195399 PipeWorx 250 Amp MIG Gun
User Manual

SAFETY PRECAUTIONS — READ BEFORE USING

Protect yourself and others from injury – read, follow, and save these important safety precautions and operating instructions.

Symbol Usage

DANGER!  – Indicates a hazardous situation that, if not avoided, will result in death or serious injury. The possible hazards are shown in the adjoining symbols or explained in the text.
Indicates a hazardous situation that, if not avoided, could result in death or serious injury. The possible hazards are shown in the adjoining symbols or explained in the text.
NOTICE – Indicates statements not related to personal injury.
– Indicates special instructions.

This group of symbols means Warning! Watch Out!
ELECTRIC SHOCK, MOVING PARTS, and HOT PARTS hazards.
Consult symbols and related instructions below for necessary actions to avoid the hazards.

Arc Welding Hazards

The symbols shown below are used throughout this manual to call attention to and identify possible hazards. When you see the symbol, watch out, and follow the related instructions to avoid the hazard. The safety information given below is only a summary of the more complete safety information found in section 1-  Principal Safety Standards on page 3, and in the welding power source Owner’s Manual. Read and follow all Safety Standards.
Only qualified persons should install, operate, maintain, and repair this equipment. A qualified person is defined as one who, by possession of a recognized degree,  certificate, or professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter, the work, or the project and has received safety training to recognize and avoid the hazards involved.
During operation, keep everybody, especially children,  away.

ELECTRIC SHOCK can kill.

• Always wear dry insulating gloves.
• Insulate yourself from work and the ground.
• Do not touch live electrodes or electrical parts.
• Replace worn, damaged, or cracked guns or cables.
• Turn off the welding power source before changing the contact tip or gun parts.
• Keep all covers and handle securely in place.

FUMES AND GASES can be hazardous.

• Keep your head out of the fumes.
• Ventilate the area, or use a breathing device. The recommended way to determine adequate ventilation is to sample for the composition and quantity of fumes and gases to which personnel is exposed.
• Read and understand the Safety Data Sheets (SDSs) and the manufacturer’s instructions for adhesives, coatings, cleaners,  consumables, coolants, degreasers, fluxes, and metals.

MOVING PARTS can injure.

• Keep away from moving parts.
• Keep away from pinch points such as drive rolls.

WELDING can cause fire or explosion.

• Do not weld near flammable material.
• Do not weld on containers that have held combustibles, or on closed containers such as tanks, drums, or pipes unless they are properly prepared according to AWS F4.1 and AWS A6.0 (see Safety Standards).
• Watch for fire; keep an extinguisher nearby.
• Read and understand the Safety Data Sheets (SDSs) and the manufacturer’s instructions for adhesives, coatings, cleaners, consumables, coolants, degreasers, fluxes, and metals.

BUILDUP OF GAS can injure or kill.

• Shut off the compressed gas supply when not in use.
• Always ventilate confined spaces or use an approved air-supplied respirator.

ARC RAYS can burn eyes and skin.
Arc rays from the welding process produce intense visible and invisible (ultraviolet and infrared) rays that can burn eyes and skin. Sparks fly off from the weld.

• Wear an approved welding helmet fitted with proper shade of filter lenses to protect your face and eyes from arc rays sparks when welding or watching (see ANSI Z49.1 and Z87listed in Safety Standards).
• Wear approved safety glasses with side shields under your helmet.
• Use protective screens or barriers to protect others from flash, glare, and sparks; warn others not to watch the arc.
• Wear body protection made from leather or flame-resistant clothing (FRC). Body protection includes oil-free clothing such as leather gloves, a heavy shirt, cuffless trousers, high shoes, and a cap.

HOT PARTS can burn.

• Allow the gun to cool before touching it.
• Do not touch hot metal.
• Protect hot metal from contact by others.

NOISE can damage hearing.

Noise from some processes or equipment can damage hearing.

