ESAB Migmaster 300i cvcc Welding Power Supply User manual

Brand: ESAB

Model: Migmaster 300i cvcc Welding Power Supply

Category: Welding System

Type: User manual

Migmaster 300i cvcc

WELDING POWER SUPPLY

SERVICE AND MAINTENANCE

BEFORE SERVICING, READ AND COMPLY WITH THESE INSTRUCTIONS

F-15-097-A

March, 2001

TABLE OF CONTENTS

SECTION TITLE PAGE

PARAGRAPH

I SAFETY PRECAUTIONS ........................................................................................................ 4

II INTRODUCTION ..................................................................................................................... 6

2.1 General ............................................................................................................................ 6

2.2 Receiving-Handling .......................................................................................................... 6

2.3 Duty Cycle ........................................................................................................................ 6

2.3.1 Volt/Ampere Curves .........................................................................................................6

2.4 Description ....................................................................................................................... 7

2.4.1 Available Packages and Contents .................................................................................... 7

2.4.2 Power Source................................................................................................................... 8

2.4.3 Wire Feeder ..................................................................................................................... 8

2.4.4 MT-200cc Torch ............................................................................................................... 8

2.4.5 Controls............................................................................................................................ 8

2.4.6 Running Gear ................................................................................................................... 8

2.5 Optional Equipment .......................................................................................................... 8

2.6 Safety ............................................................................................................................... 9

III OPERATIONAL DESCRIPTION ............................................................................................ 10

3.1 General .......................................................................................................................... 10

3.2 Power Source .................................................................................................................10

3.2.1 Wire Feeder ................................................................................................................... 10

3.2.2 Power Unit ..................................................................................................................... 10

3.2.3 Control Electronics Board ............................................................................................... 10

3.3 Display and Controls ...................................................................................................... 10

3.3.1 General .......................................................................................................................... 10

3.3.2 Operational Description of Display ................................................................................. 11

3.3.3 Operational Procedure of Display ................................................................................... 11

3.4 Finding Welding Parameters in MIG .............................................................................. 12

3.5 Synergic Relationships and Functions ............................................................................ 12

3.6 Servo Functions ............................................................................................................. 12

3.7 Saving Welding Conditions ............................................................................................ 13

3.8 Fault Conditions .............................................................................................................13

IV INSTALLATION OF POWER SOURCE AND ACCESSORIES.............................................. 14

4.1 Location ......................................................................................................................... 14

4.2 Assembly of Rear Wheels .............................................................................................. 14

4.3 Electrical Input Connections ........................................................................................... 14

4.3.1 Input Electrical Requirements ........................................................................................ 14

4.3.2 Input Conductor Connections ......................................................................................... 14

4.4 Secondary Output Connections ...................................................................................... 15

4.5 Welding Cable Connections ........................................................................................... 16

4.6 Installation for MIG Welding ........................................................................................... 16

4.6.1 Torch Connection (MT-200cc) ....................................................................................... 16

4.6.2 Torch Polarity Cable and Work Cable ............................................................................ 16

4.6.3 Wire Feeder Mechanism ................................................................................................ 17

4.6.3.1 Drive Rolls ...................................................................................................................... 17

4.6.3.2 Welding Wire Spool .......................................................................................................17

4.6.3.3 Threading Welding Wire ................................................................................................ 17

4.6.3.4 Brake Drag Adjustment .................................................................................................. 17

4.7 Connection of Shielding Gas Supply .............................................................................. 18

4.7.1 Gas Shielding Supply ..................................................................................................... 18

4.7.2 Connection ..................................................................................................................... 18

4.7.3 Regulating Flow ............................................................................................................. 18

4.7.4 Stopping Work .............................................................................................................. 18

TABLE OF CONTENTS - (Cont)

SECTION TITLE PAGE

PARAGRAPH

4.8 MIG-41A Push-Pull Gun ................................................................................................. 19

