HTP Invertig 221 AC/DC User manual

Invertig 221 AC/DC
Invertig 221DV AC/DC
Owner’s Manual
180 Joey Drive · Elk Grove Village, IL 60007 · Ph: 847-357-0700 · Fax: [phone] · Web: www.usaweld.com

2
Index
Manufacturer’s Warranty 3
Safety Suggestions 4
Front & Rear Panel Connections & Controls 5
Front Panel Controls
Welding Parameter Section 6-10
Welding Mode Section 11-15
Tungsten Electrodes 16
General Welding Parameters & Quick Set Up 17
Filler Rod 18
TIG Torch Consumables 19-23
Specialty TIG Torch Necks 24
Invertig 221 AC/DC (Single Voltage) Parts Diagram & List 25
Invertig 221 AC/DC (Single Voltage) Wiring Diagram 26
Invertig 221DV AC/DC (Dual Voltage) Parts Diagram & List 27
Invertig 221DV AC/DC (Dual Voltage) Wiring Diagram 28

Manufacturer’s Warranty
It is expressly agreed that there are no warranties, expressed or implied, made by either the
Salesman, Dealer, or HTP America, Inc. on products or parts furnished hereunder, except the
Manufacturer’s Warranty against defective materials or workmanship as follows:
HTP America, Inc. warrants each new welding machine to be free from defects in material
and workmanship under normal use and service for three years after delivery to the original
purchaser. HTP America, Inc. will repair and replace, at its factory, any part or parts thereof,
products to be returned to HTP America, Inc. with transportation charges prepaid and which
its examination shall disclose to its satisfaction to have been thus defective. This warranty
being expressly in lieu of all other warranties, expressed or implied, and all other obligations
or liabilities on its part and it neither assumes nor authorizes any other person to assume for it
any other liability in connection with the sale of its machines.
This warranty shall not apply to any welding machine which has been repaired or altered
by unauthorized service departments in any way so as in the judgment of HTP America, Inc.
to aect its stability and reliability, nor which has been subjected to misuse, negligence
or accident.
HTP America, Inc. shall not be liable in any event, unless HTP America, Inc. receives notice
of alleged breach of warranty within not more than 30 days after the discovery, actual or
construction alleged breach of warranty specifying the claimed defect.
HTP America, Inc. has reserved the right to make change in design or add any improvements
to its products at any time without incurring any obligation to install same on equipment.
This warranty is void unless warranty card is sent to HTP America, Inc. within 15 days from
date of purchase.
Note:
Exclusions to Warranty:
1. The TIG Welding Torch is warranted for a period of ninety (90) Days against
defects in material and workmanship.
2. The tungsten, collet, collet body, ceramic nozzles are consumable items, WHICH CARRY
NO WARRANTY.
3
This warranty is to the original purchaser only. The warranty can be transferred to
another owner, with HTP's approval, for a warranty transfer fee. HTP America, Inc. must
be notified within fourteen (14) days of the sale and must be provided with the contact
information of the original owner, the contact information of the new owner, and the
serial number of the machine.
3.

Safety Suggestions
Electric arc welding produces ultra-violet rays, which are harmful to skin and eyes. Ultra-violet radiation
can penetrate lightweight clothing, reect from light colored surfaces, and burn the skin and eyes. Wear
ameproof welding gloves which are not oily or greasy. The oil or grease on the gloves may ignite. Wear a
heavy, pocket-less, long sleeve shirt, cuess trousers, and high-topped work shoes. Wear a full-face welding
helmet with a number eight or darker lens and a cap. These precautions will protect eyes, hair, face, and skin
from arc rays and hot material.
For more information, refer to the following standards and comply as applicable.
1. ANSI Standard Z49.1 SAFETY IN WELDING AND CUTTING, obtainable from the
American Welding Society, 2051 NW 7th St., Miami, FL 33125.
2. ANSI Standard Z87.1 SAFE PRACTICE FOR OCCUPATION AND EDUCATIONAL EYE AND FACE
PROTECTION, obtainable from American National Standards Institute, 1430 Broadway,
New York, NY 10018.
3. America Welding Society Standard A6.0 WELDING AND CUTTING CONTAINERS WHICH
HAVE HELD COMBUSTIBLES, obtainable same as item 1.
4. NFPA STANDARD 51. OXYGEN-FUEL GAS SYSTEMS FOR WELDING AND CUTTING, obtainable from
the National Fire Protection Assoc., 470 Atlantic Avenue, Boston, MA 02210.
5. NFPA Standard 51B. CUTTING AND WELDING PROCESSES, obtainable same as item 4.
6. CGA PAMPHLET P-1. SAFE HANDLING OF COMPRESSED GASES IN CYLINDERS, obtainable from
the Compressed Gas Association, 500 Fifth Avenue, New York, NY 10036.
7. OSHA Standard 29 CFR, Part 1910, Subpart Q WELDING, CUTTING AND BRAZING.
• To avoid re, do not weld on wood, plastic tile, or
carpeted oors. Concrete or masonry oors are safest.
• Do not weld on drums, barrels, tanks or other containers
until they have been cleared as described in AWS
Standard A6.01.
• Provide adequate ventilation in the welding area at all
times. Do not weld on galvanized zinc, cadmium or lead
beryllium materials unless you are POSITIVE sucient
ventilation is provided. These materials produce toxic fumes.
•
Do not weld in areas close to degreasing or spraying opera-
tions. Chlorinated hydrocarbon vapors may react with the
ultra-violet rays and form highly toxic phosgene gas.
• If you develop momentary eye, nose or throat irritation
during welding, stop welding immediately. This is an
indication that ventilation is not adequate. Do not
continue to weld until ventilation is improved.
• Exposed, electrically hot conductors or other bare metal
in the welding circuit, or ungrounded electrically hot
equipment can fatally shock a person whose body
becomes a conductor. Do not stand, sit, lie, lean on or
touch a wet surface when welding.
• Frequently inspect cables for wear, cracks, and damage.
Replace those with excessively worn insulation to avoid
a possible lethal shock from bared cable.
Electrical Connection
Your Invertig 221 AC/DC operates on single-phase, 230 volt
power (+/- 15%). The machine is shipped with a plug. The
input power cord has 3 wires. The green wire is ground,
and the black and white wires are the hot leads.
The machine draws 36 amps out of the wall when operat-
ing at a welding output of 220 amps in the TIG mode and 44
amps when welding at an output of 200 amps in the stick
mode.
The Invertig 221 DV has the ability to operate on either 110 or
230 volts. All you need to do is change the plug. When wiring
the machine for 110 volts, you typically use an adapter cable
fitted with a 110 volt plug on one end and a 220 volt female
receptacle, one that matches the 220 volt plug on your
machine's power cord, on the other.
On 230 volts, the machine draws 26 amps out of the wall
when operating at a welding output of 220 amps in the TIG
mode and 32 amps when welding at an output of 200 amps in
the stick mode.
On 110 volts, the maximum output is 155 amps. The output
must be limited to 130 amps in the TIG welding mode to run
on a 30 amp breaker, 85 amps to run on a 20 amp breaker, and
67 amps to run on a 15 amp breaker. In the stick mode, the
output must be limited to 100 amps to run on a 30 amp
breaker, 65 amps to run on a 20 amp breaker, and 50 amps to
run on a 15 amp breaker.
All electrical connections should be performed by a
qualied electrician in accordance with the National
Electrical Code and local codes and ordinances.
4

