Lincoln Electric IM556 User Manual

AC-235

RETURN TO MAIN MENU

WELDING POWER SOURCE

by

IM556

May, 2004

Contents Page

Safety Precautions ...............................................................................................2

Installation and Operating Instructions

for AC-235 ...................................................................................................7

Includes safety, installation, operating instructions
and parts lists.

Learning to Weld ...............................................................................................11

Using the Carbon Arc Torch..............................................................................18

Includes for heating metal, welding aluminum or
brazing with an arc torch.

Selecting Electrodes ..........................................................................................23

Brief descriptions of the types and operating
data for all Lincoln electrodes.

Welding Books and Teaching Aids ...................................................................25

Copyright © 2004 Lincoln Global Inc.

• World's Leader in Welding and Cutting Products •

• Sales and Service through Subsidiaries and Distributors Worldwide •

Cleveland, Ohio 44117-1199 U.S.A. TEL: [phone] FAX: [phone] WEB SITE: www.lincolnelectric.com

SAFETY

WARNING

ARC WELDING can be hazardous.

PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDREN
AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.

Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you pur­chase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1” from the American Welding Society, P.O. Box 351040,
Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety” booklet E205 is available from the
Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.

BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE PER­FORMED ONLY BY QUALIFIED INDIVIDUALS.

ELECTRIC SHOCK can kill.

1.a. 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.

1.b. 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.

In addition to the normal safety precautions, if welding
must be performed under electrically hazardous
conditions (in damp locations or while wearing wet
clothing; on metal structures such as floors, gratings or
scaffolds; when in cramped positions such as sitting,
kneeling or Iying, if there is a high risk of unavoidable or
accidental contact with the workpiece or ground) use
the following equipment:

• Semiautomatic DC Constant Voltage (Wire) Welder.

• DC Manual (Stick) Welder.

• AC Welder with Reduced Voltage Control.

1.c. In semiautomatic or automatic wire welding, the electrode,
electrode reel, welding head, nozzle or semiautomatic
welding gun are also electrically “hot”.

1.d. 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.

1.e. Ground the work or metal to be welded to a good electrical
(earth) ground.

1.f.

Maintain the electrode holder, work clamp, welding cable and
welding machine in good, safe operating condition. Replace
damaged insulation.

1.g. Never dip the electrode in water for cooling.

1.h. 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.

1.i. When working above floor level, use a safety belt to protect
yourself from a fall should you get a shock.

1.j. Also see Items 4.c. and 6.

2.b. Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
the arc rays.

2.c. 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.

fumes and gases away from the breathing zone. When

welding with electrodes which require special
ventilation such as stainless or hard facing (see
instructions on container or MSDS) 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 (TLV)
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.

3.b.

Do not weld in locations near chlorinated hydrocarbon
coming from degreasing, cleaning or spraying operations.
The heat and rays of the arc can react with solvent vapors
form phosgene, a highly toxic gas, and other irritating
products.

3.c. 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.

3.d. Read and understand the manufacturer’s instructions for this
equipment and the consumables to be used, including the
material safety data sheet (MSDS) and follow your
employer’s safety practices. MSDS forms are available from
your welding distributor or from the manufacturer.

ARC RAYS can burn.

2.a. Use a shield with the proper filter and cover
plates to protect your eyes from sparks and
the rays of the arc when welding or observing
open arc welding. Headshield and filter lens
should conform to ANSI Z87. I standards.

FUMES AND GASES
can be dangerous.

3.a. 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

vapors

to

Apr. ‘93

3.e. Also see item 7b.

– 2 –

SAFETY

WELDING SPARKS can
cause fire or explosion.

4.a.

Remove fire hazards from the welding area.

If this is not possible, cover them to prevent

the welding sparks from starting a fire.

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.

4.b. Where compressed gases are to be used at the job site,
special precautions should be used to prevent hazardous
situations. Refer to “Safety in Welding and Cutting” (ANSI
Standard Z49.1) and the operating information for the
equipment being used.

4.c. 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.

4.d. 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 an explosion even
been “cleaned”. For information, purchase “Recommended
Safe Practices for the
Containers and Piping That Have Held Hazardous
Substances”, AWS F4.1 from the American Welding Society

(see address above).

4.e. Vent hollow castings or containers before heating, cutting or
welding. They may explode.

Sparks and spatter are thrown from the welding arc. Wear oil

4.f.
free protective garments such as leather gloves, heavy shirt,
cuffless 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.

4.g. 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.

4.h. Also see item 7c.

Remember that welding sparks and hot

though

they have

Preparation

for Welding and Cutting of

CYLINDER may explode
if damaged.

5.a. 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.

5.b. Always keep cylinders in an upright position securely
chained to an undercarriage or fixed support.

