INSTRUCTION MANUAL
Heliarc® 250 AC/DC
SQUARE WAVE POWER SOURCES
F-15-047-A
February, 1995
P/N 31310 - Heliarc 250 AC/DC w/power factor
P/N 31300 - Heliarc 250 AC/DC w/o power factor
NOTE: This manual is also suitable for use with L-TEC Heliarc 250 HF plus.
These INSTRUCTIONS are for experienced operators. If you are not fully familiar with the principles of operation and
safe practices for arc welding equipment, we urge you to read our booklet, "Precautions and Safe Practices for Arc
Welding, Cutting, and Gouging", Form 52-529. Do NOT permit untrained persons to install, operate, or maintain this
equipment. Do NOT attempt to install or operate this equipment until you have read and fully understand these
instructions. If you do not fully understand these instructions, contact your supplier for further information. Be sure
to read the Safety Precautions (Section 1) before installing or operating this equipment.
Be sure this information reaches the operator.
You can get extra copies through your supplier.
USER RESPONSIBILITY
This equipment will perform in conformity with the description thereof contained in this manual and
accompanying labels and/or inserts when installed, operated, maintained and repaired in accordance with the
instructions provided. This equipment must be checked periodically. Defective equipment should not be used.
Parts that are broken, missing, worn, distorted or contaminated should be replaced immediately. Should such
repair or replacement become necessary, the manufacturer recommends that a telephone or written request
for service advice be made to the Authorized Distributor from whom purchased.
This equipment or any of its parts should not be altered without the prior written approval of the manufacturer. The user of this equipment shall have the sole responsibility for any malfunction which results from
improper use, faulty maintenance, damage, improper repair or alteration by anyone other than the manufacturer or a service facility designated by the manufacturer.
2
SAFETY PRECAUTIONS
!
!
WARNING: These Safety Precautions are for
your protection. They summarize precaution-
!
performing any installation or operating procedures, be
sure to read and follow the safety precautions listed below
as well as all other manuals, material safety data sheets,
labels, etc. Failure to observe Safety Precautions can result
in injury or death.
burns. Training in the proper use of the processes and
equipment is essential to prevent accidents. Therefore:
1. Always wear safety glasses with side shields in any work
area, even if welding helmets, face shields, and goggles
are also required.
2. Use a face shield fitted with the correct filter and cover
plates to protect your eyes, face, neck, and ears from
sparks and rays of the arc when operating or observing
operations. Warn bystanders not to watch the arc and
not to expose themselves to the rays of the electric-arc
or hot metal.
3. Wear flameproof gauntlet type gloves, heavy long-sleeve
shirt, cuffless trousers, high-topped shoes, and a welding helmet or cap for hair protection, to protect against
arc rays and hot sparks or hot metal. A flameproof apron
may also be desirable as protection against radiated
heat and sparks.
4. Hot sparks or metal can lodge in rolled up sleeves,
trouser cuffs, or pockets. Sleeves and collars should be
kept buttoned, and open pockets eliminated from the
front of clothing
5. Protect other personnel from arc rays and hot sparks
with a suitable non-flammable partition or curtains.
6. Use goggles over safety glasses when chipping slag or
grinding. Chipped slag may be hot and can fly far.
Bystanders should also wear goggles over safety glasses.
1. Remove all combustible materials well away from the
work area or cover the materials with a protective nonflammable covering. Combustible materials include wood,
cloth, sawdust, liquid and gas fuels, solvents, paints and
coatings, paper, etc.
2. Hot sparks or hot metal can fall through cracks or
crevices in floors or wall openings and cause a hidden
smoldering fire or fires on the floor below. Make certain
that such openings are protected from hot sparks and
metal.“
3. Do not weld, cut or perform other hot work until the
workpiece has been completely cleaned so that there
are no substances on the workpiece which might produce flammable or toxic vapors. Do not do hot work on
closed containers. They may explode.
4. Have fire extinguishing equipment handy for instant use,
such as a garden hose, water pail, sand bucket, or
portable fire extinguisher. Be sure you are trained in its
use.
ary information from the references listed in
Additional Safety Information section. Before
PROTECT YOURSELF AND OTHERS
Some welding, cutting, and gouging processes are noisy and require ear protection. The arc, like the sun, emits ultraviolet (UV) and other radiation and can injure skin and eyes. Hot metal can cause
FIRES AND EXPLOSIONS -- Heat from
flames and arcs can start fires. Hot slag
or sparks can also cause fires and explosions. Therefore:
--
5. Do not use equipment beyond its ratings. For example,
overloaded welding cable can overheat and create a fire
hazard.