• Check for noise level limits exceeding those specified by OSHA.
• Use approved earplugs or earmuffs if the noise level is high.
• Warn others nearby about noise hazards.

WELDING WIRE can injure.

• Keep hands and body away from the gun tip when the trigger is pressed.

READ INSTRUCTIONS.

• Read and follow all labels and the Owner’s
  Manual carefully before installing, operating, or servicing the unit. Read the safety information at the beginning of the Manual and in each section.

• Use only genuine replacement parts from the manufacturer.

• Perform installation, maintenance, and service according to the Owner’s Manuals, industry standards, and national, state, and local codes.

California Proposition 65 Warnings

WARNING:  This product can expose you to chemicals including lead, which is known to the state of California to cause cancer and birth defects or other reproductive harm.
For more information, go to www.P65Warnings.ca.gov.

Principal Safety Standards

Safety in Welding, Cutting, and Allied Processes, American Welding Society standard ANSI Standard Z49.1. Website: www.aws.org.
Safe Practice For Occupational And Educational Eye And FaceProtection, ANSI Standard Z87.1, from American National
Standards Institute. Website: www.ansi.org.
Safe Practices for the Preparation of Containers and Piping forWelding and Cutting, American Welding Society Standard AWS F4.1. Website: www.aws.org.
National Electrical Code, NFPA Standard 70 from National Fire Protection Association. Website: www.nfpa.org.
Safe Handling of Compressed Gases in Cylinders, CGA Pamphlet P- 1 from Compressed Gas Association. Website: www.cganet.com.
Safety in Welding, Cutting, and Allied Processes, CSA Standard
W117.2 from Canadian Standards Association. Website: www.csagroup.org.
The standard for Fire Prevention During Welding, Cutting, and other hot Work, NFPA Standard 51B from National Fire Protection
Association. Website: www.nfpa.org.
OSHA, Occupational Safety and Health Standards for General Industry, Title 29, Code of Federal Regulations (CFR), Part 1910.177 Subpart N, Part 1910 Subpart Q, and Part 1926, Subpart J. Website: www.osha.gov.
SR7 2022-01

EMF Information

Electric current flowing through any conductor causes localized electric and magnetic fields (EMF). The current from arc welding (and allied processes including spot welding, gouging, plasma arc cutting, and induction heating operations) creates an EMF field around the welding circuit. EMF fields may interfere with some medical implants, e.g. Pacemakers. Protective measures for persons wearing medical implants have to be taken. For example, restrict access for passersby or conduct an individual risk assessment for welders. All welders should use the following procedures in order to minimize exposure to EMF fields from the welding circuit:

1. Keep cables close together by twisting or taping them, or using a cable cover.
2. Do not place your body between welding cables. Arrange cables to one side and away from the operator.
3. Do not coil or drape cables around your body.
4. Keep the head and trunk as far away from the equipment in the welding circuit as possible.
5. Connect the work clamp to the workpiece as close to the weld as possible.
6. Do not work next to, sit, or lean on the welding power source.
7. Do not weld whilst carrying the welding power source wire feeder.

About Implanted Medical Devices:
Implanted Medical Device wearers should consult their doctors and the device manufacturer before performing or going near arc welding, spot welding, gouging, plasma arc cutting, or induction heating operations. If cleared by your doctor, then following the above procedures is recommended.

Introduction

Thank you for choosing Bernard. The product you have purchased has been carefully assembled and factory tested prior to shipment. Should you experience problems with installation or performance, please refer to the “Troubleshooting Guide” in this manual.
Before installing, compare the equipment received against the invoice to verify that the shipment is complete and undamaged. It is the responsibility of the purchaser to file all claims of damage or loss that may have occurred during transit with the carrier.
The manual contains general information on the operation of this Bernard product. Before installing or operating any equipment, read and understand the information and safety precautions presented in this manual. Also, note the various data plates, labels, and tags attached to the product.
While every precaution has been taken to assure the accuracy of this manual, Bernard assumes no responsibility for errors or omissions. Bernard assumes no liability for damages resulting from the use of the information contained herein. Bernard shall have no liability to the Buyer for consequential damages or be liable to the in tort for any negligent manufacture of the goods or for the omissions of any warning therefrom.

