1. Manuals
  2. Brands
  3. Valley Manuals
  4. Welding System
  5. FABRICATOR 251
  6. Service manual

Valley FABRICATOR 251 Service Manual

Mig welding machine
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
251

Service Manual

FABRICATOR
MIG WELDING MACHINE
Revision: AB
Operating Features:
®
Art # A-08561
Issue Date: August 22, 2008
208
208
230
230
V V
V V
Manual No.: 0-5099
60 60
H
Z

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the FABRICATOR 251 and is the answer not in the manual?

Questions and answers

Summary of Contents for Valley FABRICATOR 251

  • Page 1: Service Manual

    ® FABRICATOR MIG WELDING MACHINE Art # A-08561 Service Manual Revision: AB Issue Date: August 22, 2008 Manual No.: 0-5099 Operating Features: 60 60...
  • Page 3 While the information contained in this Manual represents the Manufacturer's best judgement, the Manufacturer assumes no liability for its use. Fabricator 251 MIG Welding Machine Service Manual Number 0-5099 for: Package System Part Number 100048DVN...

  • Page 4: Table Of Contents

    TABLE OF CONTENTS SECTION 1: SAFETY INSTRUCTIONS AND WARNINGS ............1-1 1.01 Arc Welding Hazards ..................1-1 1.02 Principal Safety Standards ................1-4 1.03 Symbol Chart ....................1-5 1.04 Precautions De Securite En Soudage A L’arc ..........1-6 1.05 Dangers relatifs au soudage à l’arc ..............1-6 1.06 Principales Normes De Securite ..............
  • Page 5 TABLE OF CONTENTS (continued) TABLE OF CONTENTS SECTION 4: OPERATION ................... 4-1 4.01 Power Supply Controls, Indicators and Features ..........4-1 4.02 Weld Mode Selector ..................4-6 4.03 400 Amp Air-Cooled MIG Gun ................ 4-8 4.04 Installing A New Wire Conduit ................ 4-9 4.05 MIG Gun Maintenance ..................
  • Page 6 TABLE OF CONTENTS SECTION 8: CIRCUIT OPERATION ................8-1 8.01 Circuit Operation Of The Control PCB 7977964 ..........8-1 8.02 Circuit Operation Of The MIG Timer PCB 7977965 ......... 8-2 8.03 Circuit Operation Of The Digital Volt/Amp PCB 704883 ........8-2 8.04 Circuit Operation Of The Spool Gun PCB 7978034 .........

  • Page 7: Safety Instructions And Warnings

    SAFETY INSTRUCTIONS FABRICATOR 251 SECTION 1: SAFETY INSTRUCTIONS AND WARNINGS WARNING PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDREN AWAY. PACEMAKER WEARERS KEEP AWAY UNTIL CONSULTING YOUR DOCTOR. DO NOT LOSE THESE INSTRUCTIONS. READ OPERATING/INSTRUCTION MANUAL BEFORE INSTALLING, OPERATING OR SERVICING THIS EQUIPMENT.

  • Page 8: Safety Instructions

    FABRICATOR 251 SAFETY INSTRUCTIONS 3. Use protective screens or barriers to protect others from flash and glare; warn others not to watch the arc. WARNING 4. Wear protective clothing made from durable, flame-resistant material (wool and leather) and foot protection.
  • Page 9 SAFETY INSTRUCTIONS FABRICATOR 251 2. If used in a closed area, vent engine exhaust outside and away from any building air intakes. WARNING WARNING FLYING SPARKS AND HOT METAL can cause injury. Chipping and grinding cause flying metal. As welds cool, they can throw off slag.

  • Page 10: Principal Safety Standards

    FABRICATOR 251 SAFETY INSTRUCTIONS 1.02 Principal Safety Standards Safety in Welding and Cutting, ANSI Standard Z49.1, from American WARNING Welding Society, 550 N.W. LeJeune Rd., Miami, FL 33126. Safety and Health Standards, OSHA 29 CFR 1910, from Superintendent STEAM AND PRESSURIZED HOT COOLANT can burn of Documents, U.S.

  • Page 11: Symbol Chart

    SAFETY INSTRUCTIONS FABRICATOR 251 1.03 Symbol Chart Note that only some of these symbols will appear on your model. Wire Feed Function Single Phase Wire Feed Towards Workpiece With Three Phase Output Voltage Off. Three Phase Static Frequency Converter- Welding Gun...