4.9 Installation for TIG Welding ............................................................................................ 19

4.9.1 Using Torch With Central Connector.............................................................................. 19

4.9.2 Using TIG Torch With Gas Valve On ............................................................................. 19

4.10 Installation for Stick Welding .......................................................................................... 20

4.11 Switching Between Processes ....................................................................................... 20

V SETUP AND USAGE OF MIGMASTER 300i ......................................................................... 21

5.1 Controls.......................................................................................................................... 21

5.1.1 Power Switch ................................................................................................................. 21

5.1.2 Process Selector Switch................................................................................................. 21

5.1.3 Control Display Screen ................................................................................................... 21

5.1.4 Secondary Welding Connections ................................................................................... 21

5.2 Operating Procedures .................................................................................................... 21

5.2.1 Operating Safety Precautions ......................................................................................... 21

5.2.2 Pre-weld Requirement.................................................................................................... 22

5.3 Process Setup ................................................................................................................22

5.3.1 Stick Welding ................................................................................................................. 22

5.3.2 TIG Welding ................................................................................................................... 24

5.3.3 MIG Welding .................................................................................................................. 24

5.3.3.1 Guided Mode of Setting Welding Parameters ................................................................ 24

5.3.3.2 Manual Mode of Setting Welding Parameters ................................................................ 24

5.4 Description of Trigger Type Options ............................................................................... 31

5.4.1 Selection of Start Type ................................................................................................... 32

5.4.2 Setting Burnback Time ................................................................................................... 32

VI SERVICE ............................................................................................................................... 33

6.1 Maintenance................................................................................................................... 33

6.2 Inspection and Service ................................................................................................... 33

6.2.1 Power Source ................................................................................................................. 33

6.2.1.2 Fan Motor ....................................................................................................................... 34

6.2.1.3 Transformer ................................................................................................................... 34

6.2.1.4 24 Volt Wire Feeder and Control Circuits ....................................................................... 34

6.2.1.5 Over-Temperature Protection......................................................................................... 34

6.2.2 Wire Feeder ................................................................................................................... 34

VII TROUBLESHOOTING AND REPAIR .................................................................................... 35

7.1 Troubleshooting ............................................................................................................. 35

7.1.1 If Motor Does Not Run ................................................................................................... 35

7.1.2 Drive Roll Pressure Adjustment ..................................................................................... 35

7.1.3 Solenoid Valve Replacement ......................................................................................... 35

7.2 Troubleshooting Guide ................................................................................................... 35

VIII PARTS ................................................................................................................................... 41

8.1 Spare Parts .................................................................................................................... 41

8.2 Replacement Parts......................................................................................................... 41

8.3 Ordering ......................................................................................................................... 41

WARNING: These Safety Precautions are for

your protection. They summarize precaution-

ary information from the references listed in

Additional Safety Information section. Before

performing any installation or operating procedures, be

sure to read and follow the safety precautions listed below

as well as all other manuals, material safety data sheets,

labels, etc. Failure to observe Safety Precautions can result

in injury or death.

PROTECT YOURSELF AND OTHERS

Some welding, cutting, and gouging

processes are noisy and require ear

protection. The arc, like the sun, emits

ultraviolet (UV) and other radiation and

can injure skin and eyes. Hot metal can cause burns.

Training in the proper use of the processes and equip-

ment is essential to prevent accidents. Therefore:

1. Always wear safety glasses with side shields in any work

area, even if welding helmets, face shields, and goggles

are also required.

2. Use a face shield fitted with the correct filter and cover

plates to protect your eyes, face, neck, and ears from

sparks and rays of the arc when operating or observing

operations. Warn bystanders not to watch the arc and

not to expose themselves to the rays of the electric-arc

or hot metal.

3. Wear flameproof gauntlet type gloves, heavy long-sleeve

shirt, cuffless trousers, high-topped shoes, and a weld-

ing helmet or cap for hair protection, to protect against

arc rays and hot sparks or hot metal. A flameproof apron

may also be desirable as protection against radiated

heat and sparks.