1. Negative Output Receptacle
When TIG welding, this is where the TIG Torch connects to your
Invertig 221 Welder. That’s right, we said the TIG Torch. This is
called straight polarity, with the torch negative and the work
positive. When using your Invertig Welder to TIG weld, all work
will be done in straight polarity.
When Stick Welding Direct Current Electrode Negative (DCEN),
the optional electrode holder will be plugged into the nega-
tive output receptacle. When Stick Welding Direct Current
Electrode Positive (DCEP), the ground cable will be plugged
into the negative output receptacle
To install a cable into the negative output receptacle, insert
the male end of the cable into the negative output receptacle
and twist clockwise until snug.
2. Gas Output Connection
This is where you connect the gas tting from the TIG Torch.
The gas output is controlled by the solenoid valve, which is
mounted inside the welder.
3. 7- Pin Connection
The 7-pin connection is where your remote amperage control
would connect to your 221. This is also where you would con-
nect a momentary contact switch. Insert the connection into
the machine and twist the lock ring clockwise until snug.
I have found it is easiest to connect the remote rst, the gas
second, and the positive and negative receptacles last.
4. Positive Output Receptacle
When TIG welding, this is where the ground cable connects to
the front of the TIG Adapter. That’s right, we said the ground
cable. This is called straight polarity, with the torch negative
and the work positive.
When Stick Welding Direct Current Electrode Negative (DCEN),
the ground cable will be plugged into the positive output
receptacle. When Stick Welding Direct Current Electrode
Positive (DCEP), the electrode holder will be plugged into
the positive output receptacle.
To install a cable into the positive output receptacle, insert
the male end of the cable into the positive output receptacle
and twist clockwise until snug.
1. On-O Switch
This switch controls the input power to your Invertig Welder.
0 is o and 1 is on.
2. Gas Inlet Connection
Connect the female end of your gas hose to the inlet gas
connection and the male end of your gas hose to your owmeter.
Shield Gas
TIG welding requires a shield gas of 100% Argon. A shield gas
is used to keep the surrounding atmosphere from coming in
contact with the molten weld puddle. The correct ow rate is
enough gas to shield the molten weld puddle and protect the
tungsten electrode. Any greater ow rate is a waste of shield
gas. Usually, the flow rate will be set anywhere between
15 and 30 cubic feet per hour (CFH).
Use a gas regulator such as HTP Part #12020 which is
compatible with Argon cylinders and has a barbed tting
for the delivery hose.
Argon/helium mixtures can be used to increase penetration.
Argon/helium mixes with high (more than 50%) helium
content will give you difficulties starting the arc, as well as arc
stability issues. As far as added headed into the weld puddle,
there are no real advantages to running mixtures with more
than 50% helium in AC mode. If you will be welding thick
aluminum castings such as an aluminum cylinder head, ultra
high purity helium can be used. If you are welding thick
aluminum sections like cylinder heads and engine blocks, and
you do not want to preheat the part, you can weld these items
in DC using ultra high purity helium, to achieve maximum
penetration without pre-heating. Since there is no AC
cleaning cycle, it is important proper cleaning practices are
followed.
3. Input Power Cord – this is where the input power cord
passes through the rear of the cabinet.
4. 220V & 110V/220V Water-Cooler Connection – This is the
electrical connection where a 220V or 110 V/220V water-
cooler will connect to your Invertig 221/Invertig 221DV. If you
have an Invertig 221DV, the water-cooler will operate with the
Invertig 221DV connected to either 110V or 220V power. The
water-cooler, like the Invertig 221 DV, auto senses the input
power voltage.
Figure 1
FRONT PANEL CONNECTIONS REAR PANEL CONTROLS AND CONNECTIONS
Figure 2
12
4
3
1 2 3 4
5