6. After completing operations, inspect the work area to
make certain there are no hot sparks or hot metal which
could cause a later fire. Use fire watchers when necessary.
7. For additional information, refer to NFPA Standard 51B,
"Fire Prevention in Use of Cutting and Welding Processes", available from the National Fire Protection Association, Batterymarch Park, Quincy, MA 02269.
ELECTRICAL SHOCK -- Contact with
live electrical parts and ground can
cause severe injury or death. DO NOT
use AC welding current in damp areas,
if movement is confined, or if there is
danger of falling.
1. Be sure the power source frame (chassis) is connected
to the ground system of the input power.
2. Connect the workpiece to a good electrical ground.
3. Connect the work cable to the workpiece. A poor or
missing connection can expose you or others to a fatal
shock.
4. Use well-maintained equipment. Replace worn or damaged cables.
5. Keep everything dry, including clothing, work area, cables,
torch/electrode holder, and power source.
6. Make sure that all parts of your body are insulated from
work and from ground.
7. Do not stand directly on metal or the earth while working
in tight quarters or a damp area; stand on dry boards or
an insulating platform and wear rubber-soled shoes.
8. Put on dry, hole-free gloves before turning on the power.
9. Turn off the power before removing your gloves.
10. Refer to ANSI/ASC Standard Z49.1 (listed on next page)
for specific grounding recommendations. Do not mistake the work lead for a ground cable.
ELECTRIC AND MAGNETIC FIELDS —
May be dangerous. Electric current flowing through any conductor causes localized Electric and Magnetic Fields (EMF).
Welding and cutting current creates EMF
around welding cables and welding machines. Therefore:
1. Welders having pacemakers should consult their physician before welding. EMF may interfere with some pacemakers.
2. Exposure to EMF may have other health effects which are
unknown.
3. Welders should use the following procedures to minimize
exposure to EMF:
A. Route the electrode and work cables together. Secure
them with tape when possible.
B. Never coil the torch or work cable around your body.
C. Do not place your body between the torch and work
cables. Route cables on the same side of your body.
D. Connect the work cable to the workpiece as close as
possible to the area being welded.
E. Keep welding power source and cables as far away
from your body as possible.
2
11/95
FUMES AND GASES -- Fumes and gases,
can cause discomfort or harm, particularly in confined spaces. Do not breathe
fumes and gases. Shielding gases can
cause asphyxiation. Therefore:
1. Always provide adequate ventilation in the work area by
natural or mechanical means. Do not weld, cut, or gouge
on materials such as galvanized steel, stainless steel,
copper, zinc, lead, beryllium, or cadmium unless positive mechanical ventilation is provided. Do not breathe
fumes from these materials.
2. Do not operate near degreasing and spraying operations. The heat or arc rays can react with chlorinated
hydrocarbon vapors to form phosgene, a highly toxic
gas, and other irritant gases.
3. If you develop momentary eye, nose, or throat irritation
while operating, this is an indication that ventilation is not
adequate. Stop work and take necessary steps to improve ventilation in the work area. Do not continue to
operate if physical discomfort persists.
4. Refer to ANSI/ASC Standard Z49.1 (see listing below)
for specific ventilation recommendations.
CYLINDER HANDLING -- Cylinders, if
mishandled, can rupture and violently
release gas. Sudden rupture of cylinder,
valve, or relief device can injure or kill.
Therefore:
1. Use the proper gas for the process and use the proper
pressure reducing regulator designed to operate from
the compressed gas cylinder. Do not use adaptors.
Maintain hoses and fittings in good condition. Follow
manufacturer's operating instructions for mounting regulator to a compressed gas cylinder.
2. Always secure cylinders in an upright position by chain
or strap to suitable hand trucks, undercarriages, benches,
walls, post, or racks. Never secure cylinders to work
tables or fixtures where they may become part of an
electrical circuit.
3. When not in use, keep cylinder valves closed. Have
valve protection cap in place if regulator is not connected. Secure and move cylinders by using suitable
hand trucks. Avoid rough handling of cylinders.
4. Locate cylinders away from heat, sparks, and flames.
Never strike an arc on a cylinder.
5. For additional information, refer to CGA Standard P-1,
"Precautions for Safe Handling of Compressed Gases in
Cylinders", which is available from Compressed Gas
Association, 1235 Jefferson Davis Highway, Arlington,
VA 22202.
EQUIPMENT MAINTENANCE -- Faulty or improperly maintained equipment can cause
!
injury or death. Therefore:
1. Always have qualified personnel perform the installation, troubleshooting, and maintenance work. Do not
perform any electrical work unless you are qualified to
perform such work.