4. Hot sparks or metal can lodge in rolled up sleeves,

trouser cuffs, or pockets. Sleeves and collars should be

kept buttoned, and open pockets eliminated from the

front of clothing

5. Protect other personnel from arc rays and hot sparks

with a suitable non-flammable partition or curtains.

6. Use goggles over safety glasses when chipping slag or

grinding. Chipped slag may be hot and can fly far.

Bystanders should also wear goggles over safety glasses.

FIRES AND EXPLOSIONS -- Heat from

flames and arcs can start fires. Hot slag

or sparks can also cause fires and ex-

plosions. Therefore:

1. Remove all combustible materials well away from the

work area or cover the materials with a protective non-

flammable covering. Combustible materials include wood,

cloth, sawdust, liquid and gas fuels, solvents, paints and

coatings, paper, etc.

2. Hot sparks or hot metal can fall through cracks or

crevices in floors or wall openings and cause a hidden

smoldering fire or fires on the floor below. Make certain

that such openings are protected from hot sparks and

metal.“

3. Do not weld, cut or perform other hot work until the

workpiece has been completely cleaned so that there

are no substances on the workpiece which might pro-

duce flammable or toxic vapors. Do not do hot work on

closed containers. They may explode.

4. Have fire extinguishing equipment handy for instant use,

such as a garden hose, water pail, sand bucket, or

portable fire extinguisher. Be sure you are trained in its

use.

SAFETY PRECAUTIONS

10/98

5. Do not use equipment beyond its ratings. For example,

overloaded welding cable can overheat and create a fire

hazard.

6. After completing operations, inspect the work area to

make certain there are no hot sparks or hot metal which

could cause a later fire. Use fire watchers when neces-

sary.

7. For additional information, refer to NFPA Standard 51B,

"Fire Prevention in Use of Cutting and Welding Pro-

cesses", available from the National Fire Protection Asso-

ciation, Batterymarch Park, Quincy, MA 02269.

ELECTRICAL SHOCK -- Contact with live

electrical parts and ground can cause

severe injury or death. DO NOT use AC

welding current in damp areas, if move-

ment is confined, or if there is danger of

falling.

1. Be sure the power source frame (chassis) is connected

to the ground system of the input power.

2. Connect the workpiece to a good electrical ground.

3. Connect the work cable to the workpiece. A poor or

missing connection can expose you or others to a fatal

shock.

4. Use well-maintained equipment. Replace worn or dam-

aged cables.

5. Keep everything dry, including clothing, work area,

cables, torch/electrode holder, and power source.

6. Make sure that all parts of your body are insulated from

work and from ground.

7. Do not stand directly on metal or the earth while working

in tight quarters or a damp area; stand on dry boards or

an insulating platform and wear rubber-soled shoes.

8. Put on dry, hole-free gloves before turning on the power.

9. Turn off the power before removing your gloves.

10. Refer to ANSI/ASC Standard Z49.1 (listed on next page)

for specific grounding recommendations. Do not mis-

take the work lead for a ground cable.

ELECTRIC AND MAGNETIC FIELDS —

May be dangerous. Electric current flow-

ing through any conductor causes lo-

calized Electric and Magnetic Fields

(EMF). Welding and cutting current cre-

ates EMF around welding cables and

welding machines. Therefore:

1. Welders having pacemakers should consult their physi-

cian before welding. EMF may interfere with some pace-

makers.

2. Exposure to EMF may have other health effects which are

unknown.

3. Welders should use the following procedures to minimize

exposure to EMF:

A. Route the electrode and work cables together. Secure

them with tape when possible.

B. Never coil the torch or work cable around your body.

C. Do not place your body between the torch and work

cables. Route cables on the same side of your body.