1) Encoder – All of the welding parameters are adjusted
using the encoder. Turning the encoder clockwise increases
the setting and counter clockwise decreases it. The encoder
adjusts all of the functions of your 221.
2) Function Button – the function button allows you to
select between the 7 dierent welding parameters. The
default setting is A (2D) amperage. When the green light is
illuminated under the “A” setting (2D) as shown in Photo 1,
you can adjust the amperage using the Encoder (1). The
amperage can be adjusted between 4 and 220 amps in any of
the TIG welding modes and between 4 and 200 amps in the
stick welding mode.
2A – Pre Gas – Depressing the function button until the
“pre gas” light (2A) is illuminated will allow you to adjust the
pre-gas setting. As shown in Fig 4, the pre gas light (2A) is
illuminated and the amps display will ash “PrG”. While the
display is ashing, the pre gas time will be displayed in the
“AMPS” digital display in seconds. Use the encoder to
adjust the pre-gas from .1 sec to 2.0 sec in .1 sec increments
while the display is flashing.
Pre-gas is the amount of time the gas flows before the
arc has been ignited. This ensures there will be no weld
contamination from air, since the weld area will be purged with
shielding gas prior to welding. A good starting value is .4 sec.
Welding Parameter Section
FRONT PANEL CONTROLS
The front panel controls will be split into 2 sections – the welding mode section and the welding parameter
section. The welding mode section covers the different welding modes – such as Stick Welding, TIG 2T
welding and so on. The welding parameter section covers all the different adjustments such as pre-gas, post
gas, slope down and so on.
4321FED
4a
4b
2a 2b 2c 2d 2e 2f 2gCBA
D1
D2
D3
D4
D5
Figure 4
2a
6
21

2B - Starting Current - Depressing the function button (2)
until the “starting current” light (2B) is illuminated will allow
you to adjust the starting current in %. As shown in Fig 5,
the starting current light (2B) is illuminated and the amps
display will ash “ILS”. While the display is ashing, the
starting current will be displayed in the “AMPS” digital
display in percent of the peak welding current. Use the
encoder (1) to adjust the starting current from 10% to 90%
in 1% increments while the display is ashing.
2C – Slope Up - Depressing the function button (2) until the
“slope up” light (2C) is illuminated will allow you to adjust
the slope up setting. As shown in Fig 6, the slope up light
(2C) is illuminated and the amps display will ash “SLu” for
slope up. While the display is ashing, the slope up time will
be displayed in the “AMPS” digital display in seconds. Use
the encoder to adjust the slope up from .1 sec to 2.0 sec in
.1 sec increments while the display is ashing.
Slope up is the amount of time it takes the welder to reach
the peak current from the starting current.
2D – Peak Current (AMPS) - When the green light is illuminated
under the “A” setting (2D) as shown in Fig 7, you can adjust the
amperage using the Encoder (1). The amperage can be adjusted
between 4 and 220 amps in any of the TIG welding modes and
between 4 and 200 amps in the stick welding mode. This is the
default setting for the welding function button.
2E – Slope Down - Depressing the function button (2) until the
“slope down” light (2E) is illuminated will allow you to adjust
the slope down setting. As shown in Fig 8, the slope down
light (2E) is illuminated and the amps display will flash “SLd”.
While the display is flashing, the slope down time will be
displayed in the “AMPS” digital display in seconds. Use the
encoder to adjust the slope down from .1 sec to 2.0 sec in .1 sec
increments while the display is ashing.
Fig 8
Slope down is the amount of time it takes the welder to reach
the final current from the peak current. This setting is used to
allow the molten weld puddle to solidify gradually to help
prevent a crater from forming.
2F - Final Current - Depressing the function button (2) until
the “nal current” light (2F) is illuminated will allow you to ad-
just the nal current in %. As shown in Fig 9, the nal current
light (2F) is illuminated and the amps display will ash “ILo”.
While the display is ashing, the nal current will be displayed
in the “AMPS” digital display in percent of the peak welding
current. Use the encoder to adjust the nal current from 10%
to 90% in 1% increments while the display is ashing.
Figure 7
2D
21
21
2C
Figure 6
Figure 5
2B
7
21
Figure 8
2E
2
1
Figure 9
2F
2
1

AC Frequency
Depress the “SET AC” button (4) once. As shown in Fig 12, the
frequency light (4A) will flash and the amps display will flash
“F.AC”. While the display is flashing, the frequency will be
displayed in the “AMPS” digital display in Hz (Cycles per second).
Use the encoder (1) to adjust the AC frequency from 20 Hz to
200 Hz in 1 Hz increments while the display is flashing.
Higher AC frequencies focus the arc cone more to a point and
give you greater arc control with less arc wandering. Lower AC
frequencies increase the overall heat input in the material to
weld thicker sections of aluminum.
2G – Post Gas – Depressing the function button (2) until the
“post gas” light (2G) is illuminated will allow you to adjust the
post-gas ow. As shown in Fig 10, the post gas light (2G) is
illuminated and the amps display will ash “PrG”. While the
display is ashing, the post gas time will be displayed in the
“AMPS” digital display in seconds. Use the encoder to adjust
the post gas from .1 sec to 30.0 sec in .1 sec increments while
the display is flashing.
Fig 10
Post gas is the amount of time the gas flows after the arc
has been extinguished. This ensures there will be no weld
contamination from the atmosphere while the weld puddle
cools, since the weld area will be purged with shielding gas
after welding. A good starting value is 6 sec. The larger the
tungsten diameter and the higher the amperage, the longer
the post gas ow needs to be.
3) AC Welding Mode - Depressing the AC welding mode
button (3) will illuminate the green “AC ON” light indicating
your Invertig 221 is in the AC welding mode as shown in Fig 11.
If the AC ON light is ashing, it indicates you have independent
AC amperage adjustment engaged.
Fig 11
To turn the AC Welding Mode o, depress the AC Welding
Mode button for at least 3 seconds until the green AC welding
mode light goes out.
For welding aluminum and magnesium, you want the “AC ON”.
For steel, stainless steel, 4130 tubing, and all other materials,
you want the AC welding mode o.
4) Set AC
The “Set AC” button (4) allows you to adjust the AC welding
parameters when the machine is in the AC welding mode.
The parameters which can be adjusted are AC Frequency,
AC Balance, Electrode Negative welding amperage and
Electrode Positive welding amperage.
Figure 11
8
3
Figure 10 1
2G
2
Chart 12a
In chart 12A you can see the eect the AC Frequency has on
the square wave. The 20 Hz wave is shown at the top. The
AC wave changes from electrode positive to electrode
negative 20 times a second. In the bottom you see a 200 Hz
wave – The AC wave changes from electrode positive to
electrode negative 200 times a second – 10 times faster than
the 20 Hz wave. The higher AC frequency focuses the arc
cone more to a point, allows you to maintain a point on the
tungsten, a gives you greater arc control with less arc wander-
ing. I try to picture this graph in my head when I change the
AC frequency so I can understand how I am changing the
wave and the arc characteristics.
1
4A
1 4
Figure 12