Commercial Warranty

The product is warranted to be free from defects in material and workmanship for 1 year after the sale by an authorized Buyer. Straight handles, straight handle switches, and straight rear strain reliefs are covered by a lifetime warranty.
Bernard reserves the right to repair, replace or refund the purchase price of a nonconforming product. Product found not defective will be returned to the Buyer after notification by Customer Service.
Bernard makes no other warranty of any kind, expressed or implied, including, but not limited to the warranties of merchantability or fitness for any purpose. Bernard shall not be liable under any circumstances to Buyer, or to any person who shall purchase from Buyer, for damages of any kind. Including, but not limited to any, direct, indirect incidental or consequential damages or loss of production or loss of profits resulting from any cause whatsoever, including, but not limited to, any delay, act, error, or omission of Bernard.
Genuine Bernard parts must be used for safety and performance reasons or the warranty becomes invalid. Warranty shall not apply if an accident, abuse, or misuse damages a product, or if a product is modified in any way except by authorized Bernard personnel.

General Description

The Bernard PipeWorx MIG Gun is designed primarily for processing mild steel electrodes under GMAW (Gas Metal Arc Welding), MIG (Metal Inert Gas), MAG (Metal  Active Gas), FCAW (Flux Cored Arc Welding), and MOG (Metal without Gas).
The pipework MIG Gun provides rapid neck interchangeability, typically during production processes. The neck may also be positioned online within a 360-degree rotation. This position allows for movements between standard horizontal welding, overhead, and hard-to-reach side angles. The neck includes an optional jump liner system that effectively reduces costs associated with one-piece liner systems. Bernard is concerned about your higher productivity.

The pipework MIG Gun meets or exceeds NEMA (National Electrical Manufacturer’s Association) EW3 requirements for guns used in a wide variety of applications including aluminum, silicon bronze, and hard facing alloys to name a few. With Bernard’s flexibility, many applications can be accommodated with field- installed options increasing performance and maneuverability.

Installation

1. Your gun has been shipped with a specific feeder connector, neck, and sized for an electrode as per the part number indicated on its package. Please inspect the received gun against this part number for accuracy.

2. Turn off power prior to any installation.

3. Fully extend gun and cable. Press liner fully into power pin.

4. Safely expose approximately 2” (51 mm) of electrode beyond the feeder or adaptor block.

5. Power Pin
   Connect the power pin of the direct plug gun by sliding the electrode into the liner and the power fitting into the drive housing of the feeder. Fully seat the unit in position and tighten it into place as designated in the manufacturer’s instructions. On initial installations, a thin film of silicone lubricant will aid installation and prevent o-ring damage.
   Attach control lead wires to the appropriate plug, terminals, or lead kit. Plug or wire into the control circuit of the feeder as designated in the manufacturer’s instructions.
   If a gas hose is provided, connect to the feeder’s solenoid circuit to deliver shielding gas to the arc. If no gas hose is provided, gas is delivered through the power pin. Refer to the manufacturer’s instructions for proper gas connection at the feeder block or solenoid.

6. Remove the nozzle from the head assembly.

7. Pull contact tip from head/gas diffuser. An unobstructed electrode path has now been established.

8. Safely feed electrode through the gun and approximately 1” (25 mm) beyond the head/gas diffuser.

9. Reinstall the contact tip over the electrode and lock it into position by reinstalling the nozzle.

Welding current and duty cycle shall not exceed the published specification of this product. If such conditions exist, product life and performance will be reduced.

Helpful Operating Tips

Nozzles:

1. If anti-spatter is used, do not coat the nozzle insulator as this may degrade the insulating material.
2. The nozzle should be cleaned as often as possible. Spatter buildup can often lead to poor gas shielding or short-circuiting between the contact tip and the nozzle.
3. Spatter should be removed with the proper tools designed for spatter removal.
4. In high-temperature welding applications, heavy-duty consumables are recommended.