D. Connect the work cable to the workpiece as close as

possible to the area being welded.

E. Keep welding power source and cables as far away

from your body as possible.

FUMES AND GASES -- Fumes and

gases, can cause discomfort or harm,

particularly in confined spaces. Do

not breathe fumes and gases. Shield-

ing gases can cause asphyxiation.

Therefore:

1. Always provide adequate ventilation in the work area by

natural or mechanical means. Do not weld, cut, or gouge

on materials such as galvanized steel, stainless steel,

copper, zinc, lead, beryllium, or cadmium unless posi-

tive mechanical ventilation is provided. Do not breathe

fumes from these materials.

2. Do not operate near degreasing and spraying opera-

tions. The heat or arc rays can react with chlorinated

hydrocarbon vapors to form phosgene, a highly toxic

gas, and other irritant gases.

3. If you develop momentary eye, nose, or throat irritation

while operating, this is an indication that ventilation is not

adequate. Stop work and take necessary steps to im-

prove ventilation in the work area. Do not continue to

operate if physical discomfort persists.

4. Refer to ANSI/ASC Standard Z49.1 (see listing below)

for specific ventilation recommendations.

5. WARNING: This product, when used for welding or

cutting, produces fumes or gases which

contain chemicals known to the State of

California to cause birth defects and, in

some cases, cancer. (California Health &

Safety Code

§25249.5 et seq.)

CYLINDER HANDLING -- Cylinders, if

mishandled, can rupture and violently

release gas. Sudden rupture of cylin-

der, valve, or relief device can injure or

kill. Therefore:

1. Use the proper gas for the process and use the proper

pressure reducing regulator designed to operate from

the compressed gas cylinder. Do not use adaptors.

Maintain hoses and fittings in good condition. Follow

manufacturer's operating instructions for mounting regu-

lator to a compressed gas cylinder.

2. Always secure cylinders in an upright position by chain

or strap to suitable hand trucks, undercarriages, benches,

walls, post, or racks. Never secure cylinders to work

tables or fixtures where they may become part of an

electrical circuit.

3. When not in use, keep cylinder valves closed. Have

valve protection cap in place if regulator is not con-

nected. Secure and move cylinders by using suitable

hand trucks. Avoid rough handling of cylinders.

4. Locate cylinders away from heat, sparks, and flames.

Never strike an arc on a cylinder.

5. For additional information, refer to CGA Standard P-1,

"Precautions for Safe Handling of Compressed Gases in

Cylinders", which is available from Compressed Gas

Association, 1235 Jefferson Davis Highway, Arlington,

VA 22202.

EQUIPMENT MAINTENANCE -- Faulty or

improperly maintained equipment can

cause injury or death. Therefore:

1. Always have qualified personnel perform the installa-

tion, troubleshooting, and maintenance work. Do not

perform any electrical work unless you are qualified to

perform such work.

2. Before performing any maintenance work inside a power

source, disconnect the power source from the incoming

electrical power.

3. Maintain cables, grounding wire, connections, power

cord, and power supply in safe working order. Do not

operate any equipment in faulty condition.

4. Do not abuse any equipment or accessories. Keep

equipment away from heat sources such as furnaces,

wet conditions such as water puddles, oil or grease,

corrosive atmospheres and inclement weather.

5. Keep all safety devices and cabinet covers in position

and in good repair.

6. Use equipment only for its intended purpose. Do not

modify it in any manner.

ADDITIONAL SAFETY INFORMATION -- For

more information on safe practices for elec-

tric arc welding and cutting equipment, ask

your supplier for a copy of "Precautions and

Safe Practices for Arc Welding, Cutting and

Gouging", Form 52-529.