AC Balance
Depress the “SET AC” button (4) twice. The balance light (4B)
will flash and the volts display will flash “b.AC”. While the
display is flashing, the AC balance will be displayed in the
“VOLTS” digital display in %. Use the encoder (1) to adjust the
AC balance from 10% to 90% in 1 % increments while the
display is flashing.
A higher AC balance percentage gives you more electrode
negative, so you get more penetration, less cleaning, and your
tungsten runs cooler. A lower AC balance gives you more
electrode positive, which is more cleaning, less penetration,
but your tungsten runs hotter.
9
Figure 12b
Chart 12d
Chart 12e
Chart 12C shows 60 Hz AC wave with the AC balance set to
50%. This is called a balanced square wave. The amount of
time the electrons ow from the torch to the work, and then
from the work to the torch, is equal.
Chart 12c
If you remember from the front panel connections, the ground
cable is in the positive output receptacle and the torch is in the
negative. Chart 12D shows the AC balance set to 10%. For
10% of the time, the torch is negative and the electrons ow
from the torch to the work piece. The ow of electrons from
the torch to the work is the penetration cycle. The other 90%
of the time, the torch becomes positive and the work becomes
negative, and the electrons jump from the work to the tung-
sten. This ow of electrons from the work to the torch is the
cleaning cycle. The electrons literally blow the impurities o
the molten puddle. So when the AC Balance is set to 10% the
machine is set for maximum cleaning. You have to remem-
ber with the balance set this low, you are putting an extreme
amount of heat into your tungsten, and you will probably see
a 1/8” tungsten melt at less than 50 amps. One application
where you may want more cleaning (lower AC Balance) would
be if you were welding on a dirty casting.
Chart 12E shows the AC balance set to 90%. For 90% of the
time, the torch is negative and the electrons flow from the
torch to the work piece. The flow of electrons from the torch to
the work is the penetration cycle. The other 10% of the time,
the torch becomes positive and the work becomes negative,
and the electrons jump from the work to the tungsten. This
flow of electrons from the work to the torch is the cleaning
cycle. So when the AC Balance is set to 90% the machine is set
for maximum penetration. Higher AC balances put less heat
into the torch, and more heat into the work. An application
where you may want more penetration (higher AC Balance)
would be if you were trying to weld a heavier section than you
could normally weld with 220 amps – say something in the
3/8 to ½” range. Setting the balance to 90% may allow you to
make this weld, depending on the application. It is important
to note, that with less cleaning it is critical to clean the
piece properly.
4B
Figure 12B 14

Depress the “SET AC” button (4) once, release, then press again
and hold. As shown in Fig 13, the balance light (4B) will rapidly
ash and the amps display will ash “En-” and the machine will
beep once. Release the “SET AC” button, and while the display
is ashing, the electrode negative amperage will be displayed
in the “AMPS” digital display in % of peak current. Use the
encoder (1) to decrease the electrode negative amperage from
10% to 90% of the peak amperage in 1 % increments while the
display is ashing.
Whenever the AC amperage has been independently adjusted,
the “AC ON” light will ash. To exit independent AC amperage
adjustment, hold the “SET AC” button in until the balance light
goes out and the AC ON light glows continuously.
10
Electrode Negative AC Amperage Adjustment
Figure 13
4B
4
1
Electrode Positive AC Amperage Adjustment
Fig 14
Depress the “SET AC” button (4) once, release, then press
again and hold. As shown in Fig 14, the balance light (4B)
will rapidly ash and the amps display will ash “En-”.
Continue to hold the “SET AC” button, and a number will come
in the display, and then the amps display will ash “EnP” and
the unit will beep twice. Release the “SET AC” button, and
while the display is ashing, the electrode positive amperage
will be displayed in the “AMPS” digital display in % of peak cur-
rent. Use the encoder (1) to reduce the electrode positive am-
perage from 10% to 90% in 1% increments while the display is
flashing.
Whenever the AC amperage has been independently adjusted,
the “AC ON” light will ash. To exit independent AC amperage
adjustment, hold the “SET AC” button in until the balance light
goes out and the AC ON light glows continuously.
Figure 14
4B
14
Chart 13A
Chart 14A
Chart 13 A shows the effect of reducing the Electrode Negative
Current on the square wave. You can see this is a balanced
square wave (AC Balance = 50%) which means the time
welding in electrode positive and electrode negative is the
same. What we are changing is the amperage. By reducing the
electrode negative amperage, we are putting less heat into
the work piece, there will be less penetration, the bead will be
wider, and there will be more cleaning. This will also put more
heat into the tungsten, so the tungsten may need to be
sharpened more frequently.
Chart 14 A shows the eect of reducing the Electrode
Positive Current on the square wave. You can see this is a
balanced square wave (AC Balance = 50%) which means the
time welding in electrode positive and electrode negative is
the same. What we are changing is the amperage. By reducing
the electrode positive amperage, we are putting less heat into
the tungsten which will result in longer tungsten life. The arc
cone will be narrower, there will be more penetration, the bead
will be narrower, and there will very little visible cleaning at the
weld toe.