Contact Tips, Gas Diffusers:

1. Contact tips may be removed and rotated in a gas diffuser, providing an additional wear surface and extending the service life of the product.
2. Inspect the nozzle for spatter adhesion, blocked gas ports, and carburized contact surfaces. Clean as often as possible.
3. If anti-spatter is used, periodically check gas ports for blockage.

Feeder:

1. Check drive rolls for wear; be sure drive rolls and guide tubes are clean and free of debris. Do not overtighten drive rolls; set as per manufacturer’s specifications.
2. Use clean, non-corroded electrodes.
3. When installing or replacing electrodes, you may: remove burrs from the end of the electrode, remove the head/gas diffuser and contact tip, and/or straighten the first few inches of the electrode.
4. When using a dual shield electrode, periodically check gas ports in a gas diffuser for clogging caused by flux from within the electrode.

Cable:

1. Periodically check torques of neck and end fittings. Loose fittings can cause overheating and premature failure of the gun.
2. Sharp bends and loops in the cable should be avoided. Often the best solution is to suspend the wire feeder from a boom or trolley, thus eliminating a large number of bends and keeping the cable clear of hot weldments.
3. Do not immerse the liner into solvents for cleaning; the liner may be periodically blown out with compressed air.
4. Avoid rough surfaces and sharp edges that can cause tears and nicks in the cable jackets which can cause premature failure.
5. Periodically check all cables and ground connections.
6. Use anti-seize on all threaded connections.

End-User Stocking Recommendations:
Nozzles ……………………………….. 5 for every 1 gun in service
Contact Tips ………………………… 30 for every 1 gun in service
Gas Diffusers ………………………. 4 for every 1 gun in service
Triggers ………………………………. 1 for every 10 guns in service
Necks …………………………………. 1 for every 20 guns in service
Handle Kits ………………………….. 1 for every 20 guns in service
Replacement Cables ……………… 1 for every 20 guns in service
Strain Relief Kits ………………….. 1 for every 20 guns in service
Adaptor Kits ………………………… Order as Necessary
Power Pin Kits …………………….. Order as Necessary
These stocking recommendations are only initial guidelines based on an 80-hour work period. You should work closely with your distributor to tailor a stocking program that suits your specific needs. Results will vary.

Maintenance and Repair

See pages 6 and 7 for parts lists

Disconnect gun from equipment, allow to cool, and remove the electrode from liner before servicing.

Section 1. Nozzle

A. Removal
The threaded fit nozzle can be removed by turning in a counterclockwise direction.
B. Service
Inspect the nozzle for cracks and degradation of insulation.
Clean the nozzle as often as possible to prevent spatter build-up which can lead to poor gas shielding or short-circuiting. Replace the nozzle when loose, worn, or producing erratic gas shield.
C. Installation
Replace the threaded fit nozzle by threading in a clockwise direction. The nozzle body is used to secure the contact tip.

Section 2. Contact Tip

Bernard has designed Centerfire™ Contact Tips to allow rapid installation and adjustment.
A. Removal
Cut electrode and remove all burrs. Remove threaded fit nozzle by turning in a counterclockwise direction. Pull the Centerfire Contact Tip from the gas diffuser.

B. Service
To extend contact tip life, reface the front of the contact tip and clean the bore. Contact tips may be rotated in the gas diffuser/ head socket providing additional wear surface and extending the service life of the product.
C. Installation
Replacement is accomplished by cutting electrodes and removing all burrs. Slide contact tip over electrode into the gas diffuser and replace threaded fit nozzle by threading in a clockwise direction. The nozzle body is used to secure the contact tip.