2. Before performing any maintenance work inside a power
source, disconnect the power source from the incoming
electrical power.
3. Maintain cables, grounding wire, connections, power cord,
and power supply in safe working order. Do not operate
any equipment in faulty condition.
4. Do not abuse any equipment or accessories. Keep
equipment away from heat sources such as furnaces, wet
conditions such as water puddles, oil or grease, corrosive
atmospheres and inclement weather.
5. Keep all safety devices and cabinet covers in position and
in good repair.
6. Use equipment only for its intended purpose. Do not
modify it in any manner.
ADDITIONAL SAFETY INFORMATION -- For more information on safe practices for electric arc welding and
cutting equipment, ask your supplier for a
copy of "Precautions and Safe Practices for
!
The following publications, which are available from the
American Welding Society, 550 N.W. LeJuene Road, Miami,
FL 33126, are recommended to you:
1. ANSI/ASC Z49.1 - "Safety in Welding and Cutting"
2. AWS C5.1 - "Recommended Practices for Plasma Arc
Welding"
3. AWS C5.2 - "Recommended Practices for Plasma Arc
Cutting"
4. AWS C5.3 - "Recommended Practices for Air Carbon Arc
Gouging and Cutting"
5. AWS C5.5 - "Recommended Practices for Gas Tungsten
Arc Welding“
6. AWS C5.6 - "Recommended Practices for Gas Metal Arc
Welding"“
7. AWS SP - "Safe Practices" - Reprint, Welding Handbook.
8. ANSI/AWS F4.1, "Recommended Safe Practices for Welding and Cutting of Containers That Have Held Hazardous
Substances."
The following definitions apply to DANGER, WARNING,
CAUTION found throughout this manual:
!
WARNING
!
CAUTION
!
Arc Welding, Cutting and Gouging", Form
52-529.
This symbol appearing throughout this manual
means Attention! Be Alert! Your safety is
!
involved.
Used to call attention to immediate haz-
DANGER
ards which, if not avoided, will result in
immediate, serious personal injury or
loss of life.
Used to call attention to potential hazards which could result in personal injury
or loss of life.
Used to call attention to hazards which
could result in minor personal injury.
3
SECTION 1 DESCRIPTION
1.1 Introduction
The Heliarc 250 AC/DC welding power sources are constant current AC/DC welding power sources for high
quality tig and stick welding in both the AC and DC mode.
The unique characteristics of the magnetic and solid state
circuits provide excellent arc conditions for all tig welding
as well as high alloy stick electrodes. The non-saturating
current limiting reactor and electronic feedback control
prohibits high current surges inherent with saturable
reactors or solid state SCR control alone, therefore reducing spatter on stick electrodes as well as tungsten
spitting when tig welding. The electronic firing circuit
utilizes a voltage compensating circuit which compensates for line voltage variations of +/-10 percent.
Through its unique design, the Heliarc 250 AC/DC combines all of the latest state-of-the art magnetic and solid
state concepts to provide the wide range volt-ampere
curve characteristics needed for a constant current AC/
DC power source - see Figure 1-1. Refer to Table 1-1 for
technical specifications.
Table 1-1. Specifications
total of 4 minutes and shut off for a total of 6 minutes in a
10-minute period. However, if the welding current is
decreased, the duty cycle can be increased. Conversely,
if the welding current is increased, the duty cycle must be
decreased. Figure 1-2 enables the operator to determine
the safe output of the power source at various duty cycles.
Note that the duty cycle of the unit without p.f. is approximately 50% less (25% less on unit with p.f.) when
Balance Control is in the "max. penetration" position.
Rated Output @
40% Duty Cycle
Open Circuit Voltage 79 Volts AC/72 Volts DC
Output
Current
Range in
Amperes
Input Voltage AC 208/230/460 V, 1P, 60 Hz
Input Current @
Rated Load in
Amperes
Power Factor @
Rated Load
Auxiliary Power Output 115 V AC, 15 Amp, 60 Hz
Dimensions: Width
Weight 380 lbs 171 kg
* P.F.C. indicates with or without power factor correction
¹ The input currents listed are for balance control in the "max. clean" (0) position.
When balance control is set in the "max. penetration" (10) position, input current
will increase approximately 40%.