  • Page 12: Precautions De Securite En Soudage A L'arc

    FABRICATOR 251 SAFETY INSTRUCTIONS 1.04 Precautions De Securite En Soudage A L’arc MISE EN GARDE LE SOUDAGE A L’ARC EST DANGEREUX PROTEGEZ-VOUS, AINSI QUE LES AUTRES, CONTRE LES BLESSURES GRAVES POSSIBLES OU LA MORT. NE LAISSEZ PAS LES ENFANTS S’APPROCHER, NI LES PORTEURS DE STIMULATEUR CARDIAQUE (A MOINS QU’ILS N’AIENT CONSULTE UN MEDECIN). CONSERVEZ CES INSTRUCTIONS.
  • Page 13 SAFETY INSTRUCTIONS FABRICATOR 251 AVERTISSEMENT AVERTISSEMENT LES VAPEURS ET LES FUMEES SONT DANGEREUSES LE RAYONNEMENT DE L’ARC PEUT BRÛLER LES YEUX POUR LA SANTE. ET LA PEAU; LE BRUIT PEUT ENDOMMAGER L’OUIE. Le soudage dégage des vapeurs et des fumées L’arc de soudage produit une chaleur et des rayons...
  • Page 14 FABRICATOR 251 SAFETY INSTRUCTIONS 7. Ne soudez des tôles galvanisées ou plaquées au plomb ou au 1. Portez un écran facial ou des lunettes protectrices cadmium que si les zones à souder ont été grattées à fond, que si approuvées. Des écrans latéraux sont recommandés.

  • Page 15: Principales Normes De Securite

    SAFETY INSTRUCTIONS FABRICATOR 251 4. N’utilisez pas une source de courant de soudage pour charger un accumulateur ou survolter momentanément un véhicule. AVERTISSEMENT 5. Utilisez la polarité correcte (+ et –) de l’accumulateur. LE CARBURANT PEUR CAUSER UN INCENDIE OU UNE EXPLOSION.

  • Page 16: Graphique De Symbole

    FABRICATOR 251 SAFETY INSTRUCTIONS 1.07 Graphique de Symbole Seulement certains de ces symboles apparaîtront sur votre modèle. Déroulement du Fil Sous Tension Mono Phasé Alimentation du Fil Vers la Pièce de Fabrication Hors Tension Trois Phasé Hors Tension Tri-Phase Statique...

  • Page 17: Introduction

    A NOTE offers helpful information concerning certain operating procedures. Additional copies of this manual may be purchased by contacting Valley National Gases at the address and phone number listed in the inside back cover of this manual. Include the Service Manual number and equipment identification numbers.

  • Page 18: General Information

    SERVICE MANUAL 2.04 General Information 2.06 Protective Filter Lenses The Fabricator 251 is a semiautomatic Gas Metal Arc Protective filter lenses are provided to reduce the intensity Welder (GMAW-commonly MIG) with an integrated wire of radiation entering the eye thus filtering out harmful feed unit.

  • Page 19: Duty Cycle

    2.09 Specifications MIG Gun Specifications Gun Catalog Number 43340VNG Gun Type Valley National Gases 400 Amp Gun Cable Length 15 ft (4.5m) Table 2-2: MIG Gun Specifications Wire Drive Specifications Control Circuit Supply...
  • Page 20 FABRICATOR 251 SERVICE MANUAL Fabricator 251 Package System Part Number 100048DVN Power Source Part Number 871987 Power Source Weight 227lb (103kg) Power Source Dimensions HxWxD 32” x 27-3/16” x 36-3/4” (including wheels and cylinder carrier) (813 x 691 x 933mm)

  • Page 21: Included Items

    Work Lead 10ft (3m) Cable Stowage Hooks Regulator/Flow Meter – Argon Mix Gases Valley National Gases air cooled MIG Gun, 400 Amp, 15ft (4.5m) Fitted Feed Roll for .035” - .045” (0.9 – 1.2mm) solid wire Table 2-5: System Contents 2.11 Optional Accessories...
  • Page 22 FABRICATOR 251 SERVICE MANUAL NOTES: August 22, 2008...

  • Page 23: Installation

    In areas, free from moisture and dust. 3.01 Environment In areas, free from oil, steam and corrosive gases. The Fabricator 251 is NOT designed for use in In areas, not subjected to abnormal vibration or shock. environments with increased hazard of electric shock.