Section 3. Gas Diffuser

A. Removal
The head may be removed with an appropriate wrench in a counterclockwise rotation.
B. Service
Inspect head for spatter, blocked gas ports, and carburized surfaces. Clean as often as possible. Replace with new gas diffuser when wear prevents engagement of contact tip or nozzle.
C. Installation
Firmly secure gas diffuser with an appropriate wrench in a clockwise rotation, torque to 144 in-lbs. Be sure the insulator cap is in place as shown in figure

1.

Section 4. Neck

A. Removal
Grasp the lock nut and rotate counterclockwise, rotation will free the neck from end fitting.
B. Installation
Before installing, inspect neck and end fitting for debris, and clean if necessary. Install neck in reverse order, torque to 38 in-lbs. NOTE: Refer to Jump Liner literature for liner cut-off sizes (if used).

Section 5. Jump liner (Optional)

A. Removal
Remove nozzle, gas diffuser, and neck. Remove used jump liner from the back end of the neck.
B. Service
Inspect for excessive wear and debris on the inside diameter. Do not dip the jump liner in solvents for cleaning. Jump liners may be periodically blown out with shop air. Replace with new jump liner when excessive wear or debris produces poor electrode feed.
C. Installation
Insert jump liner making sure the liner stop is fully seated at the back of the neck. Take the tapered end of the neck and insert it into the end fitting of the gun handle. Install the neck.  rim and deburr the liner past the nozzle end of the neck. Install gas diffuser and nozzle.

Section 6. Handle

A. Removal
Remove screws, and post fasteners. Separate and remove the handle halves.
B. Service
Inspect for cracks, deformation of hex areas, debris, holes, loose or missing threaded inserts, excessive wear, exterior heat deformation, and warpage. If any of the above conditions exist, replace it with a new handle or clean all surfaces with mild detergent and reinstall. Test switch for continuity. Clean any debris from the trigger, if necessary, replace it with a new trigger handle assembly.
C. Installation
Position cable in handle half. Pres sing lead wire terminal fully into terminals of the switch. Position remaining handle half so leads are not pinched and movement of the trigger is not impaired. Post fasteners, and screws; torque to 10 in-lbs (1.1 Nm)

Section 7. Cable

A. Inspection
Replace the cable assembly if the following conditions are evident on the exterior of the cable: cuts and/or abrasions in cable jacketing exposing copper stranding, abrupt kinking of the cable causing abnormal heating in the area of bend, loss of control circuit function as verified through continuity tests, slippage of insulating jacket exposing copper stranding, or crushed cable.
B. Replacement
Using a replacement cable, install the terminated cable end to the adapter block. It will be necessary to install or confirm that the flexible strain relief and cap is in place before preparation (See Figure 3).

Torque the end fitting into the adapter block to 17 ft-lbs (23 Nm). Strip the appropriate control leads 1/4” (6.4 mm) and crimp to appropriate butt connections of trigger leads. Finalize installation.
C. Repair
There is no authorized repair of welding cable due to product liability. Control leads may be repaired by splicing high temperature 18 AWG lead wire with nylon coated butt connectors, or spare leads can be used.

Section 8. Liners

A. Removal
Remove nozzle and gas diffuser
Guns with jump liner: Remove neck. Lay cable straight.
Grasp the liner lock which protrudes from the power pin (some direct plugs may require removal of additional components to access the liner lock) and remove it from cable assembly.
B. Service
Inspect for excessive wear and debris on the inside diameter. Do not dip liner in solvents for cleaning. The liner may be periodically blown out with shop air. Replace with the new liner when excessive wear or debris produces poor electrode feed.

C. Installation
Insert liner into power pin with cable laying straight. Continue until the liner lock is fully seated into the power pin. A twisting motion may be necessary to seat the o-ring (some direct plugs may require the installation of additional components to secure the liner).
Make sure cable is straight, trim and deburr liner beyond the end of the neck to 9/16” (14.3 mm) When using Jump Liner: Trim and deburr liner with 1/4” (6.4 mm) extending beyond the gun handle. Install neck. Install gas diffuser and nozzle.

