Lincoln arc welding and cutting
equipment is designed and built
with safety in mind. However, your
overall safety can be increased by
proper installation ... and thoughtful operation on your part. DO
NOT INSTALL, OPERATE OR
REPAIR THIS EQUIPMENT
WITHOUT READING THIS
MANUAL AND THE SAFETY
PRECAUTIONS CONTAINED
THROUGHOUT. And, most
importantly, think before you act
and be careful.
July, 1996
View Safety InfoView Safety InfoView Safety InfoView Safety Info
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World's Leader in Welding and Cutting ProductsPremier Manufacturer of Industrial Motors
SERVICE MANUAL
Sales and Service through Subsidiaries and Distributors Worldwide
Diesel engine exhaust and some of its constituents
are known to the State of California to cause cancer, birth defects, and other reproductive harm.
The Above For Diesel Engines
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.
The engine exhaust from this product contains
chemicals known to the State of California to cause
cancer, birth defects, or other reproductive harm.
The Above For Gasoline Engines
FOR ENGINE
powered equipment.
1.a. Turn the engine off before troubleshooting and maintenance
work unless the maintenance work requires it to be running.
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.
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.
1.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.
1.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.
1.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.
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1.h. To avoid scalding, do not remove the
radiator pressure cap when the engine is
hot.
ELECTRIC AND
MAGNETIC FIELDS
may be dangerous
2.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
2.b. EMF fields may interfere with some pacemakers, and
welders having a pacemaker should consult their physician
before welding.
2.c. Exposure to EMF fields in welding may have other health
effects which are now not known.
2.d. All welders should use the following procedures in order to
minimize exposure to EMF fields from the welding circuit:
2.d.1.
Route the electrode and work cables together - Secure
them with tape when possible.
2.d.2. Never coil the electrode lead around your body.
2.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.
2.d.4. Connect the work cable to the workpiece as close as
possible to the area being welded.
2.d.5. Do not work next to welding power source.
Mar ‘95
Page 3
ii
SAFETY
ii
ELECTRIC SHOCK can
kill.
3.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.
3.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 lying, 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.
3.c. In semiautomatic or automatic wire welding, the electrode,
electrode reel, welding head, nozzle or semiautomatic
welding gun are also electrically “hot”.
3.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.
3.e. Ground the work or metal to be welded to a good electrical
(earth) ground.
ARC RAYS can burn.
4.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.
4.b. Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
the arc rays.
4.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
can be dangerous.
5.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
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.f.
Maintain the electrode holder, work clamp, welding cable and
welding machine in good, safe operating condition. Replace
damaged insulation.
3.g. Never dip the electrode in water for cooling.
3.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.
3.i. When working above floor level, use a safety belt to protect
yourself from a fall should you get a shock.
3.j. Also see Items 6.c. and 8.
5.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.
5.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.
5.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.
5.e. Also see item 1.b.
Mar ‘95
vapors
to
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Page 4
iii
SAFETY
iii
WELDING SPARKS can
cause fire or explosion.
6.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.
6.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.
6.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.
6.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).
6.e. Vent hollow castings or containers before heating, cutting or
welding. They may explode.
6.f.
Sparks and spatter are thrown from the welding arc. Wear oil
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.
6.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.
6.h. Also see item 1.c.
Remember that welding sparks and hot
though
they have
Preparation
for Welding and Cutting of
CYLINDER may explode
if damaged.
7.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.
7.b. Always keep cylinders in an upright position securely
chained to an undercarriage or fixed support.
7.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.
7.d. Never allow the electrode, electrode holder or any other
electrically “hot” parts to touch a cylinder.
7.e. Keep your head and face away from the cylinder valve outlet
when opening the cylinder valve.
7.f. Valve protection caps should always be in place and hand
tight except when the cylinder is in use or connected for
use.
7.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.
8.a. Turn off input power using the disconnect
switch at the fuse box before working on
the equipment.
8.b. Install equipment in accordance with the U.S. National
Electrical Code, all local codes and the manufacturer’s
recommendations.
8.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.
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Mar ‘95
Page 5
iv
SAFETY
iv
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 suivantes:
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
metallique 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
defonctionnement.
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.
5. Toujours porter des lunettes de sécurité dans la zone de
soudage. Utiliser des lunettes avec écrans lateraux dans les
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
échauffement 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
produit 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
rayonnement 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.
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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
Mar. ‘93
Page 6
MASTER TABLE OF CONTENTS FOR ALL SECTIONS
vi
RETURN TO MAIN INDEX
INSTALLATION .......................................................................................................................SECTION A
(2) Input voltage must be within ±10% of rated value.
(3) For 1 phase use on 208 or 230 VAC input with output usage above 175A/60% or 200A/35%, the #10 input line cord supplied with the unit should be changed to a
#8 or larger conductor cord.
(†)
200 & 208VAC input may not meet NEMA/IEC specifications at 250 Amps.
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The Invertec V250-S will operate in harsh environments. Even so, it is important that simple preventative measures are followed in order to assure long life
and reliable operation.
HIGH FREQUENCY PRECAUTIONS
If possible locate the V250-S away from radio controlled machinery. The normal operation of the
V250-S may adversely affect the operation of RF controlled equipment, which may result in bodily injury or
damage to the equipment.
INPUT CONNECTIONS
The Invertec V250-S should be connected only by a
qualified electrician. Installation should be made in
accordance with all local and national electric codes
and the information detailed below.
GROUND CONNECTION
Ground per National Electrical Code for 60Hz
machines connect the green lead to earth ground.
For 50/60Hz machines connect the ground terminal
marked located in the machine on the lower right
side the base of the welder to earth ground.
INPUT SUPPLY CONNECTIONS
Be sure the voltage phase and frequency of the input
power is as specified on the rating plate, located on
the rear of the machine.
• The machine must be located where there is free circulation of clean air such that air movement in the
back and out the front will not be restricted.
• Dirt and dust that can be drawn into the machine
should be kept to a minimum. Failure to observe
these precautions can result in excessive operating
temperatures and nuisance shutdown.
• Keep machine dry. Shelter from rain and snow. Do
not place on wet ground or in puddles.
STACKING
V250-S’s cannot be stacked.
TILTING
Place the machine directly on a secure, level surface
or on a recommended undercarriage. The machine
may topple over if this procedure is not followed.
Supply line entry provision is in the case rear panel.
POWER INPUT CONNECTION FOR 60HZ
MACHINES
A 10 ft. power cord is provided and wired into the
machine. Follow the power cord connection instructions. Incorrect connection may result in equipment
damage.
Single Phase Input:
per U.S. National Electrical Code. Connect black and
white leads to power. Wrap red lead with tape to provide 600V insulation.
Three Phase Input:
per U.S. National Electrical Code. Connect black, red
and white leads to power.
Connect green lead to ground
Connect green lead to ground
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INVERTEC V250-S
Page 10
A-4
INSTALLATION
A-4
POWER INPUT CONNECTION FOR 50/60 HZ
MACHINES
1. Connect terminal marked to earth ground
per National Electric Code.
2. Connect the supply lines to the line switch. Torque
to 3.0 Nm.
3. Install in accordance with all local and national
electric codes.
The Invertec V250-S 50/60 Hz machine is supplied
with one cord connector. The cord connector provides
a strain relief for the input power cord as it passes it
through the rear access hole. The cord connector is
designed for a cord diameter of 7.9 to 27.2mm (.310
to 1.070 in).
Strip away outer jacket of cord, trim fillers and insert
conductors through cord connector. The jacketed portion of the cord must go through the cord connector.
Tighten both connector screws.
INPUT FUSE AND SUPPLY WIRE
Refer to the
beginning of this chapter for the proper fuse sizes and
supply cable sizes.
• Fuse the input circuit with recommended super lag
fuses or delay type circuit breakers.
Technical Specifications
page at the
INPUT VOLTAGE RECONNECT
PROCEDURE
When received directly from the factory, units are connected for the highest input voltage, 440 VAC for
50/60 Hz machines and 460 VAC for 60 Hz machines.
If 440 or 460 VAC is the desired input, then the
machine may be connected to the power system without any setup required inside the reconnect door.
However, verify the connection with the following procedure. For other voltages refer to the instructions
located on the Reconnect Panel Access Door or follow the instructions below.
CAUTION
Failure to follow these instructions can cause immediate failure of components within the welder.
1. Open the access door on the right side of the
machine.
2. For 200-230: Position the large switch to 200-230.
For 380-460: Position the large switch to 380-460.
3. Move the “A” lead to the appropriate terminal.
Refer to figure A.1 below.
• Install the proper fuse in the fuse holder in the main
disconnect panel.
RECONNECT PROCEDURE
1. BE SURE POWER SWITCH IS OFF.
2. CONNECT LEAD 'A' TO DESIRED
INPUT VOLTAGE RANGE.
440-460V
380-415V
220-230V
200-208V
3. POSITION SWITCH TO DESIRED INPUT VOLTAGE RANGE.
VOLTAGE=380-460V
THE LINCOLN ELECTRIC CO. CLEVELAND, OHIO U.S.A.
Figure A.1 Input Voltage Reconnect Instructions
'A'
IF MACHINE CEASES TO OPERATE (NO METER, NO FAN)
AND THERE IS NO OTHER KNOWN FAILURE: CHECK FUSE;
REPLACE WITH SPECIFIED FUSE.
.
Disconnect input power before
inspecting or servicing machine.
.
Do not operate with wraparound
removed.
.
Do not touch electrically live parts.
.
Only qualified persons should install,
use or service this equipment.
VOLTAGE=200-230V
A
S21230
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INVERTEC V250-S
Page 11
A-5
INSTALLATION
A-5
OUTPUT CONNECTIONS
Refer to figure A.2 for the location of the 6 Pin Remote
Receptacle and the Output Terminals.
SMAW
SMAW
6 PIN
REMOTE
RECEPTACLE
SOFT
REMOTE
GTAW
CRISP
LOCAL
-
THERMAL
A
120
85
OUTPUT
50
15
1
250
INVERTEC V250-S
+
HOT START
5
6
4
3
2
1
0
170
ARC FORCE
230
5
6
4
3
2
1
0
¤
I
O
7
8
9
10
7
8
9
10
S
QUICK DISCONNECT PLUGS
A quick disconnect system is used for the welding
cable connections. The welding plug included with the
machine is designed to accept a welding cable size of
1/0 to 2/0.
1. Remove 1 in. (25mm) of welding cable insulation.
2. Slide rubber boot onto cable end. The boot end
may be trimmed to match the cable diameter.
Soap or other lubricant will help to slide the boot
over the cable.
BOOT
WELDING CABLE
25 mm
1 in.
TRIM
OUTPUT TERMINALS
FIGURE A.2 OUTPUT CONNECTIONS
REMOTE CONTROL RECEPTACLE
Remote control (K857), Arc start switch (K814), Hand
amptrol (K963) and Foot amptrol (K870) connect
directly to 6 pin amphenol on the front of the unit.
OUTPUT CABLES
Select the output cable size based on Table A.1.
TABLE A.1
Cable Sizes for Combined Length of Electrode and
Work Cable ( Copper Cable Rated at 75°C).
LengthCable Size
up to 150 ft.(46m)1/0 (50mm2)
up to 250 ft.(72m)2/0 (70mm2)
3.Slide the copper tube into the brass plug.
4.Insert cable into copper tube.