The following publications, which are available from the

American Welding Society, 550 N.W. LeJuene Road, Mi-

ami, FL 33126, are recommended to you:

1. ANSI/ASC Z49.1 - "Safety in Welding and Cutting"

2. AWS C5.1 - "Recommended Practices for Plasma Arc

Welding"

3. AWS C5.2 - "Recommended Practices for Plasma Arc

Cutting"

4. AWS C5.3 - "Recommended Practices for Air Carbon

Arc Gouging and Cutting"

5. AWS C5.5 - "Recommended Practices for Gas Tungsten

Arc Welding“

6. AWS C5.6 - "Recommended Practices for Gas Metal Arc

Welding"“

7. AWS SP - "Safe Practices" - Reprint, Welding Hand-

book.

8. ANSI/AWS F4.1, "Recommended Safe Practices for

Welding and Cutting of Containers That Have Held

Hazardous Substances."

MEANING OF SYMBOLS - As used through-

out this manual: Means Attention! Be Alert!

Your safety is involved.

Means immediate hazards which, if

not avoided, will result in immediate,

serious personal injury or loss of life.

Means potential hazards which could

result in personal injury or loss of life.

Means hazards which could result in

minor personal injury.

SP98-10

II. INTRODUCTION

2.1 GENERAL

This manual has been prepared for experienced weld-

ers. Do NOT permit untrained persons to install, oper-

ate or maintain this equipment. Do NOT attempt to

install or operate this equipment until you have read

and fully understand these instructions.

This manual is intended for use in familiarizing per-

sonnel with the design and operation of this equipment.

All information presented here should be read care-

fully before installing and using this equipment.

2.2 RECEIVING-HANDLING

Upon receipt of this equipment, clean all packing

material from around the unit and immediately

inspect for any damage that may have occurred

during shipment. Any claims for loss or damage

occurring in transit must be filed with the carrier.

The carrier will furnish a copy of the bill of lading

and the freight bill on request, if the need to file a

damage claim arises.

When requesting information regarding this equip-

ment, make sure that you include product name,

part number, and serial number.

2.3 DUTY CYCLE (Figure 2-1)

The duty cycle of the equipment is the percent-

age of a 10-minute period which it can operate

safely at a given output current. The Migmaster

300i is rated at 300 amps at 40% duty cycle.

Figure 2.1 Duty Cycle

2.3.1 VOLT/AMPERE CURVES

(Figure 2-2)

The Volt/Ampere curves show the output voltage

available at any given output current. The actual

operating point of load Voltage and Current is

determined by process, electrode, shield gas, wire

feed speed, and operating technique.

Figure 2-2 Volt/Ampere Curves

2.4 DESCRIPTION

The Migmaster 300i is a dc welding system designed

for MIG Welding (GMAW), TIG (GTAW) or STICK

(SMAW). In the MIG mode this unit is capable of oper-

ating with short arc or spray arc transfer and handles

both solid wires and tubular cored wires. This unit is

suitable for carbon steel, stainless steel, aluminum and

many other alloys. It provides a Power Source with

built-in wire feeder and undercarriage with provisions

for one gas cylinder.

2.4.1 AVAILABLE PACKAGES AND CONTENTS

Each of the following packages include the Power

Source, with the built-in wire feeder, factory installed

undercarriage and cylinder rack, MT-200cc MIG Torch

(with .035" and .045" accessories), two dual groove

feed rolls (.023"/.030" and .034"/.045"), regulator and

adjustable flowmeter, 10' gas hose, 10' work cable and

clamp, 10' primary cable (with plug and receptacle),

and Welding Handbooks.