  • Page 24: Mains Supply Voltage Requirements

    3.05 Alternative Mains Supply Voltages WARNING The Fabricator 251 input power supply lead should be replaced with leads as specified in Table 3-2 when the Fabricators input power supply voltage is changed. The Power Supply is suitable for use on the following input power supply voltages:...
  • Page 25 3. Remove the blue wires from the current location and insert them into the new voltage location. Secure by tightening the set screw onto the uninsulated portion of the wires. Secure the other voltage set screw as well. 208V connection 230V connection Art # A-07332 Figure 3-1: Voltage Selections for Fabricator 251 (Wired for 230V) August 22, 2008...

  • Page 26: Quick Setup

    CAUTION 8. Fit the Valley National Gases MIG gun and trigger wires through/to the front of the unit. To obtain adequate air flow and cooling for 9. Remove the contact tip from the gun.
  • Page 27 SERVICE MANUAL FABRICATOR 251 Shielding Regulator and Flow Meter “Cracking” Shielding Shielding Shielding Art # A-07278 Stowage Hook Gas Hose Figure 3-2 Gas Cylinder Installation August 22, 2008...
  • Page 28 FABRICATOR 251 SERVICE MANUAL Adjusting Regulator Adjust control knob of regulator to the required flow rate, indicated on gauge dial. (Refer to Figure 3-3) The gas flow rate should be adequate to cover the weld zone to stop weld porosity. Excessive gas flow rates may cause turbulence and weld porosity.

  • Page 29: Attaching The Gun And Cable Assembly To The Power Source

    Assembly to the Power Source The Fabricator 251 is supplied with a Valley National Gases 400 AMP air-cooled gun. This MIG gun is designed with an ergonomic handle and fewer parts to reduce performance problems. It also uses standard readily available Valley National Gases consumable parts.
  • Page 30 FABRICATOR 251 SERVICE MANUAL Front Panel Access Hole Art # 0-7148 Trigger Receptacle Figure 3-5: Route Gun Cable Through Front Panel Access Hole and Connect Trigger Loosen Thumbscrew Art # A-07149 Tighten Thumbscrew Figure 3-6: Mount Gun Cable to Adapter Socket...

  • Page 31: Input And Output Wire Guide Installation

    Input Wire Guide Output Wire Guide Figure 3-7: Wire Guide Installation Installation of all styles of feed rolls for the Fabricator 251 are identical. 3.10 Selection and Installation of Feedrolls WARNING A Feedroll consists of two different sized grooves. As...

  • Page 32: Installing Wire Spool

    FABRICATOR 251 SERVICE MANUAL 3.11 Installing Wire Spool As delivered from the factory, the unit is set for a 33/44 lb. or 12" (300mm) spool. Installation of wire spool 1. Remove Wire Spool Hub Nut by turning counter clock wise (to the left).

  • Page 33: Inserting Wire Into The Feedhead

    SERVICE MANUAL FABRICATOR 251 3.12 Inserting Wire into the Feedhead WARNING ELECTRIC SHOCK CAN KILL! Make certain the input power is disconnected from the power supply before proceeding. Do not reattach the input power until told to do so in these instructions.

  • Page 34: Wirefeeder Drive Roller Pressure Adjustment

    Tension Adjusting knob clockwise. The use of excessive pressure may cause rapid wear of the feed roller, motor shaft and motor bearings. NOTE Genuine Valley National Gases contact tips and liners should be used. Many non-genuine liners use inferior materials which can cause wire feed problems. 3.14 Wire Reel Hub Brake The wire reel hub incorporates a friction brake which is adjusted during manufacture for optimum braking.

  • Page 35: Spool Gun Attachment

    FABRICATOR 251 3.15 Spool Gun Attachment A spool gun can readily be used with the Fabricator 251 power supply. 1. Attach appropriate input gas to the Spool Gun Gas Input Connection on the rear of the unit (refer to Figure. 3-13).

  • Page 36: Polarity Changeover

    FABRICATOR 251 SERVICE MANUAL 3.16 Polarity Changeover WARNING ELECTRIC SHOCK CAN KILL! Make certain the input power is disconnected from the power supply before proceeding. Do not reattach the input power until told to do so in these instructions. The output terminals are located on the front panel of the welding power source.
  • Page 37 SERVICE MANUAL FABRICATOR 251 Work Lead Connected for D.C. Electrode Negative (DCEN) Welding Art # A-07164 Figure 3-15: Polarity Connections for DCEN Changing polarity process. a. Locate the two terminal knobs at the front of the machine. Refer to Figures 3-14 and 3-15.
  • Page 38 FABRICATOR 251 SERVICE MANUAL NOTES: 3-16 August 22, 2008...