5.Tighten set screw to collapse copper tube. Screw
must apply pressure against welding cable. The
top of the set screw will be well below the surface
of the brass plug after tightening.
SET SCREW
BRASS PLUG
COPPER TUBE
6.Slide rubber boot over brass plug. The rubber
boot must be positioned to completely cover all
electrical surfaces after the plug is locked into the
receptacle.
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INVERTEC V250-S
Page 12
A-6
NOTES
A-6
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INVERTEC V250-S
Page 14
B-2
OPERATION
B-2
Read and understand this entire section before
operating your machine.
SAFETY INSTRUCTIONS
WARNING
ELECTRIC SHOCK can kill.
• Do not touch electrically live parts such
as output terminals or internal wiring.
• Insulate yourself from the work and
ground.
• Always wear dry insulating gloves.
____________________________________
FUMES AND GASES
can be dangerous.
• Keep your head out of fumes.
• Use ventilation or exhaust to
remove fumes from breathing
zone.
____________________________________
WELDING, CUTTING and
GOUGING SPARKS
can cause fire or explosion
GENERAL DESCRIPTION
The Invertec V250-S is a 250 amp arc welding power
source that utilizes single or three phase input power,
to produce constant current output. The welding
response of this Invertec has been optimized for stick
(SMAW) and TIG (GTAW).
OPERATIONAL FEATURES
The Invertec V250-S provides continuous total range
output current adjustment, selectable welding modes
and local or remote output control. Welding characteristics can be controlled via an arc force control.
Additionally, starting characteristics can be adjusted
via a “hot start” control.
WELDING CAPABILITY
The Invertec V250-S is rated at 250 amps, 35% duty
cycle (based on a 10 minute cycle). It is also rated at
165 amps, 100% duty cycle, and 200 amps, 60% duty
cycle.
LIMITATIONS
The V250-S is not recommended for pipe thawing.
The V250-S should not be powered from the auxiliary
power supply of an engine welder. Special protection
circuits may operate causing loss of output.
____________________________________
____________________________________
Only qualified personnel should operate this equipment. Observe all safety information throughout this
manual.
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• Keep flammable material away.
• Do not weld, cut or gouge on
containers that have held com-
bustibles.
ARC RAYS
can burn.
• Wear eye, ear and body
protection.
INVERTEC V250-S
Page 15
B-3
OPERATION
B-3
CONTROLS AND SETTINGS
All operator controls and adjustments are located on the case front of the V250-S. Refer to Figure B.1 and corresponding explanations.
FIGURE B.1 — CASE FRONT CONTROLS.
4
SMAW
SOFT
GTAW
SMAW
CRISP
THERMAL
2
A
OUTPUT
3
REMOTE
LOCAL
50
15
120
85
1
INVERTEC V250-S
-
+
250
170
230
8
HOT START
5
6
4
0
ARC FORCE
5
4
0
I
7
8
9
10
6
7
8
9
10
5
6
S
3
2
1
3
2
1
®
1
O
7
1. Power Switch - Place the lever in the “ON” position
to energize the machine. When the power is on, the
fan will operate and the output will be energized in
SMAW modes. GTAW mode requires remote trigger to energize the output.
2. Output Control - This controls the output current.
Control is provided over the entire output range of
the power source with 1 turn of the control knob.
This control may be adjusted while under load to
change power source output. When using remote
control this function becomes the limit setting.
3. Local/Remote Switch - Place in the “LOCAL” position to allow output adjustment at the machine.
Place in the “REMOTE” position to allow output
adjustment at remote pot or amptrol. In Remote, the
machine output control pot is the limit setting for
remote control.
4. Mode Switch
GTAW
Optimized for touch start use. Triggering at
amphenol is required using an Arc Start Switch,
Amptrol or similar means. Short circuit current is
limited to approximately 25 amps to aid in touch
starting.
CC Soft
Best for EXX18 thru EXX28 stick elec-
trodes. Output energized when machine is on.
CC Crisp
Use this mode for stick welding with
EXX10 thru EXX14 electrodes. Output energized
when machine is on.
5. Hot Start - Controls the amount of starting energy
in SMAW.
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INVERTEC V250-S
Page 16
B-4
OPERATION
B-4
6. Arc Force - This control functions in SMAW modes
to adjust the Arc Force. The arc is soft at the minimum settings and more forceful or driving at the
maximum settings. Higher spatter levels may be
present at the maximum settings.
RECOMMENDED ARC FORCE/INDUCTANCE
SETTINGS FOR SELECTED APPLICATIONS
FULL RANGE IS 1-10. 1 is VERY SOFT,
10 IS VERY CRISP
NominalRecommended
ModeProcessSettingAdjustment Range
CC SMAW 1EXX18 thru51 (gentle, may stick) to 9
(soft)EXX28 stick(forceful, more spatter)
CC SMAW 2EXX10 thru63 to 10
(crisp)EXX14 stick
Air Carbon Arc1None
Cutting
7. Output Terminals - These quick disconnect terminals provide connection points for the electrode and
work cables. Refer to
Installation chapter for proper cable sizes. For
positive polarity welding connect the electrode
cable to the positive terminal and the work cable to
the negative terminal. To weld negative polarity
reverse the electrode and work cables.
Output Connections
in the
CONSTANT CURRENT PROCESSES
MANUAL ARC WELDING (STICK)
The Invertec may be utilized as a manual DC arc
welder with the electrode cable, work cable, and electrode holder being the only equipment required.
AIR CARBON ARC CUTTING
Air carbon arc cutting may be performed with the
Invertec within its output rating using 5/32" (3.9mm)
and 3/16" (4.7mm) diameter carbon rods. Output
cables, an air carbon arc electrode cable assembly,
and a source of compressed air are required.
NOTE:
1. Best performance will be at settings of 200 amps
and below.
2. The electronic protection circuit in the V250S will
limit the current to approximately 290 amps.
TIG WELDING
The V250S is capable of touch start TIG welding. An
electrode cable, work cable, Arc Start Switch or
Amptrol, TIG torch, and gas supply with regulator are
required. Refer to
Touch starting is done as follows:
Accessories
section of this manual.
8. Thermal Shutdown Indicator - This light will illuminate if an internal thermostat has been activated.
Machine output will return after the internal
components have returned to a normal operating
temperature. See
chapter.
Thermal Protection
later in this
1. Place the shield cup edge on the work piece.
2. Rock the tungsten down to touch.
3. Trigger the output.
4. Gently rock back the tungsten from the workpiece.
Note: The short circuit current is limited to 25 amps to
aid in touch starting. Panel output control
becomes the current limit setting when in
remote control
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INVERTEC V250-S
Page 17
B-5
OPERATION
PARALLEL OPERATION
The Invertec’s are operable in parallel. For best
results, the currents of each machine should be reasonably well shared. As an example, with two
machines set up in parallel for a 300 amp procedure,
each machine should be set to deliver approximately
150 amps, not 200 amps from one and 100 amps
from the other. This will minimize nuisance feedback
conditions. In general, more than two machines in parallel will not be effective due to the voltage requirements of procedures in that power range.
To set machine outputs, start with output control pots
and arc force pots in identical positions. Adjust outputs and arc forces to maintain current sharing while
establishing the proper output current.
OVERLOAD PROTECTION
The machine is electrically protected from producing
high output currents. Should the output current
exceed 290A, an electronic protection circuit will
reduce the current to less than 200A. The machine
will continue to produce this low current until the protection circuit is reset. Reset occurs when the output
load is removed.
B-5
THERMAL PROTECTION
Thermostats protect the machine from excessive
operating temperatures. Excessive temperatures may
be caused by a lack of cooling air or operating the
machine beyond the duty cycle and output rating. If
excessive operating temperature should occur, the
thermostats will prevent output voltage or current.
Thermostats are self-resetting once the machine cools
sufficiently. If the thermostat shutdown was caused by
excessive output or duty cycle and the fan is operating
normally, the Power Switch may be left on and the
reset should occur within a 15 minute period. If the fan
is not turning or the air intake louvers were obstructed,
then the power must be switched off for 15 minutes in
order to reset. The fan problem or air obstruction must
also be corrected.
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INVERTEC V250-S
Page 18
B-6
NOTES
B-6
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INVERTEC V250-S
Page 20
C-2
ACCESSORIES
OPTIONS / ACCESSORIES
CABLE PLUGS
K852-70 - Cable Plug Kit for 1/0-2/0 cable. Attaches
to welding cable to provide quick disconnect from
machine.
K852-95 - Cable Plug Kit for 2.0-3/0 cable.
NOTE: Two K852-70 plugs are included with the
V250-S.
REMOTE CONTROLS
K857 - Remote Output Control for stick welding.
K963 - Hand Amptroltmfor TIG welding. When the
V250-S’s Output Control is in the “Remote” position,
the hand Amptrol energizes the output and controls
the output remotely. The Hand Amptrol connects
directly to the 6 pin Amphenol.
C-2
K870 - Foot Amptroltmfor TIG welding. When the
V250-S’s Output Control is in the “REMOTE” position,
the foot Amptrol energizes the output and controls the
output remotely. The Hand Amptrol connects directly
to the 6 pin Amphenol.
K814 - Arc Start Switch. Energizes the output for TIG
welding if remote output control of the amperage is
not desired. When using the Arc Start Switch set the
Output Control to the “LOCAL” position.
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1. Turn off input power or disconnect input power
lines.
2. Remove the 5/16" hex head screws from the side
and top of the machine and remove wrap-around
machine cover.
3. Be careful not to make contact with the capacitor
terminals that are located in the top and bottom of
the Power Board.
4. Obtain a high resistance and high wattage resistor
(25-1000 ohms and 25 watts minimum). This resistor is not supplied with machine. NEVER USE A
SHORTING STRAP FOR THIS PROCEDURE.
5. Locate the four capacitor terminals (large hex head
cap screws) shown in Figure D.1. One pair at the
top and one pair at the bottom of the Power Board.
6. Use electrically insulated gloves and insulated pliers. Hold body of the resistor and connect resistor
leads across the two capacitor terminals. Hold
resistor in place for 10 seconds. DO NOT TOUCH
CAPACITOR TERMINALS WITH YOUR BARE
HANDS.
7. Repeat discharge procedure for the capacitor on
other two terminals.
8. Check voltage across terminals of all capacitors
with a DC voltmeter. Polarity of capacitor terminals
is marked on PC board above terminals. Voltage
should be zero. If any voltage remains, repeat this
capacitor discharge procedure.
FIGURE D.1 — LOCATION OF INPUT FILTER CAPACITOR TERMINALS.
POWER
BOARD
RIGHT SIDE OF MACHINE
CAP ACIT OR TERMINALS
UPPER
LOWER
CAPACITOR
TERMINALS
POWER
RESISTOR
INSULATED
PLIERS
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INSULATED
GLOVES
INVERTEC V250-S
Page 23
D-3
MAINTENANCE
D-3
ROUTINE MAINTENANCE
1.Perform the following preventive maintenance
procedures at least once every six months. It is
good practice to keep a preventive maintenance
record; a record tag attached to the machine
works best.
2.Remove the machine wrap-around cover and perform the input filter capacitor discharge procedure
(detail at the beginning of this chapter).
3.Keeping the machine clean will result in cooler
operation and higher reliability. Be sure to clean
the following areas with a low pressure air
stream. See figure D.2 for component locations.