A) Power Indicator Lamp
This lamp is illuminated when the On-O switch on the
back of your Invertig 221 is turned to the 1 or “On” position,
indicating the unit is correctly connected to 220 volt AC power.
B) Welding Current Indicator Lamp
When either the foot pedal or the trigger switch on the TIG
torch is depressed, welding current will be applied to the
welding torch and the Welding Current Indicator Lamp will
be illuminated.
If your Invertig 221 AC/DC is in the stick-welding mode, the
welding current indicator lamp will be illuminated all the time.
C) Thermoswitch Indicator Lamp
The thermoswitch indicator lamp will light up when the duty
cycle of your Invertig 221 AC/DC has been exceeded. When
this lamp is illuminated, the machine will no longer weld
because the machine has overheated. Leave the machine
plugged in and turned on so the cooling fans can cool the
unit down. Allow the machine to cool for 15 to 30 minutes,
the thermoswitch should reset automatically and your
Invertig will be ready to weld.
D) Welding Mode Switch
The welding mode push button allows you to select the
welding mode of your Invertig 221 AC/DC.
D1) Stick Welding Mode
Depressing the welding mode button (D) until the “stick” light
(D1) is illuminated will activate the “stick welding mode”. This
mode is used for SMAW (stick electrode or arc) welding. As
shown in Fig 16, the stick light (D1) is illuminated and the amps
display will ash “Arc”. When the display stops ashing, the
welding current will be displayed in the “AMPS” digital display,
and the welding voltage will be displayed in the “VOLTS”
digital display.
The only parameter you can adjust is the amperage. Hot start
and arc force are not adjustable. The machine will run all types
of electrodes including 6010.
You can stick weld in both AC and DC. When stick welding in AC,
all AC functions are adjustable – AC Frequency, AC Balance and
independent AC amperage adjustment. The pulse function is
also fully functional in the stick weld mode from 0.4Hz to 5Hz.
The electrode will always be hot and the gas solenoid will not
operate. The green “Welding Current” lamp will be illuminated
indicating the welding current is on.
11
4321FED
4a
4b
2a 2b 2c 2d 2e 2f 2gCBA
D1
D2
D3
D4
D5
Welding Mode Section
Figure 16
D1
D
If you do not plan to use a remote control (hand or foot) for
amperage adjustment while stick welding, remove the remote
control. If you do not remove the remote control, the machine
reverts to the start-up amperage (generally 4 amps) when you
strike an arc, whether or not you manually set the amperage at
the machine.
V.R.D. (Voltage Reduction Device) is a system which reduces the no-
load voltage to a lower and safer voltage (normally less than 18 volts.
Used as an additional aid for operator safety and for when safety
procedures at work require protection. The V.R.D. function not only
makes the welding machine safer, but also makes the stick welding
rods harder, or even very hard in some cases, to light. To activate the
V.R.D., hold down the MODE button for approximately 5 seconds, and
then release the button. The Stick welding mode LED flashes
indicating the V.R.D. is activated. To deactivate the V.R.D., hold down
the MODE button for approximately 5 seconds, and then release the
button. The Stick welding mode LED stops flashing and illuminates
solidly, indicated the V.R.D. is deactivated.

D2) TIG 2T Mode – From the Stick Mode, depressing the
welding mode button (D) once will put you in the “2T” Mode.
T his mode will be used when welding with a remote amperage
control. As shown in Figure 17, the 2T light (D2) is illuminated
and the amps display Figure “t.2”. When the display stops ash-
ing, the peak welding current will be displayed in the “AMPS”
digital display, and the welding voltage will be displayed in the
“VOLTS” digital display (00.0 unless you are welding).
With the torch trigger or foot pedal depressed, your
Invertig 221 will start the arc. When the trigger or foot pedal
is released, the unit will stop. Select this welding mode for
operation with the foot pedal or the torch mounted amperage
control. This will generally be the most common mode
of operation.
Welding parameters which can be adjusted using the encoder
in the 2T mode are pre-gas (2A), slope down (2E), and post
gas(2G).
D3) TIG 4T mode – From the 2T Mode, depressing the welding
mode (D) button once will put you in the “4T” Mode (D3). This
is like a lock on trigger on a drill or grinder. This mode is gener-
ally used with a TIG torch which has a trigger to start and stop
the arc. It is not used with a foot pedal or a torch mounted
amperage control.
As shown in Fig 18, the 4T light (D3) is illuminated and the
amps display will ash “t.4”. When the display stops ash-
ing, the peak welding current will be displayed in the “AMPS”
digital display, and the welding voltage will be displayed in the
“VOLTS” digital display (00.0 unless you are welding).
When you depress the trigger on the torch, your Invertig 221
provides pre-gas ow for as long as the trigger is depressed.
When the trigger is released, it will slope up to the welding
amperage that has been selected. When the trigger is
depressed again, the welding current will slope down to the
nal current. As long as the trigger is depressed, your Invertig
221 will continue to weld at the nal current which has been
selected. When the trigger is released, the arc will extinguish,
and the post ow will start.
Welding parameters which can be adjusted using the
encoderare slope down (2E), nal current (2F), slope up (2C),
starting current (2B), pre-gas (2A), and post gas (2G).
Again, we do not recommend using the 4t mode with either
the foot pedal or the torch mounted amperage control.
D4) TIG SPOT – From the 4T Mode, depressing the welding
mode (D) button once will put you in the “Tig Spot” (D4) Mode.
The spot welding mode allows you to weld for between 0.1
and 10 seconds and then the unit will automatically stop. This
would be a good selection if you were performing a series of
repetitive tack welds.
As shown in Fig 19, the “TIG SPOT” light (D4) is illuminated and
the amps display will ash “Pun” for point or spot. When the
display stops ashing, the peak welding current will be dis-
played in the “AMPS” digital display, and the welding voltage
will be displayed in the “VOLTS” digital display (00.0 unless you
are welding).
To adjust the spot welding time, press the “FUNCTION” button
once and the amps display will ash “tin” for time. (the display
can’t form an “m”) When “tin” disappears the number in “AMPS”
digital display will show the spot weld time. Using the Encoder
(1) select a spot weld time between 0.1sec and 10.0 sec.
Welding parameters which can be adjusted are Spot time (2C),
final current (2F), pre-gas (2A), and post gas (2G). The spot
weld function works in AC and DC with or without pulse.
12
Figure 18
D3
2D
D
1 2
2G
2F
2E
2B
2A 2C
Figure 19
D4
21
2D 2G
2F
2A
2C
D
Figure 17 12
D
D2
2D
2G2E2A