5.c. 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.

5.d. Never allow the electrode, electrode holder or any other
electrically “hot” parts to touch a cylinder.

5.e. Keep your head and face away from the cylinder valve outlet
when opening the cylinder valve.

5.f. Valve protection caps should always be in place and hand
tight except when the cylinder is in use or connected for
use.

5.g. Read and follow the instructions on compressed gas
cylinders, associated equipment, and CGA publication P-l,
“Precautions for Safe Handling of Compressed Gases in
Cylinders,” available from the Compressed Gas Association
1235 Jefferson Davis Highway, Arlington, VA 22202.

FOR ELECTRICALLY
powered equipment.

6.a. Turn off input power using the disconnect
switch at the fuse box before working on
the equipment.

6.b. Install equipment in accordance with the U.S. National
Electrical Code, all local codes and the manufacturer’s
recommendations.

6.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.

– 3 –

Mar. ‘93

SAFETY

FOR ENGINE
powered equipment.

7.a. Turn the engine off before troubleshooting and maintenance
work unless the maintenance work requires it to be running.

____________________________________________________

7.b. Operate engines in open, well-ventilated
areas or vent the engine exhaust fumes

outdoors.

____________________________________________________

7.c. Do not add 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.

____________________________________________________

7.d. 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.

ELECTRIC AND MAGNETIC
FIELDS
may be dangerous

8.a. Electric current flowing through any conductor causes
localized Electric and Magnetic Fields (EMF). Welding
current creates EMF fields around welding cables and
welding machines

8.b. EMF fields may interfere with some pacemakers, and
welders having a pacemaker should consult their physician
before welding.

8.c. Exposure to EMF fields in welding may have other health
effects which are now not known.

8d. All welders should use the following procedures in order to

minimize exposure to EMF fields from the welding circuit:

8.d.1.

Route the electrode and work cables together - Secure
them with tape when possible.

8.d.2. Never coil the electrode lead around your body.

8.d.3. Do not place your body between the electrode and

work cables. If the electrode cable is on your right
side, the work cable should also be on your right side.

8.d.4. Connect the work cable to the workpiece as close as

possible to the area being welded.

8.d.5. Do not work next to welding power source.

____________________________________________________

7.e. In some cases it may be necessary to remove safety
guards to perform required maintenance. Remove
guards only when necessary and replace them when the
maintenance requiring their removal is complete.
Always use the greatest care when working near moving
parts.

7.f. 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.

7.g. To prevent accidentally starting gasoline engines while
turning the engine or welding generator during maintenance
work, disconnect the spark plug wires, distributor cap or
magneto wire as appropriate.

___________________________________________________

7.h. To avoid scalding, do not remove the
radiator pressure cap when the engine is
hot.

– 4 –

Mar. ‘93

SAFETY

PRÉCAUTIONS DE SÛRETÉ

Pour votre propre protection lire et observer toutes les instructions

et les précautions de sûreté specifiques qui parraissent dans ce

manuel aussi bien que les précautions de sûreté générales suiv-

antes:

Sûreté Pour Soudage A L’Arc

1. Protegez-vous contre la secousse électrique:

a. Les circuits à l’électrode et à la piéce sont sous tension

quand la machine à souder est en marche. Eviter toujours

tout contact entre les parties sous tension et la peau nue ou

les vétements mouillés. Porter des gants secs et sans trous

pour isoler les mains.

b. Faire trés attention de bien s’isoler de la masse quand on

soude dans des endroits humides, ou sur un plancher met-

allique ou des grilles metalliques, principalement dans

les positions assis ou couché pour lesquelles une grande

partie du corps peut être en contact avec la masse.

c. Maintenir le porte-électrode, la pince de masse, le câble de

soudage et la machine à souder en bon et sûr état defonc-

tionnement.

d.Ne jamais plonger le porte-électrode dans l’eau pour le

refroidir.

e. Ne jamais toucher simultanément les parties sous tension

des porte-électrodes connectés à deux machines à souder

parce que la tension entre les deux pinces peut être le total

de la tension à vide des deux machines.

f. Si on utilise la machine à souder comme une source de

courant pour soudage semi-automatique, ces precautions

pour le porte-électrode s’applicuent aussi au pistolet de

soudage.

zones où l’on pique le laitier.

6. Eloigner les matériaux inflammables ou les recouvrir afin de

prévenir tout risque d’incendie dû aux étincelles.

7. Quand on ne soude pas, poser la pince à une endroit isolé de

la masse. Un court-circuit accidental peut provoquer un échauf-

fement et un risque d’incendie.