•Power and control printed circuit boards
•Power switch
•Main transformer
•Input rectifier
•Heat sink fins
• Input Filter Capacitors
• Output Terminals
FILTER CAPACITOR
CONDITIONING
A protection circuit is included to monitor the voltage
across filter capacitors C1 and C2. In the event that
the capacitor voltage is too high, the protection circuit
will prevent output. Nominal trip setting is at 230/460
VAC +15%. Reset occurs about 3% lower (230/460
VAC +12%).
On new installations, the protection circuit may also
prevent output providing all these circumstances are
met:
1. Machine is connected for 380-415 or 440-460
VAC input.
2. Machine did not have power applied for many
months.
3. Machine will not produce output when power is
first switched on.
If these circumstances apply, the proper action is to
switch the machine on and let it idle for up to 30 minutes. This is required to condition the filter capacitors
after an extended storage time. The protection circuit
will automatically reset once the capacitor conditioning
and resultant voltage levels are acceptable. It may be
necessary to turn the power switch off and back on
again after this period.
4. Examine capacitors for leakage or oozing. Replace
if needed.
5.Examine the sheet metal case for dents or break-
age. Repair the case as required. Keep the case
in good condition to ensure that high voltage
parts are protected and correct spacings are
maintained. All external sheet metal screws must
be in place to assure case strength and electrical
ground continuity.
6. Check electrical ground continuity. Using an ohmmeter, measure resistance between either output
terminal and an unpainted surface of the machine
case. (See Figure D.2 for locations.) Meter reading
should be 500,000 ohms or more. If meter reading
is less than 500,000 ohms, check for electrical
components that are not properly insulated from
the case. Correct insulation if needed.
7. Replace machine cover and screws.
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INVERTEC V250-S
Page 24
D-4
MAINTENANCE
FIGURE D.2 — LOCATION OF MAINTENANCE COMPONENTS.
D-4
CONTROL PC BOARD
POWER SWITCH
OUTPUT TERMINALS
OUTPUT RECTIFIER
HEATSINK FINS
INPUT RECTIFIER
POWER PC BOARD
COOLING FANS
MAIN TRANSFORMER
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AUXILIARY TRANSFORMER
INVERTEC V250-S
Page 25
E-1
THEORY OF OPERATION
TABLE OF CONTENTS
-THEORY OF OPERATION SECTION-
GENERAL DESCRIPTION...........................................................................................................E-2
INPUT LINE VOLTAGE................................................................................................................E-2
PRE-CHARGE AND PROTECTION............................................................................................E-3
MAIN TRANSFORMER................................................................................................................E-4
OUTPUT RECTIFICATION AND CONTROL...............................................................................E-5
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INVERTEC V250-S
Page 26
E-2
THEORY OF OPERATION
E-2
GENERAL DESCRIPTION
The Invertec V250-S is a 250 amp arc welding power source that utilizes either single or three phase input power
to produce a constant current output. The output response of this machine has been optimized for the SMAW
and TIG welding processes.
FIGURE E.1 - INPUT VOLTAGE CIRCUITS
INPUT
LINE
SWITCH
FAN
MOTORS
INPUT
RECTIFIER
A"
"
L
E
A
D
AUXILIARY
TRANSFORMER
R
E
C
O
N
N
E
C
T
S
W
I
T
C
H
18VAC
POWER BOARD
CR1
RELAY
IGBT
CAPACITOR
IGBT
IGBT
CAPACITOR
IGBT
O
V
E
R
V
O
L
T
A
G
E
PROTECTION SIGNAL
CR1 RELAY DRIVE SIGNAL
CURRENT
TRANSFORMER
GATE SIGNALS
IGBT
REMOTE
RECEPTACLE
MAIN
TRANSFORMER
CONTROL BOARD
OUTPUT
CONTROL
THERMOSTATS
STRIKE
CONTROL
SHUNT
ARC
FORCE
CONTROL
F
E
E
D
B
A
C
K
MODE
SWITCH
F
E
E
D
B
A
C
K
LOCAL/
REMOTE
SWITCH
POSITIVE
OUTPUT
TERMINAL
NEGATIVE
OUTPUT
TERMINAL
THERMAL
LIGHT
INPUT LINE VOLTAGE
The single-phase or three-phase input power of 208,
230 or 460 volts AC is connected to the machine,
through a line switch located on the front panel.
A reconnect panel and switch allows the user to configure the machine for either a low or high input voltage and also connect the auxiliary transformer for the
appropriate input voltage.
The auxiliary transformer develops the appropriate AC
voltages to operate the cooling fans and the control
board.
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NOTE: Unshaded areas of block logic diagrams are the subject of discussion.
INVERTEC V250-S
Page 27
E-3
THEORY OF OPERATION
FIGURE E.2 PROTECTION AND PRE-CHARGE CIRCUITS
E-3
INPUT
LINE
SWITCH
FAN
MOTORS
INPUT
RECTIFIER
A"
"
L
E
A
D
AUXILIARY
TRANSFORMER
R
E
C
O
N
N
E
C
T
S
W
I
T
C
H
18VAC
POWER BOARD
CR1
RELAY
IGBT
CAPACITOR
IGBT
IGBT
CAPACITOR
IGBT
O
V
E
R
V
O
L
T
A
G
E
PROTECTION SIGNAL
CR1 RELAY DRIVE SIGNAL
CURRENT
TRANSFORMER
GATE SIGNALS
IGBT
REMOTE
RECEPTACLE
MAIN
TRANSFORMER
CONTROL BOARD
OUTPUT
CONTROL
THERMOSTATS
STRIKE
CONTROL
SHUNT
ARC
FORCE
CONTROL
F
E
E
D
B
A
C
K
MODE
SWITCH
F
E
E
D
B
A
C
K
LOCAL/
REMOTE
SWITCH
POSITIVE
OUTPUT
TERMINAL
NEGATIVE
OUTPUT
TERMINAL
THERMAL
LIGHT
PRECHARGE AND PROTECTION
The input voltage is rectified and the DC voltage is
applied, through the reconnect switch, to the power
board. The power board contains precharging circuitry for the safe charging of the input filter capacitors.
Once the capacitors are precharged and balanced the
control board activates the CR1 input relay which connects full input power to the filter capacitors. When
the filter capacitors are fully charged they act as
power supplies for the IGBT switching circuit. The
Insulated Gate Bipolar Transistors supply the main
transformer primary windings with DC current flow.
See
IGBT Operation Discussion and diagrams
this section.
The power board also monitors the filter capacitors for
voltage balance and/or overvoltage and, if either
should occur, sends the appropriate signal to the control board to deactivate the CR1 input relay. The
machine output will also be disabled.
in
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NOTE: Unshaded areas of block logic diagrams are the subject of discussion.
INVERTEC V250-S
Page 28
E-4
THEORY OF OPERATION
FIGURE E.3 MAIN TRANSFORMER
E-4
INPUT
LINE
SWITCH
FAN
MOTORS
INPUT
RECTIFIER
A"
"
L
E
A
D
AUXILIARY
TRANSFORMER
R
E
C
O
N
N
E
C
T
S
W
I
T
C
H
18VAC
POWER BOARD
CR1
RELAY
IGBT
CAPACITOR
IGBT
IGBT
CAPACITOR
IGBT
O
V
E
R
V
O
L
T
A
G
E
PROTECTION SIGNAL
CR1 RELAY DRIVE SIGNAL
CURRENT
TRANSFORMER
GATE SIGNALS
IGBT
REMOTE
RECEPTACLE
MAIN
TRANSFORMER
CONTROL BOARD
OUTPUT
CONTROL
THERMOSTATS
STRIKE
CONTROL
SHUNT
ARC
FORCE
CONTROL
F
E
E
D
B
A
C
K
MODE
SWITCH
F
E
E
D
B
A
C
K
LOCAL/
REMOTE
SWITCH
POSITIVE
OUTPUT
TERMINAL
NEGATIVE
OUTPUT
TERMINAL
THERMAL
LIGHT
MAIN TRANSFORMER
Each IGBT pair acts as a switch assembly. Each
assembly feeds a separate, oppositely wound primary
winding of the main transformer. The reverse directions of current flow through the main transformer primaries and the offset timing of the IGBT pairs induce
an AC square wave output signal at the secondary of
the main transformer.
The DC current flow through each primary winding is
redirected or “clamped” back to each respective filter
capacitor when the IGBTs are turned off. This is
needed due to the inductance of the transformer primary winding.
The primary currents also pass through the current
transformer which sends a signal to the control board.
If the primary currents are not equal the control board
compensates by adjusting the IGBT gate signals.
The firing of both IGBT pairs occurs during halves of
the 50 microsecond intervals, creating a constant 20
KHZ output.
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NOTE: Unshaded areas of block logic diagrams are the subject of discussion.
INVERTEC V250-S
Page 29
E-5
THEORY OF OPERATION
FIGURE E.4 OUTPUT RECTIFICATION AND CONTROL
E-5
INPUT
LINE
SWITCH
FAN
MOTORS
INPUT
RECTIFIER
A"
"
L
E
A
D
AUXILIARY
TRANSFORMER
R
E
C
O
N
N
E
C
T
S
W
I
T
C
H
18VAC
POWER BOARD
CR1
RELAY
IGBT
CAPACITOR
IGBT
IGBT
CAPACITOR
IGBT
O
V
E
R
V
O
L
T
A
G
E
PROTECTION SIGNAL
CR1 RELAY DRIVE SIGNAL
CURRENT
TRANSFORMER
GATE SIGNALS
IGBT
REMOTE
RECEPTACLE
MAIN
TRANSFORMER
CONTROL BOARD
OUTPUT
CONTROL
THERMOSTATS
STRIKE
CONTROL
SHUNT
ARC
FORCE
CONTROL
F
E
E
D
B
A
C
K
MODE
SWITCH
F
E
E
D
B
A
C
K
LOCAL/
REMOTE
SWITCH
POSITIVE
OUTPUT
TERMINAL
NEGATIVE
OUTPUT
TERMINAL
THERMAL
LIGHT
OUTPUT RECTIFICATION
AND CONTROL
The AC output from the main transformer secondary
is rectified to a DC output and applied to the output
terminals. Output voltage and current feedback information, which is fed to the control board, is sensed at
the output terminals and shunt. The control board
monitors the panel controls and remote control receptacle and compares these commands to the feedback
information to determine how the output should be
controlled to optimized welding results. The control
board controls the IGBT switching through pulse width
modulation circuitry. See
in this section.
IGBT Operation
Discussion
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NOTE: Unshaded areas of block logic diagrams are the subject of discussion.
INVERTEC V250-S
Page 30
E-6
THEORY OF OPERATION
PROTECTION CIRCUITS
Protective circuits are designed into the V250-S
machine to sense trouble and shut down the machine
before the trouble damages the internal machine components. Both overload and thermal protection circuits are included.
E-6
OVERLOAD PROTECTION
The V250-S is electrically protected from producing
high output currents. Should the output current
exceed 290 amps, an electronic protection circuit will
reduce the current to less than 200 amps. Lincoln
Electric refers to this current reduction as “Fold Back”.
The machine will continue to produce this low current
until the protection circuit is reset. Reset occurs when
the output load is removed.
A protection circuit is included to monitor the voltage
across the input filter capacitors. In the event that the
capacitor voltage is too high, the protection circuit will
prevent output.
On new installations, the protection circuit may prevent output, due to unbalanced capacitor leakages,
providing the following circumstances are met:
1. Machine is connected for 380 - 460VAC input.
2. Machine did not have power applied for many
months.