¹
Welding Current
Low Range
High Range
without P.F.C.*
with P.F.C.*
without P.F.C.*
with P.F.C.*
Depth
Height
250 Amps @ 30 Volts
AC/DC, Tig/Stick
AC/DC
5 to 60 Amps
15 to 320 Amps
(20 to 320 Amps*)
208 V 230 V 460 V
107 96 48
83 74 37
Approx. 52%
Approx. 76%
16 in. 406 mm
30 in. 762 mm
22 in. 559 mm
(295 lbs 179 kg*)
Figure 1-1. Volt-Ampere Curves
1.2 Duty Cycle
Duty cycle is defined as the ratio of load time to the total
time. Standard current ratings are based on a 10-minute
cycle. This machine is rated at 40 percent duty cycle
which means the rated load (250 amps.) is applied for a
1-1
Figure 1-2. Duty Cycle Chart
5
SECTION 2 INSTALLATION
2.1 Installation
Proper installation can contribute materially to the satisfactory and trouble-free operation of the power source. It
is suggested that each step in this section be studied
carefully and followed as closely as possible.
A. UNPACKING AND PLACEMENT
1. Immediately upon receipt of the power source, it
should be inspected for damage which may have
occurred in transit. Notify the carrier of any defects
or damage at once.
2. After removing the power source from the shipping
container, check the container for any loose parts.
Remove all packing materials.
3. Check air passages at front, bottom, and rear of
cabinet for any packing materials that may obstruct
air flow through the power source.
4. If the machine is not to be installed immediately,
store it in a clean, dry, well-ventilated area.
Although designed with line voltage compensation, it is
suggested the unit be operated on a separate circuit to
assure that the performance of the machine is not impaired due to an overloaded circuit.
ELECTRIC SHOCK CAN KILL! Do not touch electrically live parts. Be sure that all power is off by
opening the line (wall) disconnect switch when primary electrical connections are made to the power
source. To be doubly safe, check your input leads
with a voltmeter to make sure that all power is OFF.
1. A line (wall) disconnect switch, with fuses or circuit
breakers, should be provided at the main power
panel (see Fig. 2-1). The primary power input must
have three insulated copper conductors (two power
leads and one ground wire). The wires may be
heavy rubber-covered cable, or may be run in a
solid or flexible conduit. Refer to the following table
for recommended input conductors and line fuse
sizes. Do not connect the input conductors
until step 3.
5. The location of the welding machine should be
carefully selected to ensure satisfactory and dependable service. Using the lifting eyebolt, or a
fork-lift truck, place the power source in the desired
location. Choose a location relatively close to a
properly fused supply of electrical power.
6. The machine's components are maintained at
proper operating temperature by forced air which is
drawn through the cabinet by the fan unit on the rear
panel. The power source is designed to operate up
to a 40 °C (104 °F) ambient temperature. For this
reason, locate the machine in an open area where
air can circulate freely at front, bottom, and rear
openings. Leave at least 2 feet of clearance
between the rear of the power source and wall or
other obstruction.
IMPORTANT: Do not use filters on this unit. Output
ratings are designed and based on an
unobstructed supply of "clean" cooling
air drawn over its internal components. If
cooling air is dirty (e.g., laden with conductive dust), the interior should be
cleaned using low pressure air (see Maintenance).
B. PRIMARY (INPUT) ELECTRICAL CONNECTIONS
Table 2-1. Recommended Sizes for Input
Conductors and Line Fuses
Input Requirements Input & Gnd.
Conductor*
Volts Amps.
CU/AWG
Time-Delay
Fuse Size
Amps.
Part No. 1341-0355/0356/0357/0358
208 (200)
230
460
107
96
48
No. 2
No. 2
No. 6
150
150
70
Part No. 1341-0366/0367
230
460
575
96
48
38
No. 2
No. 6
No. 8
150
70
60
Part No. 1341-0368
Part No. 1341-0369
220
380
415
440
* Sized per National Electric Code for 75°C rated conductors @
30°C ambient. Not more than three conductors in raceway or
cable. Local codes should be followed if they specify sizes other
than those listed above.
78
45
41
39
3
6
8
8
125
70
60
60
This welding power source is a single-phase unit and
must be connected to a single-phase power supply.
6
2-1
SECTION 2 INSTALLATION
2. For access to input terminal board, remove the
screws which secure the right side access panel of
the power source. The input terminal board, Figure
2-2, is clearly marked to show the available primary
voltage connections which may be used. Set the
voltage links, on this board, to match your actual
incoming voltage. As shipped from the factory, the
input terminal board voltage links are set up to
match the highest available voltage.
15 AMP/115 VAC DUPLEX & CIRCUIT
BREAKER (on Rear Panel)
ELECTRODE
SERVICE
HOSE
TORCH
CONNECTION
3. Thread the input conductor cables from the wall
disconnect switch through the (strain relief) hole in
the rear panel (see Fig. 2-1). Secure the cables with
the strain relief coupling provided and then connect
conductors to terminals L1 and L2 (on the input
terminal board) using UL listed pressure wire connectors. Connect the ground wire to the grounding
stud provided on the chassis base near the input
terminal board.