8. S’assurer que la masse est connectée le plus prés possible de

la zone de travail qu’il est pratique de le faire. Si on place la

masse sur la charpente de la construction ou d’autres endroits

éloignés de la zone de travail, on augmente le risque de voir

passer le courant de soudage par les chaines de levage, câbles

de grue, ou autres circuits. Cela peut provoquer des risques

d’incendie ou d’echauffement des chaines et des câbles jusqu’à

ce qu’ils se rompent.

9. Assurer une ventilation suffisante dans la zone de soudage.

Ceci est particuliérement important pour le soudage de tôles

galvanisées plombées, ou cadmiées ou tout autre métal qui pro-

duit des fumeés toxiques.

10. Ne pas souder en présence de vapeurs de chlore provenant

d’opérations de dégraissage, nettoyage ou pistolage. La

chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs

du solvant pour produire du phosgéne (gas fortement toxique)

ou autres produits irritants.

11. Pour obtenir de plus amples renseignements sur la sûreté, voir

le code “Code for safety in welding and cutting” CSA Standard

W 117.2-1974.

2. Dans le cas de travail au dessus du niveau du sol, se protéger

contre les chutes dans le cas ou on recoit un choc. Ne jamais

enrouler le câble-électrode autour de n’importe quelle partie du

corps.

3. Un coup d’arc peut être plus sévère qu’un coup de soliel, donc:

a. Utiliser un bon masque avec un verre filtrant approprié ainsi

qu’un verre blanc afin de se protéger les yeux du rayon-

nement de l’arc et des projections quand on soude ou quand

on regarde l’arc.

b. Porter des vêtements convenables afin de protéger la peau

de soudeur et des aides contre le rayonnement de l‘arc.

c. Protéger l’autre personnel travaillant à proximité au soudage

à l’aide d’écrans appropriés et non-inflammables.

4. Des gouttes de laitier en fusion sont émises de l’arc de

soudage. Se protéger avec des vêtements de protection libres

de l’huile, tels que les gants en cuir, chemise épaisse, pantalons

sans revers, et chaussures montantes.

5. Toujours porter des lunettes de sécurité dans la zone de

soudage. Utiliser des lunettes avec écrans lateraux dans les

PRÉCAUTIONS DE SÛRETÉ POUR
LES MACHINES À SOUDER À
TRANSFORMATEUR ET À
REDRESSEUR

1. Relier à la terre le chassis du poste conformement au code de

l’électricité et aux recommendations du fabricant. Le dispositif

de montage ou la piece à souder doit être branché à une bonne

mise à la terre.

2. Autant que possible, I’installation et l’entretien du poste seront

effectués par un électricien qualifié.

3. Avant de faires des travaux à l’interieur de poste, la debrancher

à l’interrupteur à la boite de fusibles.

4. Garder tous les couvercles et dispositifs de sûreté à leur place.

– 5 –

Mar. ‘93

for selecting a QUALITY product by Lincoln Electric. We want you

Thank You

to take pride in operating this Lincoln Electric Company product •••
as much pride as we have in bringing this product to you!

Please Examine Carton and Equipment For Damage Immediately

When this equipment is shipped, title passes to the purchaser upon receipt by the carrier. Consequently, Claims
for material damaged in shipment must be made by the purchaser against the transportation company at the time
the shipment is received.

Please record your equipment identification information below for future reference. This information can be found
on your machine nameplate.

Product _________________________________________________________________________________

Model Number ___________________________________________________________________________

Code Number or Date Code_________________________________________________________________

Serial Number____________________________________________________________________________

Date Purchased___________________________________________________________________________

Where Purchased_________________________________________________________________________

Whenever you request replacement parts or information on this equipment, always supply the information you
have recorded above. The code number is especially important when identifying the correct replacement parts.

On-Line Product Registration

- Register your machine with Lincoln Electric either via fax or over the Internet.

• For faxing: Complete the form on the back of the warranty statement included in the literature packet
accompanying this machine and fax the form per the instructions printed on it.

• For On-Line Registration: Go to our

“Product Registration”. Please complete the form and submit your registration.

Read this Operators 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.
The level of seriousness to be applied to each is explained below:

WEB SITE at www.lincolnelectric.com. Choose “Quick Links” and then

WARNING

This statement appears where the information must be followed exactly to avoid serious personal injury or
loss of life.

CAUTION

This statement appears where the information must be followed to avoid minor personal injury or damage to
this equipment.

– 6 –

OPERATING INSTRUCTIONS

WARNING

•Have an electrician install and service this equipment.

•Turn the input power off at the fuse box before work­ing on equipment.

•Do not touch electrically hot parts.

Input Power and Grounding Connections

Before starting the installation, check with the power com­pany to be sure your power supply is adequate for the volt­age, amperes, phase and frequency specified on the welder
nameplate. Also, be sure the planned installation will meet
the United States National Electrical Code and local code
requirements. This welder may be operated from a single
phase line or from one phase of a two or three phase line.