  • Page 39: Operation

    SERVICE MANUAL FABRICATOR 251 SECTION 4: OPERATION WARNING DO NOT TOUCH the electrode wire while it is being fed through the system. The electrode wire will be at welding voltage potential. 4.01 Power Supply Controls, Indicators and Features Thermal Overload Indicator...
  • Page 40 On / Standby Power Switch The indicator light is provided to indicate when the Fabricator 251 is connected to the Input Power Supply Voltage. With the switch in the Standby position, the auxiliary power and the fan are turned off and the switch is illuminated.
  • Page 41 SERVICE MANUAL FABRICATOR 251 Digital AMP Reading to IPM Conversion STEEL Current (Amps) Art # A-07451 Figure 4-3: Steel - AMP to IPM Conversion STAINLESS STEEL Current (Amps) Art # A-07452 Figure 4-4: Stainless Steel - AMP to IPM Conversion...
  • Page 42 FABRICATOR 251 SERVICE MANUAL ALUMINUM Current (Amps) Art # A-07453 Figure 4-5: Aluminum - AMP to IPM Conversion Thermal Overload The critical components for thermal protection are the rectifier stack and the transformer, which are fitted with thermal overload cut out devices. If the overload is activated then the machine should be left to cool for approximately 15 minutes before resuming welding.
  • Page 43 The Spool Gun Interface 10 pin connector is used to the bottom of the unit are shown without the terminal connect a spool gun to the Fabricator 251 (refer to knob. Both knobs must be firmly secured before Figure 4-7 and Table 4-1).

  • Page 44: Weld Mode Selector

    FABRICATOR 251 SERVICE MANUAL 4.02 Weld Mode Selector The Weld Mode Selector switch selects the method of welding mode. WELD WELD DWELL DWELL WELD MODE WELD MODE (STITCH) (STITCH) (SPOT / STITCH) (SPOT / STITCH) STITCH STITCH SPOT SPOT 4T 4T...
  • Page 45 SERVICE MANUAL FABRICATOR 251 STITCH: Dwell Stitch This mode of welding is used to weld two or more DWELL (STITCH) CONTROL KNOB components together with a stitch weld. The WELD When the Weld Mode control is in the Stitch position, the (Spot/Stitch) shaft controls the welding or ‘ON’...

  • Page 46: Amp Air-Cooled Mig Gun

    SERVICE MANUAL 4.03 400 Amp Air-Cooled MIG Gun The Valley National Gases air-cooled 43340VNG 400 amp MIG gun fitted to the FABRICATOR 251 offers robust construction, unparalleled reliability and easy replacement of consumable parts. The Air-Cooled MIG Gun has an operating capacity in excess of the capacity of the FABRICATOR and can be expected to give trouble free service.

  • Page 47: Installing A New Wire Conduit

    SERVICE MANUAL FABRICATOR 251 4.04 Installing A New Wire Conduit 1. Be sure the MIG gun cable is arranged in a straight line, free from twists, when installing or removing a wire conduit. Remove the old conduit by first removing the MIG gun nozzle, contact tip, insulator and gas diffuser.

  • Page 48: Mig Gun Maintenance

    Setting of the Power Supply The setting of the Fabricator 251 requires some practice by the operator, in that the welding power supply has two control settings that have to balance. These are the Wire Speed Control and the Voltage Control Switches. The welding current is determined by the Wire Speed Control, the current will increase with increased Wire Speed, resulting in a shorter arc.
  • Page 49 SERVICE MANUAL FABRICATOR 251 Solid Wire Flux Cored Wire Art # A-07186 3/8” (9.5mm) 5/16” (7.9mm) 1/4” (6.4mm) 11/16” Distance: ± 1/16” 9/16” (17.5mm) (14.3mm) .023” .030” .035” (.6mm) (.8mm) (.9mm) .035” .045” Wire Diameter (.9mm) (1.1mm) Figure 4-19: Optimum Contact Tip to Work Distances...

  • Page 50: Stitch Welding Operation

    SPOT WELDING NOZZLES for consistent spot welding operations. Refer to the TYPE NO.4 400 AMP Spot Welding Nozzle table. The Fabricator 251 will operate effectively using .030” (0.8mm) electrode wire when spot welding. Penetration depth is limited Flat Arc Spot 24A-62-FAS 1240-1520 (5/8"...