3. Improper connections.
THERMAL PROTECTION
Thermostats protect the machine from excessive
operating temperatures. Excessive temperatures may
be caused by a lack of cooling air or operating the
machine beyond the duty cycle and output rating. If
excessive operating temperature should occur, the
thermostat will prevent output voltage or current and
the thermal indicator light will glow.
Thermostats are self-resetting once the machine cools
sufficiently. If the thermostat shutdown was caused
be excessive output or duty cycle and the fan is operating normally, the power switch may be left on and
the reset should occur within 15 minute period. If the
fan is not turning or the air intake louvers were
obstructed, then the power must be switched off for 15
minutes in order to reset. The fan problem or air
obstruction must be corrected.
4. Internal component damage.
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NOTE: Unshaded areas of block logic diagrams are the subject of discussion.
An IGBT is a type of transistor. IGBTs are semiconductors well suited for high frequency switching and
high current applications.
Drawing A shows an IGBT in a passive mode. There
is no gate signal, zero volts relative to the source, and
therefore, no current flow. The drain terminal of the
IGBT may be connected to a voltage supply; but since
there is no conduction the circuit will not supply current to components connected to the source. The circuit is turned off like a light switch in the OFF position.
Drawing B shows the IGBT in an active mode. When
the gate signal, a positive DC voltage relative to the
FIGURE E.6 IGBT OPERATION
source, is applied to the gate terminal of the IGBT, it
is capable of conducting current. A voltage supply
connected to the drain terminal will allow the IGBT to
conduct and supply current to circuit components
coupled to the source. Current will flow through the
conducting IGBT to downstream components as long
as the positive gate signal is present. This is similar
to turning ON a light switch.
SOURCE
n +n +
p
n -
n +
p +
DRAIN
A. PASSIVE
GATE
BODY REGION
DRAIN DRIFT REGION
BUFFER LAYER
INJECTING LAYER
SOURCE
n +n +
p
n -
n +
p +
DRAIN
B. ACTIVE
POSITIVE
VOLTAGE
APPLIED
GATE
BODY REGION
DRAIN DRIFT REGION
BUFFER LAYER
INJECTING LAYER
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INVERTEC V250-S
Page 32
E-8
THEORY OF OPERATION
PULSE WIDTH MODULATION
E-8
The term PULSE WIDTH MODULATION is used to
describe how much time is devoted to conduction in
the positive and negative portions of the cycle.
Changing the pulse width is known as MODULATION.
Pulse Width Modulation (PWM) is the varying of the
pulse width over the allowed range of a cycle to affect
the output of the machine.
MINIMUM OUTPUT
By controlling the duration of the gate signal, the IGBT
is turned on and off for different durations during a
cycle. The top drawing below shows the minimum
output signal possible over a 50-microsecond time
period.
1
An IGBT group consists of two IGBT modules feeding one transformer primary winding.
The positive portion of the signal represents one IGBT
group1conducting for 1 microsecond. The negative
portion is the other IGBT group1. The dwell time (off
time) is 48 microseconds (both IGBT groups off).
Since only 2 microseconds of the 50-microsecond
time period is devoted to conducting, the output power
is minimized.
MAXIMUM OUTPUT
By holding the gate signals on for 24 microseconds
each and allowing only 2 microseconds of dwell time
(off time) during the 50-microsecond cycle, the output
is maximized. The darkened area under the top curve
can be compared to the area under the bottom curve.
The more dark area under the curve, the more power
is present.
sec
FIGURE E.7 TYPICAL IGBT OUTPUTS
sec
48
sec
50
MINIMUM OUTPUT
sec
24
sec
2
sec
50
sec
24
sec
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MAXIMUM OUTPUT
INVERTEC V250-S
Page 33
SECTION F-1
TROUBLESHOOTING & REPAIR
SECTION F-1
TABLE OF CONTENTS
-TROUBLESHOOTING & REPAIR SECTION-
TROUBLESHOOTING AND REPAIR SECTION.........................................................................SECTION F
HOW TO USE TROUBLESHOOTING GUIDE.............................................................................F-2
PC BOARD TROUBLESHOOTING PROCEDURES...................................................................F-3
CONTROL BOARD REMOVAL AND REPLACEMENT.......................................................F-43
POWER BOARD REMOVAL AND REPLACEMENT...........................................................F-45
FILTER CAPACITOR REMOVAL AND REPLACEMENT....................................................F-49
INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT ........................................F-53
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT ......................................F-57
(MACHINE CODES BELOW 10150)
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT ......................................F-61
(MACHINE CODES ABOVE 10150)
MAIN TRANSFORMER REMOVAL AND REPLACEMENT................................................F-65
(MACHINE CODES BELOW 10150)
MAIN TRANSFORMER REMOVAL AND REPLACEMENT................................................F-71
(MACHINE CODES ABOVE 10150)
RETEST AFTER REPAIR..........................................................................................................F-77
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INVERTEC V250-S
Page 34
F-2
TROUBLESHOOTING & REPAIR
F-2
HOW TO USE TROUBLESHOOTING GUIDE
WARNING
Service and Repair should only be performed by Lincoln Electric Factory Trained Personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician and
machine operator and will invalidate your factory warranty. For your safety and to avoid
Electrical Shock, please observe all safety notes and precautions detailed throughout this
manual.
This Troubleshooting Guide is provided to
help you locate and repair possible machine
malfunctions. Simply follow the three-step
procedure listed below.
Step 1. LOCATE PROBLEM (SYMPTOM).
Look under the column labeled “PROBLEM
(SYMPTOMS)”. This column describes
possible symptoms that the machine may
exhibit. Find the listing that best describes
the symptom that the machine is exhibiting.
Symptoms are grouped into the following
categories: output problems and welding
problems.
Step 2. PERFORM EXTERNAL TESTS.
The second column labeled “POSSIBLE
AREAS OF MISADJUSTMENT(S)” lists the
obvious external possibilities that may contribute to the machine symptom. Perform
these tests/checks in the order listed. In
general, these tests can be conducted without removing the case wrap-around cover.
Step 3. RECOMMENDED COURSE OF
ACTION
The last column labeled “Recommended
Course of Action” lists the most likely components that may have failed in your
machine. It also specifies the appropriate
test procedure to verify that the subject
component is either good or bad. If there
are a number of possible components,
check the components in the order listed to
eliminate one possibility at a time until you
locate the cause of your problem.
All of the referenced test procedures
referred to in the Troubleshooting Guide are
described in detail at the end of this chapter. Refer to the Troubleshooting and Repair
Table of Contents to locate each specific
Test Procedure. All of the specified test
points, components, terminal strips, etc. can
be found on the referenced electrical wiring
diagrams and schematics. Refer to the
Electrical Diagrams Section Table of
Contents to locate the appropriate diagram.
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CAUTION
If for any reason you do not understand the test procedures or are unable to perform the
tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.
Do not use oscilloscopes and other test equipment which are powered by 115 VAC.
This equipment should not be used with inverter-type machines, such as Invertec
V250-S. There are high voltages present, which are “floating” off case ground (floating
ground). Connecting the ground lead of a test probe (which may be connected to the
case of the test equipment) to a high voltage potential presents a shock hazard as well
as the possibility of damage to the equipment in question.
ELECTRIC SHOCK can kill.
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.
_______________________________
CAUTION: Sometimes machine failures
appear to be due to PC board failures. These
problems can sometimes be traced to poor
electrical connections. To avoid problems
when troubleshooting and replacing PC
boards, please use the following procedure:
1. Determine to the best of your technical
ability that the PC board is the most likely
component causing the failure symptom.
2. Check for loose connections at the PC
board to assure that the PC board is properly connected.
3. If the problem persists, replace the suspect PC board using standard practices to
avoid static electrical damage and electrical shock. Read the warning inside the
static resistant bag and perform the following procedures:
- Remove the P.C. Board from the staticshielding bag and place it directly into the
equipment. Don’t set the P.C. Board on or
near paper, plastic or cloth which could have
a static charge. If the P.C. Board can’t be
installed immediately, put it back in the staticshielding bag.
- If the P.C. Board uses protective shorting
jumpers, don’t remove them until installation
is complete.
- If you return a P.C. Board to The Lincoln
Electric Company for credit, it must be in the
static-shielding bag. This will prevent further
damage and allow proper failure analysis.
4. Test the machine to determine if the failure symptom has been corrected by the
replacement PC board.
NOTE: It is desirable to have a spare (known
good) PC board available for PC board troubleshooting.
NOTE: Allow the machine to heat up so that
all electrical components can reach their operating temperature.
5. Remove the replacement PC board and
substitute it with the original PC board to
recreate the original problem.
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P.C. Board can be damaged by static electricity.
- Remove your body’s static charge before opening
ATTENTION
Static-Sensitive
Devices
Handle only at
Static-Safe
Workstations
Reusable
Container
Do Not Destroy
equipment frame. Keep touching the frame to
prevent static build-up. Be sure not to touch
any electrically live parts at the same time.
- Tools which come in contact with the P.C.
Board must be either conductive, anti-static or
static-dissipative.
the static-shielding bag.
Wear an anti-static wrist
strap. For safety, use a 1
Meg ohm resistive cord
connected to a grounded
part of the equipment
frame.
- If you don’t have a wrist
strap, touch an unpainted,
grounded, part of the
INVERTEC V250-S
a. If the original problem does not reap-
pear by substituting the original
board, then the PC board was not the
problem. Continue to look for bad
connections in the control wiring harness, junction blocks, and terminal
strips.
b. If the original problem is recreated by
the substitution of the original board,
then the PC board was the problem.
Reinstall the replacement PC board
and test the machine.
6. Always indicate that this procedure was
followed when warranty reports are to be
submitted.
NOTE: Following this procedure and writing on the
warranty report, “INSTALLED AND SWITCHED PC
BOARDS TO VERIFY PROBLEM,” will help avoid
denial of legitimate PC board warranty claims.
Page 36
F-4
TROUBLESHOOTING & REPAIR
Observe all Safety Guidelines detailed throughout this manual
F-4
PROBLEMS
(SYMPTOMS)
Major physical or electrical damage
is observed when cover wrap-around
is removed.
The machine is dead - no output no fan.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
Contact your local Lincoln
Authorized Field Service Facility.
1. The input power switch must be
in the ON position.
2. Make sure the input voltage is
correct for the machine.
3. If the machine is set for singlephase operation, inspect to
assure that the WHITE and
BLACK leads are connected
properly and the RED lead is not
connected and is insulated.
4. Check that the input voltage setup switch and jumper “A” (the
reconnect auxiliary jumper) are in
the proper position for the input
voltage being applied. Refer to
Input Voltage Reconnect
Procedure
Chapter.
in the Installation
RECOMMENDED
COURSE OF ACTION
Contact Lincoln Electric Service
Department (216)-383-2531 or
1-800-833-9353
1. The power switch (S1) may be
faulty. Check or replace.
2. Check for loose or broken leads
between the power switch (S1)
and the input rectifier D9. See
wiring diagram.
3. Perform the
Transformer Test
Auxiliary
.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.
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5. Check continuity of the 0.6-amp
slow blow fuse located on the
reconnect panel.
CAUTION
INVERTEC V250-S
Page 37
F-5
TROUBLESHOOTING & REPAIR
Observe all Safety Guidelines detailed throughout this manual
F-5
PROBLEMS
(SYMPTOMS)
No output but the fan operates normally.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. The mode switch must be in one
of the SMAW modes or if in the
GTAW mode the remote trigger
circuit must be activated.