CONNECT TO A SYSTEM GROUNDING
WIRE. SEE THE UNITED STATES
NATIONAL ELECTRICAL CODE
AND/OR LOCAL CODES FOR OTHER
DETAILS AND MEANS FOR PROPER
GROUNDING.

CONNECT TO HOT WIRES OF
A THREE-WIRE, SINGLE
PHASE SYSTEM OR TO ONE

}

PHASE OF A TWO OR THREE
PHASE SYSTEM.

Attaching Electrode Cable to Holder

WARNING

All models designed to operate on less than 250 volt input
lines are shipped with the input cable connected to the
welder.

Place the welder so there is free circulation of air in through
the louvers in the back and sides of the case and out of the
bottom on all four sides. Mount a NEMA Type 6-50R
receptacle in a suitable location. Be sure it can be reached
by the plug on the input cable attached to the welder.

WARNING

These installation instructions apply to the input wiring
and overload protection installed to supply one AC-235
and comply with the United States National Electrical
Code as it applies to electric welders. Other equipment
should not be connected to this supply without consult­ing the input power requirements for that equipment,
the United States National Electrical Code, and all local
codes.

Using the following instructions, have a qualified electri­cian connect this receptacle (NEMA 6-50R Type) to the
power lines at the fuse box. Three #10 or larger copper
wires are required if conduit is used. For long cable runs
over 100', #8 or larger wire in conduit will be needed to
prevent excessive voltage drops. Fuse the two hot lines
with 50 ampere super lag type fuses as shown in the fol­lowing diagram. The center contact in the receptacle is for
the grounding connection. A green wire in the input cable
connects this contact to the frame of the welder. This
insures proper grounding of the welder frame when the
welder plug is inserted into the receptacle. If a separate dis­connect switch is used, it should have two poles for the two
hot lines and both should be fused for 50 amperes.

Before attaching the electrode cable to the electrode
holder or the work cable to clamp, be certain the welder
is turned off or the input power is disconnected.

1. Loosen locking screw and slide handle off holder. Place
handle over electrode cable.

2. Remove insulation from electrode cable 1” ± 1/16”
(25.4mm ± 1.6mm) from end.

3. Back out cable connecting screw until end is flush with
inside surface of jaw body.

4. Remove cable connecting clamp from holder jaws. Place
clamp over bare end of electrode cable and insert into
holder with clamp centered against connecting screw.

5. Tighten cable connecting screw securely against clamp.

– 7 –

6. Slide handle into position and secure by turning the lock­ing screw in until it is tight. The threaded end of the
screw will then pass against the inside of the handle and
the head of the screw will be completely inside the han­dle.

Important Safety Note: Make sure insulation is secure and
that screws are tight and cannot be touched. If screw can
be touched, DO NOT USE HOLDER, contact your dis­tributor.

Attaching Work Cable to Clamp

Insert work cable through strain relief hole in work clamp
and fasten securely with bolt and nut provided.

Duty Cycle

The AC-235 is rated for 20% duty cycle on all switch posi­tions except maximum (235 amps). At 235 amps the duty
cycle is 18%. A 20% duty cycle means that the arc can be
drawn for 2 minutes out of each ten minute period. An 18%
duty cycle means that the arc can be drawn for 1.8 minutes
out of each ten minute period. If the welding time is longer
than this for several successive ten minute periods, the
windings may overheat and be damaged. Be sure to leave
the unit “on” for each 10 minute period to let the fan motor
run for adequate cooling. Overheating reduces welder life.

Electrode Selection Guide

See Chart on Welder and at the end of this manual

Arc Torch (Optional Accessory)

The arc torch (see page 18) is especially suited for use on
these welders for brazing, welding non-ferrous metals and
preheating before bending and forming.

Electrode and Work Cable Replacement

Substitution of cables with larger sizes requiring connec­tions to be made internally is not recommended.
Connections for additional lengths or larger sizes should be
properly made externally. Lincoln Electric QD (Quick
Disconnect) connectors are available for this purpose.

If either cable requires replacement for other reasons, they
should be replaced with the appropriate Lincoln parts—
and only by qualified personnel.

Welding Current Selection

Each position on the current selector switch is marked with
the output amperes for that setting. Turn the switch to the
current required for each application.

There is a slight amount of play in each switch position. It
is good practice to move the switch back and forth once
within this play after switching to a new position. This wip­ing action keeps the contacts free from dirt and oxides.

MAINTENANCE

Routine preventative maintenance is not required. See your
local Lincoln Electric Authorized Field Service Shop for
necessary repairs.

CAUTION

Do not turn the selector switch while welding as this will
damage the contacts.

– 8 –

NOTES

–9 –