  • Page 51: Gas Selection For Gas Metal Arc Welding

    SERVICE MANUAL FABRICATOR 251 4.09 Gas Selection for Gas Metal Arc Welding Suggested Base Plate Filler Transfer Welding Metal Type Shielding Comments Thickness Metal Mode Positions Carbon Greater than 22 ER70S-X Short High welding speeds. Good 100% CO Steel gauge (.030”)

  • Page 52: Welding Setting Selection Guide

    FABRICATOR 251 SERVICE MANUAL 4.10 Welding Setting Selection Guide Shielding Gas Wire Size Material Type Wire Type (Diameter) and Flow Rate .035” (0.9mm) 100% CO 25cfh .045” (1.2mm) .023” (0.6mm) .030” (0.8mm) 75% Ar 25% ,25cfh Solid .035” (0.9mm) (or hard) Steel .045”...
  • Page 53 SERVICE MANUAL FABRICATOR 251 Coarse Voltage THICKNESS Fine Voltage Step Wire Coarse Fine Speed Voltage Voltage 22 ga. (0.8mm) 18 ga. (1.2mm) 16 ga. (1.6mm) 1/8” (3.2mm) 1/4” (6.4mm) 3/8” (9.5mm) 1/2” (12.7mm) 5/8” (15.9mm) 7.25 1.75 4.25 2.25 5.25 8.25...
  • Page 54 FABRICATOR 251 SERVICE MANUAL NOTES 4-16 August 22, 2008...

  • Page 55: Maintenance

    SECTION 5: MAINTENANCE 5.01 Routine Maintenance & Inspection The only routine maintenance required for the Fabricator 251 is a thorough cleaning and inspection, with the frequency depending on the usage and the operating environment. WARNING Disconnect the Fabricator from the Input power supply voltage before disassembling.
  • Page 56 FABRICATOR 251 SERVICE MANUAL Maintain more often Warning! if used under severe Disconnect input power before maintaining. conditions Each Use Visual check of torch Visual check of Consumable parts regulator and pressure Weekly Visually inspect the torch Visually inspect the body and consumables cables and leads.

  • Page 57: Basic Troubleshooting

    The basic level of troubleshooting is that which can be performed without special equipment or knowledge, and without removing the covers from the Power Supply. If major components are faulty, then the Power Supply should be returned to an Accredited Valley National Gases Service Agent for repair.

  • Page 58: Solving Problems Beyond The Welding Terminals

    3. Internal gas hose in or disconnected from the MIG torch the power supply adaptor. Return to an Accredited Valley National Gases Service Agent for repair. 4. Welding in a windy a. Shield the weld area from the wind or...
  • Page 59 SERVICE MANUAL FABRICATOR 251 2. Inconsistent wire feed FAULT CAUSE REMEDY 1. Wire spool brake is a. Feed roll driven by motor in the cabinet will slip. too tight. 2. Wire spool brake is a. Wire spool can unwind and tangle too loose.

  • Page 60: Welding Problems

    FABRICATOR 251 SERVICE MANUAL 6.03 Welding Problems FAULT CAUSE REMEDY 1. Welding arc voltage a. Reduce voltage by reducing the voltage too high. selection switch position or increase the wire feed speed. A. Undercut 2. Incorrect torch a. Adjust angle angle 3.
  • Page 61 6. Weld speed too fast a. Reduce weld speed. 1. Faulty rectifier unit a. Have an Accredited Valley National Gases Service Agent to test then replace the faulty component. B. Cold weld puddle 2. Loose welding cable a.

  • Page 62: Power Supply Problems

    B. Primary power supply voltage 1. Primary fuse is blown. a. Replace primary fuse. is ON. Indicator light is not lit 2. Broken connection in a. Have an Accredited Valley and welding arc can not be primary circuit. National Gases Service Agent established.

  • Page 63: Advanced Troubleshooting

    SERVICE MANUAL FABRICATOR 251 SECTION 7: ADVANCED TROUBLESHOOTING If the problem cannot be solved by the basic (external) trouble shooting guide, the Power Source covers and/or the Wire Feeder covers will have to be removed. The advanced level of troubleshooting allows the technician with a few common tools to remove the covers and analyze failures.