D5) TIG REPEAT– From the TIG Spot Mode, depressing the
welding mode (D) button once will put you in the “TIG Reset”
Mode. Using a TIG torch which has a trigger switch, the TIG
Reset mode allows you to switch between 2 pre-programmed
welding amperages.
As shown in Fig 20, the “TIG REPEAT” light (D5) is illuminated
and the amps display will flash “riP” for TIG Repeat. When the
display stops flashing, the peak welding current will be
displayed in the “AMPS” digital display, and the welding voltage
will be displayed in the “VOLTS” digital display (00.0 unless you
are welding).
For example, you have your welding current set at 150 amps,
and your “FINAL CURRENT” set at 50% or 75 amps. Depress the
trigger and you have pre-gas ow for as long as you keep the
trigger depressed. Release the trigger and your TIG 221 will
begin to weld at 150 amps. Depress and release the trigger
and you will go to your nal current of 75 amps. Depress and
release the trigger again and you will go back to 150 amps.
To stop welding, depress the trigger for 5 seconds or longer.
When the trigger is released the arc is extinguished and the
machine will go into post gas ow.
Welding parameters which can be adjusted using the
encoder are slope down (2E), final current (2F), slope up
(2C), starting current (2B), pre-gas (2A), and post gas (2G).
E) HF ON – Depressing the “HF ON” button (E) so the green
light is illuminated turns the high frequency arc starting on.
When the foot pedal or torch trigger is depressed, a high
frequency arc will jump from the tungsten to the grounded
workpiece, initiating the arc. This makes it very easy to start
the arc, and also eliminates the possibility of tungsten contami-
nation from touching the work piece with the tungsten.
On your Invertig 221, in the AC mode, the high frequency is
only used to start the arc, unlike conventional transformer
welders which must have the high frequency on all the time
to maintain the arc.
When the high frequency is o, it is possible to do “lift arc”
starting. The lift arc mode allows you to initiate the welding arc
without high frequency. This is important in any environment
where the high frequency arc will cause interference with
sensitive electrical components or computers. A good
example of this would be stainless steel or aluminum repair
in hospitals. The Lift Arc mode works for both AC and DC
welding.
To TIG Weld using the Lift Arc Mode, simply touch the tungsten
to the workpiece, activate the torch trigger or depress the foot
pedal and lift o. When the tungsten breaks contact with the
work, the arc will start.
For Lift-Arc in aluminum, please remember the following
pointers to make arc ignition easier:
1) Keep the tungsten in contact with the workpiece for at
least 5 seconds before lifting o the work piece.
2) When using remote amperage control, it is advisable
to start the arc at a much higher amperage than the
actual welding amperage. Once the arc has been
established
, reduce the amperage to the welding amperage.
3) For Lift Arc at lower amperages, the correct tungsten
(2% Ceriated) correct diameter, and a correctly
ground tungsten are very important.
4) A higher frequency (200 Hz) and higher balance (90%)
will make it easier to initiate your arc.
F) PULSE ON – by depressing the “PULSE” button (F), the green
light will illuminate indicating your Invertig 221 is in the pulse
mode. At this time the “AMPS” display will show “P.Fr” for the
pulsing frequency. (See Fig 21)
Then a ashing number will come into the display which will
be the pulse frequency. While the number is ashing you can
adjust the pulse frequency using the encoder (1) from .4 PPS
(pulses per second) to 999 PPS in DC, and from .4 PPS to 10 PPS
in AC.
Depressing the “PULSE” button twice brings “P.du” into the
display. (See Fig 22) Then a flashing number will come into
the display which will be the pulse duty cycle or “peak welding
time” or just “peak time”. This is the percentage of the cycle
the machine will be welding at the “peak welding current”.
While the number is ashing you can adjust the peak time from
10% to 90% of the welding cycle in increments of 1%.
13
Figure 21 1F
E
Figure 20
D5
D
2D
2G
2F
2E
2B
2A 2C

The nal pulse welding parameter is the “background current”.
To adjust the background current, depress the “FUNCTION” (2)
button twice and “ILo” will appear in the display
(I for amperage and Lo for background).
Then a ashing number will come into the display which
will be the background current as a percentage of the peak
welding current. While the number is flashing you can adjust
the background current using the encoder (1) from 10% to 90%
of the peak welding current in increments of 1%.
So let’s do a common sense example. To make the math easy
we will set the pulse frequency (P.Fr) to 1.0 pulse per sec. We
will set the peak current (A) to 100 amps, the peak time to
(P.du) to 25%, and the background current (ILo) to 35%. Now
let’s assume we are hammer down on the pedal, so we are
welding at 100 amps. Your 221 will pulse once every second.
The peak time is set to 25%, so for 25% of your 1 second pulse
(¼ sec (.25 sec)) your 221 will be welding at 100 amps. The
back ground current is set to 35%, or 35% of 100 amps, which
is 35 amps. So for the remainder of the pulse, (3/4 sec (.75
sec)) the machine will drop down to the background current
which is 35 amps. It will then repeat the cycle.
It is important not to set your background current too low, or
the peak time too short or the weld puddle may freeze, which
could cause cracking.
To turn o the pulse mode, depress the “PULSE” (F) button
at least 3 seconds until the green pulse light goes o.
Welding Volts - Digital Display
The Welding Volts Digital Display is a multi-function display.
When you are welding, this displays the welding voltage.
Pressing other touch pad buttons will display other parameters
in the “VOLTS” display. Those displays will be covered in the
section covering those touch pad buttons.
Welding Amps - Digital Display
The Welding Amps Digital Display is a multi-function display.
When you are welding, this displays welding amperage.
Pressing other touch pad buttons will display other parameters
in the “VOLTS” display. Those displays will be covered in the
section covering those touch pad buttons.
Adjusting the Starting Current – There may be times when
you want the starting current to start at a higher setting than
the default starting current which is 4 amps when welding in
the 2 t mode and using a remote amperage control.
Fig 24
To change the starting current, depress the “FUNCTION” but-
ton (2) until “oFS” appears in the amperage display. When
“oFS” appears in the display, release the FUNCTION button,
and while the display is flashing, adjust the starting current
using the encoder (1). The starting current can be adjusted
from 4 to 100 amps in increments of 1 amp. Do not set the
starting cur-rent higher than your peak current.
14
Figure 22 1F
Figure 23 2
1F
2F
Figure 24 2
1