2. The Local/Remote switch (S3)
must be in the LOCAL position
unless a remote control device is
attached to the remote
receptacle.
3. If the machine has not been used
for a long time and is connected
for 380 VAC or higher, the
capacitors may need “conditioning”. See
Conditioning
4. The machine may be overheated.
Check the thermal indicator light.
Wait for the machine to cool and
the thermostats to reset.
Input Filter Capacitor
.
RECOMMENDED
COURSE OF ACTION
1. Perform the
Transformer Test
2. Check for loose or broken
connections on the high current
carrying parts of the V250-S.
(i.e., output diodes, output
terminals, shunt and main
transformer connections.)
3. Check the continuity of the
normally closed thermostats and
associated wiring. See wiring
diagram.
4. Perform the
5. Perform the
Test
.
6. Perform the
Test
.
Auxiliary
.
Output Diode Test
Capacitor Balance
Protection Circuit
.
CAUTION
7. Perform the
Voltage Checks
8. Perform the
Voltage Checks
Power Board
.
Control Board
.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.
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INVERTEC V250-S
Page 38
F-6
TROUBLESHOOTING & REPAIR
Observe all Safety Guidelines detailed throughout this manual
F-6
PROBLEMS
(SYMPTOMS)
Output turns on momentarily, then
switches off and repeats cycle.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. Check the input voltages and
reconnection procedures. Make
sure the input voltage is correct
for the machine. See
Voltage Reconnect Procedure
2. Check or replace remote control
device. (If used)
Input
RECOMMENDED
COURSE OF ACTION
1. Check Local/Remote switch (S3)
and associated wiring for loose or
faulty connections.
.
2. Check Mode Switch (S2) and
associated wiring for loose or
faulty connections.
3. If the machine is connected for
380VAC input or higher, perform
the
Capacitor Balance Test
4. The power board may be faulty.
Replace.
5. The control board may be faulty.
Replace.
.
Remote output control not
functioning. The machine operates
normally on LOCAL control.
1. Make sure the Local/Remote
switch (S3) is in the REMOTE
position.
2. The remote control device may
be faulty. Replace.
1. Check the Local/Remote switch
(S3) and the associated wiring.
See wiring diagram.
2. Check for loose or faulty
connections at the remote control
receptacle.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.
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CAUTION
INVERTEC V250-S
Page 39
F-7
TROUBLESHOOTING & REPAIR
Observe all Safety Guidelines detailed throughout this manual
F-7
PROBLEMS
(SYMPTOMS)
No output - Main input fuses open,
indicating excessive current draw.
The machine operates normally
when connected for 200 - 230VAC
input. There is no output when the
machine is connected to 380VAC or
higher.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. Inspect input leads for possible
shorts or grounds or mis-connections.
2. Install new fuses and reapply
power. If fuses open again, consult a Lincoln Authorized Field
Service Facility.
1. Check the input voltage and input
voltage reconnect procedures.
See
Installation Section
manual.
of this
RECOMMENDED
COURSE OF ACTION
1. Inspect interior of machine for
physical signs of electrical and
heat damage. Replace any damaged components after conducting the following tests.
2. Perform the
3. Perform
Resistance Test
4. Check the reconnect switch and
associated leads for “shorts” or
faulty wiring.
1. Perform the
Test
.
2. Perform the
Test
.
Input Rectifier Test
Power Board
.
Capacitor Balance
Protection Circuit
.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.
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CAUTION
INVERTEC V250-S
3. Perform the
Transformer Test
4. Perform the
Resistance Test
Auxiliary
.
Power Board
.
Page 40
F-8
TROUBLESHOOTING & REPAIR
Observe all Safety Guidelines detailed throughout this manual
F-8
PROBLEMS
(SYMPTOMS)
The machine will not produce more
than 200 amps.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. This may be normal operation. If
the output current exceeds 290
amps, an electronic protection
circuit will reduce the current to
less than 200 amps. The
machine will continue to produce
this low current until the
protection circuit is reset. Reset
occurs when the output load is
removed.
2. Check the input voltage and input
voltage reconnect procedures.
See
Input Voltage Reconnect
Procedure
3. Check for loose or faulty welding
cables.
.
RECOMMENDED
COURSE OF ACTION
1. Perform the
2. The control board may be faulty.
Replace.
Output Diode Test
.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.
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CAUTION
INVERTEC V250-S
Page 41
F-9
TROUBLESHOOTING & REPAIR
Observe all Safety Guidelines detailed throughout this manual
F-9
PROBLEMS
(SYMPTOMS)
Poor welding, weld settings drift, or
output power is low.
Poor stick electrode welding
performance. The arc pops out.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
1. Make sure the machine settings
are correct for the weld process
being used.
2. Check machine performance on
LOCAL control. If OK then the
remote control device may be
faulty. Check or replace.
3. Check the input voltages and
input voltage reconnect
procedures. See
Section
1. Check for loose or faulty welding
cables.
2. Is the electrode DRY? Try welding with another electrode from a
different container. Make sure
you have the correct electrode for
the application.
of this manual.
Installation
RECOMMENDED
COURSE OF ACTION
1. Check the operation of the mode
switch (S2) and the associated
circuitry. See wiring diagram.
2. Check for loose or faulty connections in the heavy current carrying
leads (i,e,. output diodes, output
terminals, shunt and main transformer.)
3. Perform
4. Perform
Test
1. Check for loose or faulty connections in the heavy current carrying
leads (i,e,. output diodes, output
terminals, shunt and main transformer.)
2. Perform
Output Diode Test
Control Board Voltage
.
Output Diode Test
.
.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.
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3. Make sure the machine settings
are correct for the weld process
being used.
CAUTION
INVERTEC V250-S
3. Perform
Test
.
Control Board Voltage
Page 42
F-10
NOTES
F-10
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INVERTEC V250-S
Page 43
F-11
TROUBLESHOOTING & REPAIR
AUXILIARY TRANSFORMER TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
7. If the correct test voltages are present the auxiliary transformer is good.
8. If any of the voltages are missing or
very low, with the proper primary
voltage applied, the auxiliary transformer may be faulty. Replace.
F-13
9. If the auxiliary transformer tests good
but does not function when connected to the V250-S check the harness
wiring to the auxiliary transformer.
See wiring diagram.
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INVERTEC V250-S
Page 46
F-14
NOTES
F-14
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INVERTEC V250-S
Page 47
F-15
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
This test will help determine if the input rectifier has “shorted” or “open” diodes.
MATERIALS NEEDED
Analog voltmeter/ohmmeter (Multimeter)
Phillips head screwdriver
Wiring diagram
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INVERTEC V250-S
Page 48
F-16
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER TEST (continued)
TEST PROCEDURE
F-16
1. Remove main input power to the
V250-S.
2. Perform
Procedure
Section.
3. Locate Input Rectifier (D9) and lead
locations.
Filter Capacitor Discharge
detailed in Maintenance
4. With the Phillips head screwdriver
remove leads #207, 207A and #209
from the rectifier. See Figure F.2.
5. Use the analog ohmmeter to perform
the tests detailed in
wiring diagram.
Table F.2.
See
#207
#207A
A
B
C
#209
Figure F.2 Input Rectifier and Leads.
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INVERTEC V250-S
Page 49
F-17
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER TEST (continued)
TABLE F.2 Input Rectifier Test Points
TEST POINT TERMINALSANALOG METER X10 RANGE
+ Probe- ProbeAcceptable Meter Readings
A207Greater than 1000 ohms
B207Greater than 1000 ohms
C207Greater than 1000 ohms
A209Less than 100 ohms
B209Less than 100 ohms
C209Less than 100 ohms
207ALess than 100 ohms
207BLess than 100 ohms
207CLess than 100 ohms
209AGreater than 1000 ohms
209BGreater than 1000 ohms
209CGreater than 1000 ohms
F-17
6. If the Input Rectifier does not meet
the acceptable readings outlined in
Table F.2. the component may be
faulty. Replace.
Note: Before replacing the Input
Rectifier(D9) check the input
power switch (S1) and perform
the
Power Board Resistance
Test
. Also check for leaky or
faulty filter capacitors.
7. When installing a new Input
Rectifier, torque the mounting nuts to
44IN-LBS. A thin coating of Dow
Corning 340 Heat Sink Compound
(Lincoln E1868) is recommended.
Torque the lead terminals to 31INLBS. See
Removal And Replacement
Input Rectifier Bridge
.
8. If the Input Rectifier is good be sure
to reconnect leads #207, #207A and
#209 to the correct terminals and
torque to 31IN-LBS. See wiring diagram and Figure F.2.
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INVERTEC V250-S
Page 50
F-18
NOTES
F-18
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INVERTEC V250-S
Page 51
F-19
TROUBLESHOOTING & REPAIR
POWER BOARD RESISTANCE TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
This test will help determine if the Power Board has any “shorted” or “leaky” power diodes or
Insulated Gate Bipolar Transistors. Also it will help to indicate any “shorted” filter capacitors.
MATERIALS NEEDED
Analog voltmeter/ohmmeter (Multimeter)
Wiring diagram
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INVERTEC V250-S
Page 52
F-20
TROUBLESHOOTING & REPAIR
POWER BOARD RESISTANCE TEST (continued)
TEST DESCRIPTION
F-20
1. Remove main input power to the
V250 -S.
2. Perform
Procedure
Section.
3. Locate the Power Board and associated lead locations. See Figure F.3.
Filter Capacitor Discharge
detailed in Maintenance
201
204
4. Carefully remove main transformer
primary leads #201, #204, #205 and
#208 from the power board.
5. Use the analog ohmmeter to perform
the tests outlined in
power board schematic.
Table F.3
+
207A
202A
. See
DANGER
HIGH VOLTAGE CAN KILL
V250S POWER G2684
209
208
205
203A
Figure F.3 Power Board Test Points.
+
206
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INVERTEC V250-S
Page 53
F-21
TROUBLESHOOTING & REPAIR
POWER BOARD RESISTANCE TEST (continued)
TABLE F.3 Power Board Resistance Test Points.
TEST POINT TERMINALSANALOG METER X10 RANGE
+ Probe- ProbeAcceptable Meter Readings
201207AGreater than 1000 ohms
207A201Less than 100 ohms
204207AGreater than 1000 ohms
207A204Less than 100 ohms
202A204Greater than 1000 ohms
204202ALess than 100 ohms
202A201Greater than 1000 ohms
201202ALess than 100 ohms
205203AGreater than 1000 ohms
203A205Less than 100 ohms
F-21
208203AGreater than 1000 ohms
203A208Less than 100 ohms
206208Greater than 1000 ohms
208206Less than 100 ohms
206205Greater than 1000 ohms
205206Less than 100 ohms
6. If the power board does not meet the
acceptable readings outlined in
Table F.3. the board may be faulty.
Replace. See
Removal and Replacement
Procedure
Note: Complete power board and filter
capacitor replacement is recommended
.
7. If the power board “passes” the
resistance test proceed to the
Board Voltage Test
.
Power Board
Power
.
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Note: Reconnect leads #201, #204,
#205 and #208 to their appropriate terminals.
INVERTEC V250-S
Page 54
F-22
NOTES
F-22
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INVERTEC V250-S
Page 55
F-23
TROUBLESHOOTING & REPAIR
OUTPUT DIODES TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
This test will help determine if any of the output diodes are “shorted”.