  • Page 64: Initial Setup Conditions

    FABRICATOR 251 SERVICE MANUAL 7.02 Initial Setup Conditions 7.03 Primary Power Test Set the power supply controls and connect cables as A. Close primary disconnect device and observe the follows: following: 1. ON/OFF Switch to OFF Position 1. Green Indictor Lamp inside ON/OFF Switch illuminates 2.

  • Page 65: Logic And Control Tests

    SERVICE MANUAL FABRICATOR 251 7.04 Logic and Control Tests G. Release Gun Switch 1. Feed Roll stops immediately A. Depress Gun Switch and observe the following: 2. Display reads "15.0 V" 1. Gas flows 2. After 1 ½ seconds 2. Contactor energizes a.

  • Page 66: Spool Gun Control (J1) Test

    FABRICATOR 251 SERVICE MANUAL J. Set MODE SELECTOR SWITCH to STITCH position. O. Set WIRE SPEED CONTROL to "4" Set WELD (SPOT/STITCH) TIMER CONTROL to P. Set COARSE VOLTAGE SELECTOR SWITCH to minimum. position "L". 1. Depress Gun Switch Q. Set FINE VOLTAGE SELECTOR SWITCH to position "1".

  • Page 67: Output Voltage Test

    SERVICE MANUAL FABRICATOR 251 7.06 Output Voltage Test A. Set COARSE VOLTAGE SELECTOR SWITCH to position "L" B. Set FINE VOLTAGE SELECTOR SWITCH to position "1" C. Connect voltmeter probes to + & - WELDING TERMINALS D. Depress Gun Switch and observe voltage E.

  • Page 68: Wire Feed & Weld Test

    FABRICATOR 251 SERVICE MANUAL 7.07 Wire Feed & Weld Test 7.08 Primary Power Problems A. Close the PRESSURE ADJUST DEVICE. Connect the GUN A. Green Indicator in ON/OFF Switch is not POLARITY LEAD to the POSITIVE WELDING TERMINAL illuminated and fan does turn when ON/OFF (+).

  • Page 69: Logic And Control Problems

    SERVICE MANUAL FABRICATOR 251 8. Faulty MAIN PCB 1 7.09 Logic and Control Problems a. Measure between JB-4 to JB-11 at PCB 1 for A. Nothing happens when gun switch is depressed; approx 30 VAC when gun switch is closed. If No gas flow, contactor does not energize, feed voltage is not present, replace PCB.

  • Page 70: Spool Gun Control (J1) Problem

    FABRICATOR 251 SERVICE MANUAL 3. Open wire from Rectifier assembly to Control PCB. 7.10 Spool Gun Control (J1) Problem a. With gun switch closed, measure for approx A. Gas does not flow when jumper is connected 15 VDC at Control PCB between JB7 (-) to JB9 between J11 Pins D &...

  • Page 71: Wire Feed And Weld Problems

    SERVICE MANUAL FABRICATOR 251 7.12 Wire Feed and Weld Problems A. Poor or inconsistent arc transfer or no arc transfer 1. Poor work cable connection or open work cable a. Clean contact point, check continuity of cable and cable to clamp connection. Replace if work cable if required.

  • Page 72: Sw3 Coarse And Sw4 Fine Rotary Switch Test

    FABRICATOR 251 SERVICE MANUAL 7.14 SW3 Coarse and SW4 Fine Rotary Switch Test WIRE No'S. TERMINAL No'S. TOP OF SWITCH TERMINAL No'S. WIRE No'S. Art # A-08568 WIRE No'S. TERMINAL No'S. BOTTOM OF SWITCH TERMINAL No'S. WIRE No'S. Figure7-2: 3-Position Rotary Switch, Coarse WIRE No'S.
  • Page 73 SERVICE MANUAL FABRICATOR 251 VOLTAGE CONTROL SWITCH TEST One at a time remove SW-3 and SW-4 from front panel, disconnect wires, reconnect to panel and check continuity of switch per figure 7-5. Art # A-08571 Set Screw Knob Retainer Locking Collar...

  • Page 74: Mig Timer Pcb (Pcb2) Test

    FABRICATOR 251 SERVICE MANUAL 7.15 MIG Timer PCB (PCB2) Test Using the MAIN PCB terminal JB-5 as common measure the voltage at JD-1. This should measure 20VDC when the Gun Switch is closed. Then measure the voltage at JD-2. WELD MODE SELECTOR WITCH...

  • Page 75: Rectifier Assembly Test

    SERVICE MANUAL FABRICATOR 251 7.16 Rectifier Assembly Test 1. Disconnect one of the Main Transformer connections from the rectifier assembly. 2. Disconnect and isolate wires from the Negative output of the Rectifier Assembly See Figure 7-3. 3. Disconnect JB connector from MAIN PCB 1.