Storing Welding Programs – Your Invertig 221 will store 64
separate welding programs which you can recall for specic
welding jobs. You will see under the “FUNCTION” button (2)
and the “AC MODE” button (3) it says “job mode – enter/exit”.
First, make sure all the parameters you want to store are set
on your 221. The machine must be set beforehand.
To enter the job mode, depress the function button (2) rst
and then AC Mode button (3) second, and keep both buttons
depressed until the machine beeps twice and “PrG” comes
into the volts display, and a number between 1 and 64 comes
into the amps display (see g 25). You can use the encoder (1)
to adjust the program from anywhere between 1 and 64. The
number in the display is where your welding program will be
stored. For this example, let’s set the program to 1.
Insert Fig 26 here
Next, depress “MODE” (stor. job) button (D) and keep it
depressed. “Sto” will ash and come into the volts display
and the amps display will show the program number. Keep
the “MODE” button depressed and you will hear the machine
beep. When is starts beeping release the mode button. The
machine will beep a total of 4 times and when nished your
program will be stored.
We strongly advise you keep track of your welding programs
by writing them down or by putting them in an excel
spreadsheet.
15
Recalling Welding Programs – to recall welding programs,
enter the job mode by depressing the function button (2) rst
and then AC Mode button (3) second, and keep both buttons
depressed until the machine beeps twice and “PrG” comes into
the volts display. Using the encoder (1) adjust the volts display
to the number you want to recall.
Insert Fig 27 here
Depress the “HF” (set job) button (E) and hold. The machine
will beep and “rEc” will flash in the volts display. Keep the set
job button depressed until the machine beeps again and
release. The machine will continue to beep and when it stops,
your program will be recalled.
Figure 25 2
13
Figure 26
D
Figure 27
1
E

16
Tungsten Electrodes
With conventional transformer TIG welders, the general rule of
thumb is to use a pure tungsten (identified by a green tip) for
AC welding (generally aluminum), and a 2% thoriated tungsten
(identified by a red tip) for DC welding (generally steel
welding). However, with an inverter TIG welder, the ability to
control the frequency and balance over a much wider range
allows you to take advantage of the new “rare earth” tungsten
which is now available.
A 2 % Ceriated tungsten is the best tungsten selection for both
AC and DC welding with your new HTP Invertig 221.
HTP offers the following premium quality tungsten ground
to a high quality finish. All tungsten is 7" long and can be
purchased individually.
Pure Tungsten (TP): green tip - Pure tungsten readily forms
a ball on the end. It is generally used with transformer based
power sources for AC welding of aluminum.
2% Thoriated Tungsten (TT2): red tip - This tungsten is the
most common tungst en currently used. Generally used for DC
welding of steel and stainless steel. Draw back is it has a low
level radiation hazard. Oers good overall performance.
2% Ceriated Tungsten (TC2): grey tip - 2% ceriated is an
excellent substitute for 2% thoriated tungsten if you are using a
transformer based power source for DC welding. More popular
for thinner materials because it requires less amperage to start.
Offers a stable arc. Can be used for both AC and DC welding
with inverter power sources.
2% Lanthanated Tungsten (TL2): blue tip – 2% lanthanated
is probably the most popular substitute for 2% thoriated
tungsten. It offers good arc starting characteristics and longer
life than 2% thoriated. Can be used for both AC and DC
welding with both inverter and transformer power sources.
Tungsten Type Diameter
.040" 1/16" 3/32" 1/8"
(1.0mm) (1.6mm) (2.4mm) (3.2mm)
Pure Tungsten TP-7040 TP-7116 TP-7332 TP-718
2% Thoriated TT2-7040 TT2-7116 TT2-7332 TT2-718
2% Ceriated TC2-7040 TC2-7116 TC2-7332 TC2-718
2% Lanthanated TL2-7040 TL2-7116 TL2-7332 TL2-718
Amperage - AC 20-30 30-80 60-130 120-200
Amperage - DC 15-50 50-120 80-150 130-250
The electrode should be sharpened to a point with a fine
grinding wheel. If the stone used for sharpening the electrode
is not clean, contaminants could lodge in the electrode and
dislodge when welding. The grinding wheel used for tungsten
electrodes should not be used for any other materials. When
grinding the electrode to a point, a 15 to 30 degree angle is
desired. The grinding marks should run lengthwise with the
point, opposed to in the direction of the diameter.
The HTP Tungsten Sharpener is an excellent tool for
precisely sharpening tungsten electrodes without any fear
of contamination.
Tungsten Sharpener