Section 9. Rigid Strain Relief

A. Removal
Using a counterclockwise motion, unseat cap and sleeve assembly from rigid strain relief. Remove the screw securing strain relief to the adapter block.
B. Service
Inspect all components for cracks, debris, excessive wear, and breakage. Replace with new components if the safety or performance of the product is compromised.
C. Installation
Align flats in rigid strain relief with flats on adapter block. Slide strain relief onto the adapter block and install the screw. Torque screw to 12 in-lbs (1.4 Nm). Using the arrows on the cap to align with mating grooves, slide the cap and sleeve assembly toward the rigid strain relief until seated, and turn clockwise until an engaging snap is felt.

Miller Power Pins

A. Removal
Remove the power pin tip that retains the liner from the power pin with the appropriate wrench. Remove liner and rigid strain relief from gun assembly. Position control lead wires as necessary as not to damage them. Remove power pin from adapter block using appropriate wrenches in a counterclockwise rotation (See Figure 3).

B. Service
Test lead wires for continuity when the trigger is engaged. Lubricate o-rings with silicone lubricant. Inspect all components for cracks, debris, excessive wear, and breakage. Replace with new components, if the safety or performance of the product is compromised.
C. Installation
Assemble power pin onto adapter block in a clockwise rotation using appropriate wrenches. Torque to 13 ft-lbs (17.6 Nm)
Install liner. Install power pin tip and tighten to retain liner assembly (See Figure 3).