  • Page 76: Main Transformer Test

    FABRICATOR 251 SERVICE MANUAL 7.17 Main Transformer Test Disconnect the secondary of the Main Transformer T2 from the rectifier bridge and measure output voltage between the two transformer output connections as follows: COARSE VOLTAGE SELECTION FINE VOLTAGE SELECTOR VOLTAGE AC (approx.)

  • Page 77: Circuit Operation

    SERVICE MANUAL FABRICATOR 251 SECTION 8: CIRCUIT OPERATION 8.01 Circuit Operation Of The Control PCB 7977964 Power Supply 24VAC is taken from the auxiliary wiring of the fan. This voltage is then connected to the PCB 7977964 where it is half wave rectified and filtered.

  • Page 78: Circuit Operation Of The Digital Volt/Amp Pcb 704883

    FABRICATOR 251 SERVICE MANUAL CONNECTOR JB 8.02 Circuit Operation Of The MIG Timer PCB 7977965 Terminal JB-1 wiper of wire speed control potentiometer, This board is connected by way of a 6-way cable and varies between <2V to approximately 4.7VDC does not have any terminals available to measure.

  • Page 79: Circuit Operation Of The Spool Gun Pcb 7978034

    SERVICE MANUAL FABRICATOR 251 8.04 Circuit Operation Of The Spool Gun Terminal X2/4 trigger relay - connects to trigger input of PCB 7978034 7977964 PCB CONNECTOR X1 Terminal X2/5 trigger relay - connects to trigger input of Terminal X1/1 7977964 PCB motor relay "normally open"...
  • Page 80 FABRICATOR 251 SERVICE MANUAL NOTES: August 22, 2008...

  • Page 81: Parts List

    SERVICE MANUAL FABRICATOR 251 SECTION 9: PARTS LIST 9.01 Equipment Identification All identification numbers as described in the Introduction chapter must be furnished when ordering parts or making inquiries. This information is usually found on the nameplate attached to the equipment. Be sure to include any dash numbers following the Part or Assembly numbers.

  • Page 82: External Replacement Parts

    FABRICATOR 251 SERVICE MANUAL 9.03 External Replacement Parts ITEM ITEM ITEM ITEM ITEM P P P P P AR ART NUMBER T NUMBER T NUMBER T NUMBER T NUMBER DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION REF DESIGNA REF DESIGNA REF DESIGNA...
  • Page 83 SERVICE MANUAL FABRICATOR 251 4, 22 Art # A-08572 23, 24 August 22, 2008...

  • Page 84: Internal Replacement Parts (1)

    FABRICATOR 251 SERVICE MANUAL 9.04 Internal Replacement Parts (1) ITEM ITEM ITEM ITEM ITEM P P P P P AR ART NUMBER T NUMBER T NUMBER T NUMBER T NUMBER DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION REF DESIGNA REF DESIGNA REF DESIGNA...
  • Page 85 SERVICE MANUAL FABRICATOR 251 Art # A-07516 August 22, 2008...

  • Page 86: Major Electrical And Mechanical Replacement Parts

    FABRICATOR 251 SERVICE MANUAL 9.05 Major Electrical and Mechanical Replacement Parts ITEM ITEM ITEM ITEM ITEM P P P P P AR ART NUMBER T NUMBER T NUMBER T NUMBER T NUMBER DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION REF DESIGNA REF DESIGNA...

  • Page 87: Internal Replacement Parts (2)

    SERVICE MANUAL FABRICATOR 251 9.06 Internal Replacement Parts (2) ITEM ITEM ITEM ITEM ITEM P P P P P AR ART NUMBER T NUMBER T NUMBER T NUMBER T NUMBER DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION REF DESIGNA REF DESIGNA REF DESIGNA...

  • Page 88: Internal Replacement Parts-Spool Assembly

    FABRICATOR 251 SERVICE MANUAL 9.07 Internal Replacement Parts-Spool Assembly ITEM ITEM ITEM ITEM ITEM P P P P P AR ART NUMBER T NUMBER T NUMBER T NUMBER T NUMBER DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION See Note Screw, Hex HD, 3/8"-16x3/4",STZP...