MATERIALS NEEDED
Analog voltmeter/ohmmeter (Multimeter)
Wiring diagram. Note: Output diode polarity will vary with machine codes.
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INVERTEC V250-S
Page 56
F-24
TROUBLESHOOTING & REPAIR
OUTPUT DIODES TEST (continued)
F-24
TEST PROCEDURE
1. Remove main input power to the
V250-S.
2. Locate the output terminals on the
front panel of the machine. See
Figure F.4.
3. Remove any output cables and load
from the output terminals.
SMAW
SOFT
GTAW
SMAW
CRISP
A
OUTPUT
50
THERMAL
85
4. Using the analog ohmmeter test for
more than 200 ohms resistance
between positive and negative output terminals. Positive test lead to
the positive terminal; Negative test
lead to the negative terminal. See
Figure F.5.
NOTE: THE POLARITY OF THE TEST
LEADS IS MOST IMPORTANT. IF
THE TEST LEADS POLARITY IS NOT
CORRECT THE TEST WILL HAVE
ERRONEOUS RESULTS.
HOT START
5
6
4
7
8
0
9
10
120
3
2
1
170
NEGATIVE
OUTPUT
TERMINAL
Figure F.4 Machine Output Terminals.
REMOTE
15
LOCAL
1
INVERTEC V250-S
-
+
250
230
3
2
®
POSITIVE
OUTPUT
TERMINAL
ARC FORCE
4
1
0
O
5
6
7
8
9
10
S
I
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INVERTEC V250-S
Page 57
F-25
TROUBLESHOOTING & REPAIR
OUTPUT DIODES TEST (continued)
INVERTEC V250-S
-
- PROBE
+
+ PROBE
F-25
®
S
I
O
Figure F.5 Meter Probes.
5. If more than 200 ohms is measured
the output diodes are not “shorted”.
6. If less than 200 ohms is measured,
one or more output diodes or snubbers may be shorted or “leaky”.
7. Perform
Procedure
Section.
Filter Capacitor Discharge
detailed in Maintenance
8. Locate output diodes and snubbers.
See Figure F.6. for machine codes
10102 and 10103 only. See Figure
F.7. for machine codes 10187 and
10188 only.
9. Test all output diodes and snubbers
(if used) individually.
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INVERTEC V250-S
Page 58
F-26
TROUBLESHOOTING & REPAIR
OUTPUT DIODES TEST (continued)
OUTPUT DIODES
SNUBBERS
F-26
Figure F.6 Output Diodes and Snubber Locations (Codes 10102 and 10103)
DIODE MODULES
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Figure F.7 Output Diode Module Locations (Codes 10187 and 10188)
INVERTEC V250-S
Page 59
F-27
TROUBLESHOOTING & REPAIR
POWER BOARD VOLTAGE TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
This test will aid the technician in determining if the voltage board or some other machine
component may be faulty.
MATERIALS NEEDED
Voltmeter/ohmmeter (Multimeter)
Wiring diagram.
Power board schematic drawing.
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INVERTEC V250-S
Page 60
F-28
N
2
+
+
TROUBLESHOOTING & REPAIR
POWER BOARD VOLTAGE TEST (continued)
F-28
TEST PROCEDURE
1. Remove main input power to the
V250-S.
2. Perform
Procedure
Filter Capacitor Discharge
detailed in Maintenance
Section.
3. Locate and familiarize yourself with
the leads and pin locations in plug J6
on the power board. See Figure F.8.
#309 (6J6)
4. The following tests will be performed
with the input power applied to the
V250-S. BE CAREFUL. ALWAYS
REMOVE INPUT POWER AND
PERFORM FILTER CAPACITOR
DISCHARGE PROCEDURE
BEFORE TOUCHING ANY
MACHINE COMPONENT.
5. Apply input power and turn On the
V250-S.
6. Perform the voltage checks outlined
in
Table F.4
. making sure all of the
test conditions are in effect.
#313 (5J6)
#311 (4J6)
205
#310 (3J6)
209
208
203A
#307 (2J6)
PLUG J6
J6
V250S POWER G2684
DANGER
HIGH VOLTAGE CA
#308 (1J6)
204
201
207A
20
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Figure F.8 Plug J6 on Power Board
INVERTEC V250-S
Page 61
F-29
POWER BOARD VOLTAGE TEST (continued)
TEST DESCRIPTION
TROUBLESHOOTING & REPAIR
TABLE F.4. Power Board Voltage Test Points.
ACCEPTABLE
TEST POINTS
VOLTAGES
F-29
TEST CONDITIONS
The PWM pulse drive from the
control board to the pulse
transformer primary located on
the power board.
The PWM pulse drive from the
control board to the pulse
transformer primary located on
the power board.
The PWM pulse drive from the
control board to the pulse
transformer primary located on
the power board.
The PWM pulse drive from the
control board to the pulse
transformer primary located on
the power board.
Lead #307 (2J6)
to
Negative output terminal
Lead #308 (1J6)
to
Negative output terminal
Lead #307 (2J6)
to
Negative output terminal
Lead #308 (1J6)
to
Negative output terminal
14VDC.
14VDC.
7VDC.
7VDC.
No load on the machine - the
mode switch in SMAW position.
No load on the machine - the
mode switch in SMAW position.
Machine loaded to 250Amps.
The output control R3 at the
maximum position.
Machine loaded to 250Amps.
The output control R3 at the
maximum position.
CR1 (charge relay) coil voltage.
This low voltage will be present when the protection circuit has determined that the
filter capacitor voltage is
acceptable. Note: The CR1
charge relay should be activated.
This voltage will be present
unit the protection circuit
determines that the filter
capacitor is at an acceptable
level.
Note: The CR1 charge relay
will not be activated.
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Lead #309 (6J6)+
to
lead #310 (3J6)
Lead #311 (4J6)+
to
lead #313 (5J6)-
Lead #311 (4J6)+
to
lead #313 (5J6)-
INVERTEC V250-S
12VDC
0 to 1VDC.
15VDC.
This voltage should be present only after the protection
circuit as been satisfied.
If voltage protection circuit IS
satisfied.
If voltage protection circuit is
NOT satisfied.
Page 62
F-30
NOTES
F-30
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INVERTEC V250-S
Page 63
F-31
TROUBLESHOOTING & REPAIR
CONTROL BOARD VOLTAGE TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
This test will aid the technician in determining if the control board or some other machine
component may be faulty.
MATERIALS NEEDED
Voltmeter/ohmmeter (Multimeter)
Wiring diagram.
Control board schematic drawing.
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INVERTEC V250-S
Page 64
F-32
TROUBLESHOOTING & REPAIR
CONTROL BOARD VOLTAGE TEST (continued)
F-32
1J1
(RED LEAD)
3J1
(RED LEAD)
TEST PROCEDURE
1. Remove main input power to the
V250-S.
2. Perform
Discharge Procedure
Maintenance Section.
3. Locate and familiarize yourself with
the leads and pin locations in plugs
J1 thru J5 on the control board. See
Figure F.9.
J1
Filter Capacitor
detailed in
1J5
(#322)
J2J5J3J4
4J5
(#318)
4. The following tests will be performed
with the input power applied to the
V250-S. BE CAREFUL. ALWAYS
REMOVE INPUT POWER AND
PERFORM FILTER CAPACITOR
DISCHARGE PROCEDURE
BEFORE TOUCHING ANY
MACHINE COMPONENT.
5. Apply input power and turn ON the
V250 -S.
6. Perform the voltage checks outlined
in
Table F.5
. making sure all of the
test conditions are in effect.
1J3
(#375)
7J3
(#303)
(BLACK LEAD)
(WHITE LEAD)
1J4
2J4
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G2666-[ ]
V250S CONTROL
Figure F.9 Plugs J1-J5 on Control Board
INVERTEC V250-S
Page 65
F-33
CONTROL BOARD VOLTAGE TEST (continued)
TEST DESCRIPTION
TROUBLESHOOTING & REPAIR
TABLE F.5. Control Board Voltage Test Points.
ACCEPTABLE
TEST POINTS
VOLTAGES
F-33
TEST CONDITIONS
The 18VAC from the auxiliary transformer to the control board.
Remote trigger circuit test.
(#2 and #4)
Remote trigger circuit test.
(#2 and #4)
Shunt feedback milli-volt
check.
Red lead (1J1)
to
Red lead (3J1)
Lead #318 (4J5)
to
Lead #322 (1J5)
Lead #318 (4J5)
to
Lead #322 (1J5)
White lead (2J4)+
to
Black lead (1J4)-
18VAC
Note: voltage will vary with
input line voltage.
0 VDC.
12VDC.
100 mV.
The correct input voltage
applied to the V250-S and
the input power switch (S1)
in the ON position.
When remote trigger circuit
is “closed”.
When remote trigger circuit
is “open”.
Machine loaded to 120
Amps
Check for 15VDC control
board supply voltage.
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Lead #303 (7J3)+
to
Lead #375 (1J3)-
INVERTEC V250-S
15VDC.
The correct input voltage
applied to the V250-S and
the input power switch (S1)
in the ON position.
Page 66
F-34
NOTES
F-34
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INVERTEC V250-S
Page 67
F-35
TROUBLESHOOTING & REPAIR
PROTECTION CIRCUIT TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
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INVERTEC V250-S
Page 68
F-36
TROUBLESHOOTING & REPAIR
PROTECTION CIRCUIT TEST (continued)
F-36
TEST PROCEDURE
1. Remove main input power to the
V250-S.
2. Perform
Procedure
Section.
Filter Capacitor Discharge
detailed in Maintenance
8J2
J1
J2J5J3J4
6J2
1J2
2J2
3. Locate and familiarize yourself with
the leads and pin locations in plug J2
on the control board and also plug
J6 on the power board. See Figures
F.10. and F.11.
G2666-[ ]
V250S CONTROL
Figure F.10 Control Board Plug J2 Test Points
#313 (5J6)
#309 (6J6)
#310 (3J6)
#311 (4J6)
#308 (1J6)
#307 (2J6)
PLUG J6
205
208
209
V250S POWER G2684
J6
204
201
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Figure F.11 Power Board Plug J6 Test Points
INVERTEC V250-S
Page 69
F-37
TROUBLESHOOTING & REPAIR
PROTECTION CIRCUIT TEST (continued)
F-37
4. The following tests will be performed
with the input power applied to the
V250-S. BE CAREFUL. ALWAYS
REMOVE INPUT POWER AND
PERFORM FILTER CAPACITOR
DISCHARGE PROCEDURE
BEFORE TOUCHING ANY
MACHINE COMPONENT.
5. Apply input power and turn ON the
V250-S.
6. Check for 0 to 1 VDC at leads
#311(4J6)+ to #313(5J6)- at the
power board. If the correct voltage
is present go to step #7.
If 15VDC is present the overvoltage
protection circuit has not been satisfied. Perform the
Test
. If the capacitor balance is
Capacitor Balance
good and the overvoltage protection
circuit has NOT been satisfied the
power board may be faulty. Replace.
7. Check for 0 to 1VDC at leads
#311(2J2)+ to #313(8J2)- at the control board. If the correct voltage is
present go to step 8.
If the correct voltage is present at
the power board but not at the control
board check associated leads and
connections.
8. Check for 15VDC at leads
#309(1J2)+ to #310(6J2)- at the control board. If the correct voltage is
present check for 15VDC at leads
#309(6J6) + to #310(3J6)- at the
power board.