Customer's Fused Line
Disconnect Switch
Customer's Single
OPT. WATER
KIT P/N
30459
INPUT TERMINAL BOARD
CHASSIS
GROUND
CONNECTION
Phase Line Voltage
Connections (including
"Ground")
Customer's
Shutoff Valve
WATER COUPLING
(Hose, 40V76 - 12-1/2 -Ft.)
DETAIL A
TYPICAL ADAPTOR
MTG. ORIENTATION
TIG TORCH
(Air Cooled)
STICK
TIG TORCH
(Water
Cooled)
WORK
Connect Work
To Approved
Earth Ground
(By Customer)
ADAPTOR
(DET. A)
ADAPTOR
(DET. A)
FOOT CONTROL
FC-4 - 679662
-or-
TC-1A TORCH
CONTROL - 34718
Alternate
Connection
TORCH GAS
(Hose, 2075675 - 30-in.)
POWER CABLE/CONNECTIONS
REMOTE CURRENT CONTROL
REMOTE CONTACTOR CONTROL
WORK CABLE
TORCH WATER
WATER DRAIN
(Hose, 40V76 - 12-1/2-Ft.)
CONNECTOR - 11N16
REMOTE CURRENT HAND
CONTROL - 674209
REMOTE CONTACTOR TORCH
SWITCH - 674038
CONNECTOR - 11N16
GAS SUPPLY
(Hose, 40V77 - 12-1/2-Ft.)
WATER COUPLING - 11N18
Figure 2-1. Interconnection Diagram
2-2
7
SECTION 2 INSTALLATION
The proper operation of the welding machine depends to
a great extent on the use of output cables that are
insulated copper, adequately sized, in good condition,
and properly connected to the machine using UL listed
Customer's
Input Cable
Connection
pressure wire connectors. It is recommended that the
output cables be kept as short as possible (this is
particularly important for tig applications using
ACHF), and be of adequate current carrying capacity.
The resistance of the output cables and connections
causes a voltage drop which is added to the voltage of the
arc. Excessive cable resistance may result in overloading as well as reducing the maximum current output of
which the power source is capable. The welding output
terminals are located on the front panel. The following
table will prove useful for selecting the recommended
output cable size.
* DOUBLE LINKS PROVIDED
Fig. 2.2 - Input Terminal Board
It is of the utmost importance that the chassis be
connected to an approved electrical ground to prevent accidental shocking. Take care not to connect
the ground wire to any of the primary leads.
4. Recheck all connections to make sure they are
tight, well insulated, and that the proper connection
has been made.
C. EXTERNAL PRIMARY/SECONDARY CONNEC-
TIONS
Verify that all electrical connections comply with
local electrical codes and especially with requirements established in booklet ADI-5054 "High Frequency Stabilized Arc Welding Equipment", which is
packed with this power source.
Refer to Interconnection Diagram, Figure 2-1, for typical
primary input, secondary output, process gas and water,
and torch connections that are required for this unit's
welding application.
Welding
Current
200
250
* Total cable length includes work and electrode cables. Cable size
is based on direct current, insulated copper conductors, 40% duty
cycle, and a voltage drop of 4 or less volts. The welding cable
insulation must have a voltage rating that is high enough to
withstand the open circuit voltage of the machine.
Total Length (Feet) of Cable in Weld Circuit*
50 100 150 200 250
2
1
2
1
1
1/0
1
1/0
1/0
1/0
D. ACCESSORIES
1. FC-4 Foot Current and Contactor Control, P/N
679662. This device provides the operator with
remote control of current and contactor operation
at the welding station. Interconnection of these
functions to the main unit is provided by a mating
25-foot cable/plug assembly. By depressing the
foot pedal, the weld-start sequence circuit will energize, and the welding current will increase or
decrease within the range preset on the power
source Current Control potentiometer.
2. TC-1A Torch Current and Contactor Control, P/
N 34718 (25-ft lg). This remote fingertip control is
designed to be taped to any Tig torch handle and to
provide the operator with complete contactor control and variable control of the welding current. By
simply rotating the knob clockwise (off of zero), the
integral switch will energize the contactor. Further
rotation (clockwise) will increase the output current
up to the limit preset on the power source main
control.
Before making any connections to the power source's
output receptacles, make sure that all primary input
power to the machine is deenergized (off) at the
customer's disconnect switch.
8
3. Torch Switch Assembly, P/N 674038. This device is designed to be attached to any tig welding
torch, and provides the operator with remote
2-3
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