  • Page 89: Internal Replacement Parts-Wire Feeder

    SERVICE MANUAL FABRICATOR 251 9.08 Internal Replacement Parts-Wire Feeder ITEM ITEM ITEM ITEM ITEM P P P P P AR ART NUMBER T NUMBER T NUMBER T NUMBER T NUMBER DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION DESCRIPTION Feed rolls and guides may be found in the Feed Roll kit located in the Appendix section of this manual.

  • Page 90: Wire Feeder Replacement Parts

    FABRICATOR 251 SERVICE MANUAL 9.09 Wire Feeder Replacement Parts Item Item Item Qty Item Item Qty Ref Ref. Des. . Des. . Des. . Des. . Des. Description Description Description Description Description Part Number Part Number Part Number Part Number...

  • Page 91: Appendix 1: Feedroll Kits

    FABRICATOR 251 APPENDIX 1: FEEDROLL KITS FEED ROLL KITS (#375980-Series) 2 ROLL Style 1 Style 2 Style 3 Style 4 Style 5 Style 6 Double Smooth Double Flat Flat Knurled "V" Knurled "V" Double Cog Double "U" Double Double Double Smooth...

  • Page 92: Appendix 2: Power Supply Circuit Diagram

    FABRICATOR 251 APPENDIX 2: POWER SUPPLY CIRCUIT DIAGRAM • Note the model number shown on the equipment nameplate 4 BLUE COARSE 4A BLUE 8&8A BRN FABRICATOR 251 (10) 8 BRN 9&9A BLK (12) (11) 9 BLK 10&10A RED Input Ter minal Block...
  • Page 93 FABRICATOR 251 SWITCH 2 COARSE SWITCH 3 FI NE SWI TCH POSITI ON POSITI ON 10 12 10 12 Bridge Recti fier POSITIVE OUTPUT Induct or TERMINAL PLUGSOCKET 21 ORN X1/6 PCB 4 22 VIO Varis tor X1/5 + C1-C4...

  • Page 94: Appendix 3: Main Pcb Circuit Diagram

    FABRICATOR 251 APPENDIX 3: MAIN PCB CIRCUIT DIAGRAM 30 VAC Art # A-08574 August 22, 2008...
  • Page 95 FABRICATOR 251 DESCRIPTION: FABRICATOR MAIN PCB 7977964 Art # A-08574 August 22, 2008...

  • Page 96: Appendix 4: Spot Timer Circuit Diagram

    FABRICATOR 251 APPENDIX 4: SPOT TIMER CIRCUIT DIAGRAM Art # A-08575 August 22, 2008...
  • Page 97 FABRICATOR 251 DESCRIPTION: FABRICATOR SPOT TIMER 7977965 CODE DESIGN: Art # A-08575 August 22, 2008...

  • Page 98: Appendix 5: Spool Gun Pcb

    FABRICATOR 251 APPENDIX 5: SPOOL GUN PCB +14Vdc +35Vdc +14Vdc 1N4004 100n +Vout 1N4004 1N4004 LM317T 270R 22u 50V 100n 100n 470u 50V 4013 1N4004 1N4004 +14Vdc +14Vdc +14Vdc 100K 100n 1N4004 LM324 100n LM324 1N4004 +14Vdc 24VAC_1 100n 24VAC_2...
  • Page 99 FABRICATOR 251 MOT SPOOL MOT COM MOT LOC GV SPOOL GV COM GV LOC CON6 +35Vdc +35Vdc +35Vdc Install jumper for use with MILLER spool gun which has no speed pot on the spool gun 560R 1/2W 560R 1/2W 560R 1/2W...

  • Page 100: Limited Warranty

    LIMITED WARRANTY August 2008 LIMITED WARRANTY: The Manufacturer, warrants to customers of authorized distributors ("Purchaser") that its products will be free of defects in workmanship or material. Should any failure to conform to this warranty appear within the warranty period stated below, the Manufacturer shall, upon notification thereof and substantiation that the product has been stored, installed, operated, and maintained in accordance with the Manufacturer's specifications, instructions, recommendations and recognized standard...

  • Page 101: Warranty Schedule

    August 2008 GMAW/FCAW (MIG) WELDING EQUIPMENT ARRANTY ERIOD ABOR Fabricator 251 Original Main Power Transformer and Inductor ....................5 years 3 years Original Main Power Rectifiers, Control P.C. Boards, power switch semi-conductors ........3 years 3 years All other original circuits and components including, but not limited to, relays, switches, contactors, solenoids, fans, electric motors.....................

Table of Contents