General Welding Parameters
Following are some “rule of thumb” welding parameters,
tungsten diameters, and amperage settings for welding
dierent thicknesses of aluminum and steel. Keep in mind
these are general settings and the specific application may
require more or less power to get the job done.
Aluminum
Tungsten Machine Welding Filler
Thickness Diameter Amperage Amperage Diameter
.030" .040" 50 30-40 1/16"
.050" 1/16" 70 50-60 1/16"
.062" (1/16") 1/16" 80 65-75 1/16"
.093" (3/32") 3/32" 120 105-115 3/32"
.125" (1/8") 3/32" 150 125-135 3/32"
.187" (3/16")* 1/8" 170 150-160 1/8"
.250" (1/4")* 1/8" 200 180 1/8"
.312" (5/16)* 1/8" 220 220 1/8"
* May require beveling – depends on joint
Steel
Tungsten Machine Welding Filler
Thickness Diameter Amperage Amperage Diameter
.030" .040" 50 30-40 .035"
.050" 1/16" 70 45-55 .045"
.062" (1/16") 1/16" 80 55-65 1/16"
.093" (3/32") 1/16" 110 80-90 1/16"
.125" (1/8") 1/16" 130 110-120 1/16"
.187" (3/16")*
1/16"-3/32" 150 130-140 1/16"
.250" (1/4")* 3/32" 170 150-160 3/32"
.312" (5/16)*
3/32"-1/8" 200 170-180 3/32"
.375" (3/8)* 1/8" 220 220 1/8"
* May require beveling – depends on joint
Quick Set Up
1) Welding Mode in 2T for foot pedal or hand control.
2) Steel welding AC off – Aluminum Welding AC on
3) Slope down – 0.1 seconds
4) Pre Gas - 0.4 sec
5) Post Gas Flow – 8 Sec
6) Frequency – 150 Hz for aluminum. Not applicable for steel.
7) Balance – 65-75% for aluminum. Not applicable for steel.
8) Independent AC Amperage off (AC on light will not be
flashing) Not applicable for steel.
9) Ground clamp plugged into Positive receptacle
10) Tig Torch into Negative receptacle
11) Foot pedal or hand control plugged into 7 pin receptacle,
light flashing in lower right hand corner of amp display
indicating remote is connected
12) Pulse off
13) Gas Flow – 100% Argon set to 15 to 20 CFH while
the gas is flowing
17
*Amperage "rule of thumb": 1 amp per .001 inches.

18
Filler Rod for TIG Welding
HTP offers you high quality filler rods in affordable quantities.
All filler rod is packaged in 2 lb., air-tight plastic tubes to keep
your filler rod fresh and contaminant free.
In TIG welding, the filler rod is fed into the molten puddle
by hand. The choice of filler rod is extremely important as
the rod must correctly match the material and alloy you
will be welding. The thickness of the material to be welded
determines the diameter of the filler rod.
Here are some good rules of thumb to help you select the
correct filler metal:
1) 4043 is a good general filler metal for most aluminum
applications. Remember 2xxx and 7xxx series aluminum is
generally not recommended if the application requires
welding.
2) 5356 is used for 5xxx series aluminum and is generally
preferred if the finished piece will be anodized or needs to
be salt water corrosion resistant like in marine
applications.
3) ER70S-6 is generally used for mild steel welding.
4) ER70S-2 is highly recommended for welding 4130
chrome-moly tubing in many applications.
5) ER80S-D2 is recommended for welding 4130 chrome-moly
tubing if a higher strength, less ductile weld is required. If
your weld will be heat treated to obtain optimum strength,
then use a filler metal which matches the chemistry of your
tubing, which neither 70S-2 nor 80S-D2 wires do.
6) Generally speaking, use a 1/16" diameter filler rod for
applications where the material is 1/8" and less. Use a 3/32"
diameter rod for 1/8" and thicker.
The above Filler Rod is available from HTP in 2 lb. tubes
which are tightly sealed to prevent oxidation.
Filler Rod
Part # Material
4043-116-36-2 4043 Alloy Aluminum Wire 1/16" x 36"
4043-332-36-2 4043 Alloy Aluminum Wire 3/32" x 36"
5356-116-36-2 5356 Alloy Aluminum Wire 1/16" x 36"
5356-332-36-2 5356 Alloy Aluminum Wire 3/32" x 36"
308L-045-36-2 308L Stainless Steel Wire .035" x 36"
308L-116-36-2 308L Stainless Steel Wire 1/16" x 36"
70S6-116-36-2 ER70S-6 Steel Wire 1/16" x 36"
70S6-332-36-2 ER70S-6 Steel Wire 3/32" x 36"
70S2-116-36-2 ER70S-2 Steel Wire 1/16" x 36"
80SD2-116-36-2 ER80SD-2 Steel Wire 1/16" x 36"
Use 308 for most grades of stainless steel.
Use 309 or 312 for dissimilar metals or welding mild
steel to stainless steel.
7)
8)

19
Tungsten Diameter
Illus # Description 0.040" 1/16" 3/32" 1/8"
Standard Configuration
1 Alumina Nozzle 10N49 10N48 10N47 10N46
2 Collet Body 10N30 10N31 10N32 10N28
3 Collet 10N22 10N23 10N24 10N25
Gas Lens Configuration (optional)
1A Alumina Nozzle 54N17 54N16 54N15 54N14
2A Gas Lens Collet Body 45V24 45V25 45V26 45V27
3 Collet 10N22 10N23 10N24 10N25
Short Configuration (optional)
1B Alumina Nozzle 13N08 13N09 13N10 13N11
2B Collet Body 17CB20 17CB20 17CB20 17CB20
3B Collet 13N21 13N22 13N23 13N24
17 Series Air-Cooled TIG Torch Parts Breakdown
Following parts fit all tungsten diameters
4 18GC
3GHS
5 SR-17
5B SR-17F
6 98W18
7 300S
7A 300M
7B 300L
8
Cup Gasket (Std & Short)
Cup Gasket (Gas Lens)
Torch Head
Flexible Torch Head
O-Ring
Short Back Cap
Medium Back Cap
Long Back Cap
Handle H-100

20
Tungsten Diameter
Illus # Description 0.040" 1/16" 3/32" 1/8"
Gas Lens Configuration (optional)
1 Alumina Nozzle 53N59 53N60 53N61 53N61S
2 Gas Lens Collet Body 45V42 45V43 45V44 45V45
3 Collet 13N21 13N22 13N23 13N24
Standard Configuration
1A Alumina Nozzle 13N08 13N09 13N10 13N11
2 Collet Body 13N26 13N27 13N28 13N29
3 Collet 13N21 13N22 13N23 13N24
20 Series Water Cooled TIG Torch Parts Breakdown
Following parts fit all tungsten diameters
4 Cup Gasket 2GHS
5 Torch Head 20
5A Flexible Torch Head 20F
6 O-Ring 200R
7 Long Back Cap 200L
7A Medium Back Cap 200M
7B Short Back Cap 200S
8 Handle 20HR