250 Amp Gun Exploded Diagram and Parts List

Gun Part Number: 195399

300 Amp Gun Exploded Diagram and Parts List

Gun Part Number: 195400

Troubleshooting Guide

2. Broken control lead.
3. Poor adaptor connection.
4. Worn or broken switch.
5. Improper drive roll size.
6. Drive roll tension misadjusted.
7. Burn back to contact tip.
8. Wrong size liner.
9. Buildup inside of the liner.| 1. Consult feeder manufacturer.
2 a. Test & connect spare control lead.
b. Install new cable.
3. Test & replace leads and/or contact pins.
4. Replace.
5. Replace with the proper size.
6. Adjust tension at the feeder.
7. See ‘Contact Tip Burn Back’.
8. Replace with the correct size.
9. Replace the liner, and check the condition of the electrode.
2. Contact Tip burn back.| 1. Improper voltage and/or wire feed speed.
2. Erratic wire feeding.
3. Improper contact tip stick out.
4. Improper electrode stick out.
5. Faulty ground.| 1. Set parameters.
2. See ‘Erratic Wire Feeding’.
3. Adjust nozzle/contact tip relationship.
4. Adjust the gun to the base metal relationship.
5. Repair all cables & connections.
3. Contact Tip disengages from the head.| 1. Worn gas diffuser.
2. Improper contact tip installation.
3. Extreme heat or duty cycle.| 1. Replace contact tip and/or gas diffuser.
2. Install as per ‘Maintenance & Repair’ (Section 2).
3. Replace with heavy-duty consumables as per ‘Accessories’ Section.
4. Short contact tip life.| 1. Contact tip size.
2. Electrode eroding contact tip.
3. Exceeding duty cycle.| 1. Replace with proper size.
2. Inspect and/or change drive rolls.
3. Replace with properly rated Bernard MIG Gun.
5. Erratic arc.| 1. Worn contact tip.
2. Buildup inside of the liner.
3. Wrong contact tip size.
4. Not enough bend in the neck.| 1. Replace.
2. Replace the liner, and check the condition of the electrode.
3. Replace with correct size contact tip.
4. Replace with 45º or 60º neck.
6. Erratic wire feeding.| 1. Buildup inside of liner.
2. Wrong size liner.
3. Improper drive roll size.
4. Worn drive roll.
5. Improper guide tube relationship.
6. Improper wire guide diameter.
7. Gaps at liner junctions.
8. Feeder malfunction.
9. Contact tip.| 1. Replace the liner, and check the condition of the electrode.
2. Replace with a new liner of proper size.
3. Replace with proper size drive roll.
4 a. Replace with new drive roll.
b. Stone edge of the groove on drive roll.
5 a. Adjust/replace guide as close to driving rolls as possible.
b. Eliminate all gaps in the electrode path.
6. Replace with proper guide diameter.
7 a. Replace with new liner trimming as per ‘Maintenance & Repair’ (Section 5 & 8).
b. Replace guide tube/liner, trim as close to the mating component as possible.
8. Consult feeder manufacturer.
9. Inspect and replace.
7. Extreme spatter.| 1. Improper machine parameters.
2. Improper contact tip installation.
3. Improper shielding.
4. Contaminated wire or workpiece.| 1. Adjust parameters.
2. Adjust nozzle/contact tip relationship.
3 a. Verify shielding gas coverage.
b. Verify gas mixture.
4. Clean wire and workpiece.
8. Porosity in the weld.| 1. Insulator worn.
2. Gas diffuser damaged.
3. Extreme heat or duty cycle.
4. Solenoid faulty.
5. No gas.
6. Flow improperly set.
7. Gas ports plugged.
8. Ruptured gas hose.
9. Control circuit loss.
10. Worn, cut, or missing o-rings.
11. Loose fittings.| 1. Replace nozzle/insulator.
2. Replace the gas diffuser.
3. Replace with heavy-duty consumables.
4. Replace solenoid.
5 a. Install full tanks.
b. Check supply.
c. Hose leaks.
6. Adjust.
7 a. Clean or replace the gas diffuser.
b. Clean nozzle.
8. Repair or replace cable or line.
9. See ‘Electrode Does Not Feed’.
10. Replace o-rings
11. Tighten gun & cable connections to the specified torque. See ‘Maintenance & Repair’ (Section 7).
9. Gun running hot.| 1. Exceeding duty cycle.
2. Loose or poor power connection.| 1. a. Replace with properly rated Bernard gun.
b. Decrease parameters to within gun rating.
2. a. Clean, tighten or replace cable grounding connection.
b. Tighten gun & cable connections to the specified torque. See ‘Maintenance & Repair’ (Section 7).
10. Liner is discolored full length.| 1. Short circuit to the electrode.
2. Broken copper stranding in the power cable.| 1. Isolate electrode reel from feeder and drive block. Consult feeder manufacturers manual.
2. Replace MIG Gun.
11. Sporadic feeding of the aluminum electrode.| 1. Contact tip galling.
2. Synthetic liner melting.
3. Wire deformed by feed rolls.| 1. Inspect & replace.
2. a. Replace liner.
b. Replace with composite liner.
c. Replace with Q-Gun neck and jump liner.
3. Adjust drive rolls as per feeder manufacturer’s manual.

*In some cases with aluminum and mild steel, it may be necessary to use a contact tip with either a larger or smaller bore size.

Notes

Safety DepenDS On yOu!
DO NOT INSTALL, OPERATE OR REPAIR THIS EQUIPMENT WITHOUT READING THIS OPERATING MANUAL AND THE ARC WELDING SAFETY PRECAUTIONS ON THE INSIDE FRONT COVER.
Bernard™ Guns are designed and built with safety in mind, but operators must follow prescribed safety guidelines.

Miller Electric Mfg. Co.
An Illinois Tool Works Company
1635 West Spencer Street
Appleton, WI 54914 USA
International Headquarters-USA
USA Phone: 920-735-4504 Auto-Attended
USA & Canada FAX: 920-735-4125
International FAX: 920-735-4125
European Headquarters – United Kingdom
Phone: 44 (0) 1204-593493
Fax: 44 (0) 1204-598066
MillerWelds.com

© 2022 Bernard Printed in U.S.A. DFB-OPPW-2.4

References

• Home
• American Welding Society (AWS) - Welding Excellence Worldwide
• Product Certification & Standards Development - CSA Group
• NFPA | The National Fire Protection Association
• P65Warnings.ca.gov

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