If the correct voltage is present at the
control board but not at the power
board check the associated leads
and connections.
If the correct voltage, 15VDC, is not
present at the control board the control board may be faulty. Perform the
Control Board Voltage Test
.
9. If 15VDC IS present at leads
#309(6J6)+ to #310(3J6)- at the
power board the input relay
(1CR), should activate (pull-in) and
apply full input power to the filter
capacitors.
If this does not take place the power
board may be faulty. Replace.
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POWER BOARD
O
D
V
E
E
T
R
E
V
C
O
T
L
I
T
O
A
N
G
E
1CR
CHARGE
RELAY
PROTECTION CIRCUIT (SIMPLIFIED)
TIMER
(4J6)
)
5J6(
(6J6)
(3J6)
INVERTEC V250-S
#311
#313
#309
#310
(2J2)
(8J2)
(1J2)
(6J2)
CONTROL BOARD
+15VDC
+15VDC
Page 70
F-38
NOTES
F-38
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INVERTEC V250-S
Page 71
F-39
TROUBLESHOOTING & REPAIR
CAPACITOR BALANCE TEST
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
This test will help the technician to determine if the input filter capacitors are being charged
equally and to the correct voltage levels. Note: This test should only be conducted with the
V250-S reconnect switch and “A” jumper configured for 380VAC and above.
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INVERTEC V250-S
Page 72
F-40
TROUBLESHOOTING & REPAIR
CAPACITOR BALANCE TEST (continued)
F-40
TEST PROCEDURE
1. Remove main input power to the
V250-S.
2. Perform
Procedure
Section.
3. Put the mode switch S2 in the
SMAW (soft) position and put the
Local/Remote switch S3 in the
LOCAL position.
4. Put the Output Control R3 at the
minimum position.
5. Locate and familiarize yourself with
the capacitor test locations on the
power board. See Figure F.12.
Filter Capacitor Discharge
detailed in Maintenance
6. The following tests will be performed
with the input power applied to the
V250-S.
BE CAREFUL. ALWAYS
REMOVE THE INPUT POWER AND
PERFORM FILTER CAPACITOR
DISCHARGE PROCEDURE
BEFORE TOUCHING ANY
MACHINE COMPONENT.
7. Apply the correct input power†and
turn ON the V250-S.
† Note: This test should only be conducted
with the V250-S reconnect switch and “A”
jumper configured for 380VAC and above.
CAPACITOR (C2) TERMINALS
201
204
V250S POWER G2684
209
208
205
207A
203A
+
202A
DANGER
HIGH VOLTAGE CAN KILL
+
206
CAPACITOR (C1) TERMINALS
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Figure F.12 Power Board and Capacitor Test Locations
INVERTEC V250-S
Page 73
F-41
TROUBLESHOOTING & REPAIR
CAPACITOR BALANCE TEST (continued)
F-41
8. Check for the appropriate voltages
outlined in Table F.6. Note:
Voltages may vary with the input
line voltage.
In the event the capacitor voltage is
too high or not balanced (within
20VDC) the protection circuit will prevent output. The overvoltage trip setting is nominal line voltage (230/460)
+15%. Reset occurs about 3% lower
(230/460) +12%.
9. If the capacitor voltages are NOT
balanced within 20VDC the capacitors may be need “conditioning” .
See
maintenance
The capacitors or other components
on the power board may be faulty.
Replace power board.
EXPECTED VOLTS
DC AT CAPACITOR
section.
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NOTE
The following machine parts must be replaced in matched sets If
Capacitor C1 is found to be defective, both Capacitors C1 and C2
must be replaced at the same time:
INVERTEC V250-S
Page 74
F-42
NOTES
F-42
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INVERTEC V250-S
Page 75
F-43
TROUBLESHOOTING & REPAIR
CONTROL BOARD REMOVAL AND REPLACEMENT
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
Small needle-nose pliers
Small screwdriver
5/16” nut-driver
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INVERTEC V250-S
Page 76
F-44
TROUBLESHOOTING & REPAIR
CONTROL BOARD REMOVAL AND REPLACEMENT (continued)
F-44
PROCEDURE
1. Remove input power to the V250-S.
2. Perform
Procedure
Section.
3. Locate the control board and the five
molex type plugs that are connected
to it. See Figure F.13.
4. Carefully remove the five molex type
plugs by depressing the locking tabs
and gently extracting the plugs from
the P.C. board receptacles.
5. Using the needle nose-pliers and
small screwdriver gently remove the
control board from the six mounting
pins by depressing the tabs on the
mounting pins and sliding the board
from the pins. See Figure F.13.
Filter Capacitor Discharge
detailed in Maintenance
Note: Be sure to observe static electricity precautions when handling
P.C. boards.
6. When replacing the control board
align the mounting holes with the
mounting pins and gently slide the
P.C. board onto the mounting pins
until the board “snaps” onto the
mounting pins.
Note: Be sure to observe static electricity precautions when handling
P.C. boards.
7. Replace the five molex type plugs in
their appropriate receptacles.
8. Inspect, clear and secure all leads in
preparation for case wrap-around
reassembly.
9. Using the 5/16” nut-driver replace
the case wrap-around.
J1
J2J5J3J4
SIX MOUNTING TABS
V250S CONTROL
G2666-[ ]
DEPRESS LOCKING TAB
ON MOUNTING PIN
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Figure F.13 Control Board Plugs and Mounting Pins
INVERTEC V250-S
Page 77
F-45
TROUBLESHOOTING & REPAIR
POWER BOARD REMOVAL AND REPLACEMENT
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
5/16” nut-driver
1/4” nut-driver
7/16” wrench
3/16” Allen type wrench
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INVERTEC V250-S
Page 78
F-46
TROUBLESHOOTING & REPAIR
POWER BOARD REMOVAL AND REPLACEMENT (continued)
F-46
PROCEDURE
1. Remove input power to the V250-S.
2. Perform
Procedure
Section.
3. Locate the power board, the molex
type plug J6, the five leads with
push-on connectors and the four
capacitor leads that are connected to
the power board.
4. Carefully remove leads (with pushon connectors) #201, #204, #205,
#208, and #209 from the power
board.
Filter Capacitor Discharge
detailed in Maintenance
5. Remove plug J6 by depressing the
locking tab and removing it from the
power board.
6. With the 7/16” wrench remove the
four bolts and washers from the filter
capacitor terminals.
Remove leads #202A, #207A,
#203A and #206 from the capacitor
terminals.
See Figure F.14. Cut any necessary cable ties.
201
204
J6
V250S POWER G2684
209
208
207A
203A
+
202A
4 SOCKET HEAD
CAP SCREWS
DANGER
HIGH VOLTAGE CAN KILL
+
206
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205
Figure F.14 Power Board Lead Locations
INVERTEC V250-S
Page 79
F-47
TROUBLESHOOTING & REPAIR
POWER BOARD REMOVAL AND REPLACEMENT (continued)
F-47
7. Using the 1/4” nut-driver remove the
two screws holding the P.C. board to
the heat sink mounting bracket.
8. With the 3/16” Allen wrench remove
the four socket head cap screws and
washers holding the power board to
the large aluminum heat sink.
9. Carefully remove the power board
taking note as to the amount of heat
sink compound used between the
IGBTs and the large aluminum heat
sink. Note: Be sure to observe static
electricity precautions when handling
P.C. boards.
If the filter capacitors are to be
removed see
Removal and Replacement
POWER BOARD REPLACEMENT
PROCEDURE
Filter Capacitor
.
13. Assemble the leads #202A, #207A,
#203A and #206 to their respective
capacitor terminals using the bolts,
lockwashers and 7/16” wrench.
Torque to 50 - 60 IN. Lbs.
14. Using the 1/4” nut-driver install the
two screws holding the P.C. board
to the heat sink mounting bracket.
15. Connect leads #201, #204, #205,
#208, and #209 to their appropriate
terminals.
16. Replace plug J6 into power board.
17. Replace any previously removed
cable ties.
18 Inspect, clear and secure all leads
in preparation for case wrap-around
reassembly.
10. Apply a thin coat of Dow Corning
340 heat sink compound (Lincoln
E1868) to the filter capacitor terminals. Do not apply to screw threads
or threaded area of terminals.
11. When replacing the power board
apply a thin coating (.005 to .010)
of Dow Corning 340 heat sink
compound (Lincoln E1868) to the
mating surfaces between the
IGBTs and the aluminum heat
sink. Compound is NOT permitted
on the screw heads or mounting
hole threads. The mating surfaces
must be clean and free of any foreign material.
12. Install the power board and tighten
the four cap head screws. Torque
the cap head screws to 40 to 48 IN.
Lbs. Note: Before tightening make
certain the capacitor terminals are
aligned with their respective holes
in the power P.C. board.
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INVERTEC V250-S
Page 80
F-48
NOTES
F-48
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INVERTEC V250-S
Page 81
F-49
TROUBLESHOOTING & REPAIR
FILTER CAPACITOR REMOVAL AND REPLACEMENT
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
The following machine parts must be replaced in matched sets If Capacitor C1 is found to be
defective, both Capacitors C1 and C2 must be replaced at the same time:
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INVERTEC V250-S
Page 82
F-50
TROUBLESHOOTING & REPAIR
FILTER CAPACITOR REMOVAL AND REPLACEMENT (continued)
F-50
PROCEDURE
1. Remove input power to the V250-S.
2. Perform
Procedure
Section.
3 . Perform
Procedure
4. Using the 5/16’ nut-driver remove
the two screws from the top rear of
the case back. See Figure F.15.
Filter Capacitor Discharge
detailed in Maintenance
Power Board Removal
in this section.
5. Using the 5/16” nut-driver remove
the two screws from the top front of
the case front panel. See Figure
F.15.
6. Using the slot head screwdriver
carefully disengage the
heatsink/power board mounting
bracket from the top center panel.
This can be accomplished by sliding
the bracket assembly towards the
rear of the machine while at the
some time gently lifting up on the top
center panel. See Figure F.15.
REMOVE
CASE FRONT
SCREWS
TOP CENTER PANEL
MOUNTING BRACKETS
REMOVE
CASE BACK
SCREWS
POWER BOARD
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Figure F.15 Heatsink/Power Board Removal
INVERTEC V250-S
Page 83
F-51
TROUBLESHOOTING & REPAIR
FILTER CAPACITOR REMOVAL AND REPLACEMENT (continued)
7. Once the top of the bracket assembly is disengaged from the top center
panel the bracket assembly can be
removed from the bottom of the case
by sliding the bracket assembly
towards the front of the machine.
The locking tab on the bottom of the
bracket will have to be lifted slightly
to enable the assembly to slide
freely towards the front.
8. With the bracket assembly out of the
machine the filter capacitors can be
removed by loosening the capacitor
clamps and sliding the filter capacitors out of the assembly.
Note: Before removing the capacitors precisely mark where the capacitors are positioned in the clamp.
This is important so the new capacitor terminals will align with the holes
in the power board. Also mark
polarity configuration for
reassembly purposes.
9. Install the new capacitors taking note
of position in the clamp and also
polarity location.
10. Using the slot head screwdriver
tighten the clamps.
11. Install the heatsink/power board
bracket assembly (with new capacitors installed) into the
machine by first positioning the
bottom of the bracket into the slots
in the case bottom and sliding the
bracket assembly towards the rear
of the machine.
12. Carefully position the top of the
heatsink/power board bracket
assembly into the top center panel
and slide the panel towards the
rear of the machine while holding
the heatsink/power board mounting
bracket in place.
