash gives out ultraviolet
and infrared rays. Protective welding screen and
goggles should be provided for others working
in the same area.
Clothing
Suitable clothing must be worn to prevent
excessive exposure to UV radiation and
sparks.An adjustable helmet, flameproof loose
fitting cotton clothing buttoned to the neck,
protective leather gloves, spats, apron and steel
capped safety boots are highly recommended.
Recommended filter shades for
arc welding
Less than 150 amps Shade 10*
150 to 250 amps Shade 11*
250 to 300 amps Shade 12
300 to 350 amps Shade 13
Over 350 amps Shade 14
*Use one shade darker for aluminium
1.0 Recommended Safety Precautions

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Cylinder Safety
Ten Points about Cylinder Safety
1 Read labels and Material Safety Data Sheet
(MSDS) before use.
2 Store upright and use in well ventilated,
secure areas away from pedestrian or vehicle
thoroughfare.
3 Guard cylinders against being knocked
violently or being allowed to fall.
4Wear safety shoes, glasses and gloves when
handling and connecting cylinders.
5 Always move cylinders securely with an
appropriate trolley.Take care not to turn the
valve on when moving a cylinder.
6 Keep in a cool, well ventilated area, away
from heat sources, sources of ignition and
combustible materials, especially flammable
gases.
7 Keep full and empty cylinders separate.
8 Keep ammonia-based leak detection
solutions, oil and grease away from cylinders
and valves.
9 Never use force when opening or closing
valves.
10 Don’t repaint or disguise markings and
damage. If damaged, return cylinders to
your local supplier.
Cylinder Valve Safety
When working with cylinders or operating
cylinder valves, ensure that you wear
appropriate protectiv ves, bootse clothing glo
and safety glasses.
When moving cylinders, ensure that the valve is
not accidentally opened in transit.
Before operating a cylinder valve:
Ensure that the system you are connecting the
cylinder into is suitable for the gas and
pressure involved.
Ensure that any accessories (such as hoses
attached to the cylinder valve, or the system
being connected to) are securely connected.
A hose, for example, can potentially flail
around dangerously if it is accidentally
pressurised when not restrained at both ends.
Stand to the side of the cylinder so that
neither you nor anyone else is in line with
the back of the cylinder valve.This is in case a
back-plus is loose or a bursting disc vents.The
correct stance is shown in the diagram above.
When operating the cylinder valve:
Open it by hand by turning the valve hand-
wheel anti-clockwise. Use only reasonable force.
Ensure that no gas is leaking from the cylinder
valve connection or the system to which the
cylinder is connected. DO NOT use
ammonia-based leak detection fluid as this can

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damage the valve.Approved leak detection
fluid can be obtained from a gas supplier
When finished with the cylinder, close the
cylinder valve by hand by turning the valve
hand-wheel in a clockwise direction. Use only
reasonable force.
1.3 Electrical Shock
Never touch live electrical parts.
Always repair or replace worn or
damaged parts.
Disconnect power source before
performing any maintenance or service.
Earth all work materials.
Never work in moist or damp areas.
Avoid electric shock by:
Wearing dry insulated boots
Wearing dry leather gloves
Never changing electrodes with bare
hands or wet gloves
Never cooling electrode holders in water
Working on a dry insulated floor where
possible
Never hold the electrode and holder
under your arm.
1.4 User Responsibility
Read the Operating Manual prior to
installation of this machine.
Unauthorised repairs to this equipment may
endanger the technician and operator and will
void your Warranty. Only qualified personnel
approved by R-Tech Welding should perform
repairs.
Always disconnect mains power before
investigating equipment malfunctions.
Parts that are broken, damaged, missing or
worn should be replaced immediately.
Equipment should be cleaned periodically.
PLEASE NOTE that under no circumstances
should any equipment or parts be altered
or changed in any way from the standard
specification without written permission given
by R-Tech Welding.To do so, will void the
Equipment Warranty.

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2.1 Introduction
The Tungsten Inert Gas, or TIG process, uses
the heat generated by an electric arc struck
between a non-consumable tungsten electrode
and the workpiece to fuse metal in the joint
area and produce a molten weld pool.The arc
area is shrouded in an inert or reducing gas
shield to protect the weld pool and the non-
consumable electrode.The process may be
operated autogenously, that is, without filler, or
filler may be added by feeding a consumable
wire or rod into the established weld pool.
2.2 Process
Direct or alternating current power sources
with constant current output characteristics
are normally employed to supply the welding
current. For DC operation the tungsten may
be connected to either output terminal, but
is most often connected to the negative pole.
The output characteristics of the power source
can have an effect on the quality of the welds
produced.
Shielding gas is directed into the arc area by the
welding torch and a gas lens within the torch
distributes the shielding gas evenly over the
weld area. In the torch the welding current is
transferred to the tungsten electrode from the
copper conductor.The arc is then initiated by
one of several methods between the tungsten
and the workpiece.
2.3 Process Variables
DCEN
When direct-current electrode-negative
(straight polarity) is used:
Electrons strike the part being welded at a
high speed.
Intense heat on the base metal is produced.
The base metal melts very quickly.
Ions from the inert gas are directed towards
the negative electrode at a relatively slow rate.
Direct current with straight polarity does not
require post-weld cleaning to remove metal
oxides.
2.0 Gas Tungsten Arc Welding
(GTAW/TIG)

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Use of DCEN
For a given diameter of tungsten electrode,
higher amperage can be used with straight
polarity. Straight polarity is used mainly for
welding:
Carbon steels
Stainless steels
Copper alloys
The increased amperage provides:
Deeper penetration
Increased welding speed
A narrower, deeper, weld bead.
DCEP
The DCEP (reverse polarity) are different from
the DCEN in following ways:
High heat is produced on the electrode rather
on the base metal.
The heat melts the tungsten electrode tip.
The base metal remains relatively cool
compared to sing straight polarity.
Relatively shallow penetration is obtained.
An electrode whose diameter is too large will
reduce visibility and increase arc instability.
Use of DCEP
Intense heat means a larger diameter of
electrode must be used with DCEP.
Maximum welding amperage should be
relatively low (approximately six times lower
than with DCEN).
Alternating Current with High-Frequency
Welding with alternating current
Welding with alternating current combines both
direct-current characteristics:
In the positive phase, cleaning action occurs in
the weld puddle.
During the negative phase, heat is
concentrated in the weld puddle.
The above causes increased penetration.

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2.4 Shielding Gas Selection

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2.5 Consumable Selection
a) Welding wire
The following table includes the recommended
welding consumable for the most commonly
welded materials.

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2.6 Welding Techniques
2.7 Torch Movement During Welding
2.8 Positioning Torch Tungsten for Various Weld Joints

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12

13
2.9 Joint Preparation

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3.0 TIG Welding of Materials
3.1 Application Summary

18
3.2 C-Mn Steel
TIG welding may be used for welding carbon
steel but because deposition rates are low, it
is usually only used for welding sheet and thin
sections for high quality applications, small
components, and root passes of multipass butt
joints in plate and pipe.
Standard DC TIG equipment is normally
suitable and DCEN polarity is usually chosen to
provide good workpiece heating.
Only inert or reducing gases should be used
for TIG welding and pure argon is normally
recommended as the shielding gas for steel.
Filler rods are usually selected to match the
chemical composition and the mechanical
properties of the parent plate.The weldability of
the steel may impose restrictions on the choice
of filler rod.
Steels with carbon contents above about 0.3%
are hardenable, and fast cooling will produce a
hard HAZ and this is liable to result in
hydrogen cracking.This form of cracking can
be prevented by use of preheat and suitable
welding procedures.