13. Using the 5/16’ nut-driver replace
the two screws at the top rear of
the case back. See Figure F.15.
14. Using the 5/16” nut-driver replace
the two screws at the top front of
the case front panel. See Figure
F.15.
15. Perform
Replacement Procedure
section.
Power Board
in this
F-51
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INVERTEC V250-S
Page 84
F-52
NOTES
F-52
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INVERTEC V250-S
Page 85
F-53
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
3/16” Allen type wrench
Phillips head screwdriver
7/16” Box wrench
Torque wrench
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INVERTEC V250-S
Page 86
F-54
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT (continued)
F-54
PROCEDURE
1. Remove input power to the V250-S.
2. Perform
Procedure
Section.
3. Locate the input rectifier and the
leads connected to it. See Figure
F.16.
4. Identify and mark the leads connected to the rectifier terminals.
Filter Capacitor Discharge
detailed in Maintenance
CAP HEAD
MOUNTING
SCREWS
5. With the Phillips head screwdriver
remove the eight leads connected to
the rectifier terminals.
6. Using the 3/16” Allen wrench and
7/16” box wrench remove the two
cap head screws, washers and nuts
mounting the input rectifier bridge to
the center panel assembly.
#207
#207A
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A
B
C
#209
Figure F.16 Input Rectifier Lead Locations
INVERTEC V250-S
Page 87
F-55
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT (continued)
7. Carefully remove the input rectifier
bridge.
8. When installing a new input rectifier
apply a thin coating of Dow Corning
340 Heat Sink Compound (Lincoln
E1868) to the mating surfaces.
Torque the mounting cap screws
and nuts to 44 IN-LBS.
9. Reconnect the eight leads to the correct terminals and torque the phillips
head screws to 31 IN-LBS.
F-55
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INVERTEC V250-S
Page 88
F-56
NOTES
F-56
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INVERTEC V250-S
Page 89
F-57
TROUBLESHOOTING & REPAIR
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT
(MACHINE CODES BELOW 10150)
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
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INVERTEC V250-S
Page 90
F-58
TROUBLESHOOTING & REPAIR
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT
(MACHINE CODES BELOW 10150)
(continued)
F-58
PROCEDURE
1. Remove input power to the V250-S.
2. Perform
Procedure
Section.
3. Locate output diode assembly and
associated leads. See Figure F.17.
4. Cut the necessary wire ties and slide
the sleeving from the four wire connections to be disassembled. See
Figure F.17
5. Label the leads for identification purposes for reassembly.
Filter Capacitor Discharge
detailed in Maintenance
6. Using the 7/16” wrench remove the
bolts, nuts and washers from two of
the splices.
7. Using the 3/8” wrench and slot head
screwdriver disassemble the other
two splices.
8. Using the 7/16” wrench remove the
bolt and washers connecting the output cable to the diode heat sink. Be
sure to take note of the small resistor
connection at the same point. See
Figure F.17.
9. With the 5/16” nut-driver remove the
two screws from the top rear case
back. See
Figure F.15
.
SNUBBER RESISTORS
7/16 BOLT
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SLEEVED SPLICES
Figure F.17 Output Diode Assembly and Leads
INVERTEC V250-S
Page 91
F-59
TROUBLESHOOTING & REPAIR
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT
(MACHINE CODES BELOW 10150)
(continued)
LOCKING TABS
F-59
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Figure F.18 Heatsink Removal
10. Using the slot head screwdriver
carefully disengage the output
diode heat sink mounting bracket
from the top center panel. Also disengage the bottom heat sink
mounting bracket from the support
bracket. This can be accomplished
by lifting the locking tab and sliding
the heat sink assembly towards the
rear of the machine. See Figure
F.18.
11. Carefully remove the output diode
assembly from the V250-S.
12. Remove the two heat sink holders
from the heat sink/diode assembly.
13. Assemble the two heat sink holders
to the new heat sink/diode assembly.
14. Install the new output diode assembly into position and slide it towards
the front of the machine until the
locking tabs (both top and bottom)
are engaged. See Figure F.18.
INVERTEC V250-S
15. Install the two screws into the top
rear case back. See
16 Using the 7/16” wrench, bolt and
washers connect the output cable to
the diode heat sink. Be sure to take
note of the small resistor connection
at the same point. See
F.17
.
17. Using the 7/16” wrench, bolts, nuts
and washers assemble and tighten
the two splices.
18. Using the 3/8” wrench and slot
head screwdriver assemble and
tighten the other two splices.
19. Position sleeving and secure with
cable ties. Clear all leads and prepare unit for reassembly of wraparound case.
Figure F.15
Figure
.
Page 92
F-60
NOTES
F-60
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INVERTEC V250-S
Page 93
F-61
TROUBLESHOOTING & REPAIR
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT
(MACHINE CODES ABOVE 10150)
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
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INVERTEC V250-S
Page 94
F-62
TROUBLESHOOTING & REPAIR
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT
(MACHINE CODES ABOVE 10150)
(continued)
F-62
PROCEDURE
1. Remove input power to the V250-S.
2. Perform
Procedure
Section.
3. Locate output diode assembly and
associated leads. See Figure F.19.
4. Label the leads for identification purposes for reassembly.
Filter Capacitor Discharge
detailed in Maintenance
7/16 MOUNTING BOLTS
5. Using the 7/16” wrench remove the
bolts, nuts and washers from the
lead terminals of the module to be
replaced. Clear leads and take careful note of lead placement.
DIODE MODULES
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7/16 BOLTED CONNECTIONS
Figure F.19 Output Diode Assembly and Leads
INVERTEC V250-S
Page 95
F-63
TROUBLESHOOTING & REPAIR
OUTPUT DIODE ASSEMBLY REMOVAL AND REPLACEMENT
(MACHINE CODES ABOVE 10150)
(continued)
F-63
6. Using 7/16” wrench remove the top
and bottom mounting bolts and
associated washers from the diode
module to be replaced.
7. Using 1/8” Allen wrench remove the
center socket head cap screw from
the diode module to be replaced.
8. Carefully remove the diode module.
9. To install the new module first make
sure the heat sink surface is clean
and free of dirt.
10. Apply a thin even coating (.004 to
.010 IN.) of thermal compound
Penetrox A13 (Lincoln E2529) to
the bottom surface of the base
plate. Keep the compound away
from the mounting hole areas.
11. Apply a small amount of Loctite
#271 (Lincoln E1777-1) to the first
three threads of the socket head
cap screw.
13. Run the center cap screw in by
hand until it makes contact with the
surface of the module. Do not
torque down yet!
14. Tighten the top and bottom screws
to between 5.0 and 10.0 IN-LBS.
15. Tighten the center cap screw to
between 12 and 18 IN-LBS.
16. Further tighten the top and bottom
screws to between 30 and 40
IN-LBS.
17. Connect the leads to the proper terminals and tighten the screws to
between 30 to 40 IN-LBS. Do not
stress the module terminals when
making these connections.
18. Clear all leads and prepare unit for
reassembly of wrap-around case.
12. Start threading the top and bottom
screws and associated washers by
hand. Also start the center socket
head cap screw and associated
washer.
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INVERTEC V250-S
Page 96
F-64
NOTES
F-64
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INVERTEC V250-S
Page 97
F-65
TROUBLESHOOTING & REPAIR
MAIN TRANSFORMER REMOVAL AND REPLACEMENT
(MACHINE CODES BELOW 10150)
WARNING
Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
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INVERTEC V250-S
Page 98
F-66
TROUBLESHOOTING & REPAIR
MAIN TRANSFORMER REMOVAL AND REPLACEMENT
(MACHINE CODES BELOW 10150)
(continued)
F-66
PROCEDURE
1. Remove input power to the V250-S.
2. Perform
Procedure
Section.
3. Locate main transformer and associ-
ated primary leads. See Figure F.20.
4. Disconnect transformer primary
leads #201, #204, #205 and #208
from the power board.
Note: Leads #204 and #205 will
have to be removed from the T3 current transformer. Cut any necessary
Filter Capacitor Discharge
detailed in Maintenance
cable ties. Be sure to note the
direction that the leads are threaded through the current transformer. Upon reassembly the
leads must be threaded through
correctly.
5. Locate main transformer and associated secondary leads, reactor leads,
and shunt connections. See Figure
F.21.
201
204
T3 CURRENT TRANSFORMER
MAIN TRANSFORMER
208
205
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Figure F.20 Main Transformer Right Side
INVERTEC V250-S
Page 99
F-67
TROUBLESHOOTING & REPAIR
MAIN TRANSFORMER REMOVAL AND REPLACEMENT
(MACHINE CODES BELOW 10150)
(continued)
F-67
MAIN TRANSFORMER
SECONDARY LEADS
Figure F.21 Main Transformer Left Side
6. Disconnect and clear the shunt
sensing leads from the control board
(plug J4).
7. Disconnect the thermostat leads
from the thermostat mounted on the
shunt assembly.
8. With the 3/4” wrench remove the
shunt assembly from the negative
output terminal. Take note of the bypass connection on the negative terminal. Clear the shunt to allow
access to the main transformer and
lead connections. Cut any necessary cable ties.
9. With the 3/4” wrench remove the two
secondary leads from the positive
output terminal. Take note of the bypass connection on the positive terminal.
10. Locate and cut the necessary wire
ties and slide the sleeving from the
four transformer secondary and
reactor lead splices.
11. With slot head screwdriver and 3/8”
nut-driver remove the two reactor
leads from output rectifier leads.
Label the leads for reassembly.
12. Using the 7/16” wrench remove the
secondary leads from the output
rectifier leads.
Label the leads and note washer
and lead placement for reassembly.
13. With 3/8” wrench remove the two
screws mounting the transformer
assembly to the base of the
machine. See
The machine will have to be tilted
on its side to gain access to the
bottom of the unit.
Figure F.22
. Note:
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INVERTEC V250-S
Page 100
F-68
TROUBLESHOOTING & REPAIR
MAIN TRANSFORMER REMOVAL AND REPLACEMENT
(MACHINE CODES BELOW 10150)
(continued)
MAIN TRANSFORMER
LOCKING MOUNTING TABS
F-68
MAIN TRANSFORMER
MOUNTING SCREWS
Figure F.22 Main Transformer Mountings
14. Using the slot head screwdriver
unclip the locking tabs and slide the
transformer towards the front of the
machine until it is free of the slots in
the bottom of the machine.
Note: The machine will have to be
tilted on its side to gain access to
the bottom of the unit.
15. With the main transformer loose
from the base carefully tilt and
remove the transformer from the
left side of the machine.
16. Install the new transformer by tilting
and carefully positioning it in place
in the slots in the case bottom.
Slide towards the rear of the
machine until the locking tabs are
in place.
Note: The machine will have to be
tilted on its side to gain access to
the bottom of the unit.
18. Using the 7/16” wrench reassemble
the two secondary leads to the output rectifier leads. Note lead and
washer placement and lead labels.
19. Using the slot head screwdriver
and 3/8” nut-driver reassemble the
two reactor leads to the output rectifier leads. Note lead labels.
20. Replace the sleeving on the four
connections and replace the cable
ties.
21. With the 3/4” wrench assemble the
two secondary leads to the positive
output terminal.
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17. With the 3/8” wrench replace the
two transformer mounting screws.
INVERTEC V250-S
Take note of the by-pass connection on the positive output terminal.
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