Description Part Number

Migmaster 300i cvcc .................................... 604575

w/10' MT-200cc Torch

Migmaster 300i cvcc .................................... 604576

w/12' MT-200cc Torch

Migmaster 300i cvcc ................................... 604577

w/15' MT-200cc Torch

Table 2-1. Specifications

Rated dc Output

40% duty cycle 300 amps @ 32 V dc

60% duty cycle (NEMA Class I) 250 Amps @ 30 V dc

Output Current Range

Mig (GMAW) 35 - 300 amps

Tig (GTAW) 10 - 300 amps

Stick (SMAW) 40 - 300 amps

Output Voltage (open circuit)

Mig (GMAW) 40 V dc

Tig (GTAW) 40 V dc

Stick (SMAW) 70 V dc

Rated Primary Input @ 300 amp

rated load

208/230 V ac, 72/65 amps, single-phase, 50/60 Hz

Wire Feed Range

65 - 655 ipm

Dimensions (with cylinder rack

and wheels)

Length 40" (102 cm)

Width 19.5" (50 cm)

Height 32.25 (82 cm)

Weight (no cylinder)

175 lbs (80 kg)

CSA

approval pending

Fig. 2-3. (Dimensions-see Table 2-1)

2.4.2 POWER SOURCE

The Power Source consists of an inverter dc power

supply for single-phase 208 V or 230 V primary con-

nection.

2.4.3 WIRE FEEDER

The wire feeder is built into the Power Source cabinet,

housed separately from the electrical components.

Cooling air is not drawn through the wire feeder mecha-

nism, thus reducing its exposure to dirt and dust.

The wire feeder pushes wire at speeds up to 655 ipm

(inches per minute). The purge/inch switch mounted

inside the Power Source cabinet allows the operator to

advance the wire without activating the torch.

2.4.4 MT-200cc TORCH

This air-cooled welding gun is supplied complete and

ready to weld with 0.035 inch steel wire. The torch

accommodates 0.045 inch wire by changing the con-

tact tip.

2.4.5 CONTROLS

The Migmaster 300i can be used to weld hard, alumi-

num, and flux cored wire . Control of the Power Source

and its different applications is provided by the 2-line,

32-character display screen. The operator selects the

process desired by scrolling through the menu selec-

tions. A detailed description of the Power Source con-

trols is included in Section III of this manual.

2.4.6 RUNNING GEAR

The Migmaster 300i is equipped with a running gear

with swiveled front wheels and a gas cylinder support.

The rear wheels are packed loose for shipping and are

easily installed, as described in paragraph 4.2.

Table 2-2. Contact Tips and Liners Table 2-3. Guide Tubes and Feed Rolls

Wire

Size & Type

Standard Duty Contact Tips* Liners

Short Medium Long 10’ 12" 15’

Hard Wires &

Cored Wires

.023" (.6mm)

-- 20543 999742 999743** -- --

.030" (.8mm) -- 20544 996994 948850 17717 --

.035"(.9mm) -- 996995 996996 2075237 17718 2075238

.045"(1.2mm) -- 996999 996998 2075237 17718 2075238

.052"(1.4mm) 948340 2075349 -- 2075239 17719 2075240

1/16"(1.6mm) 948341 996997 -- 2075239 17719 2075240

Soft Wires

(aluminum)

.035"(.9mm)

-- 996995 996996 948862 -- --

3/64" 999578 996999 996998 948863 -- --

Wire

Size & Type

Guide

Tube

Feed

Roll

Hard Wires -

"V" Groove

.023"(.6mm)

21163 21155

.030"(.8mm) 21164 21155

.035"(.9mm) 21165 21156

.045"(1.2mm) 21165 21156

Cored Wires -

Serrated

.030"(.8mm)

21164 21160

.035"(.9mm) 21165 21160

.045"(1.2mm) 21165 21161

.052"(1.4mm) 21166 21161

1/16"(1.6mm) 21166 21161

Soft Wires

(aluminum)-

"U" Groove

.035"(.9mm)

21167* 21158

3/64"(1.2mm) 21168* 21158

Short contact tips are generally recommended to give proper wire stick out for flux cored wire welding.

Medium contact tips are generally recommended to give proper wire stick out for spray arc Mig welding.

Long contact tips are generally recommended to give good visibility and proper wire stick out for short

arc Mig welding.

**Requires support liner for .023" wire. Order P/N 999797.

2.5 OPTIONAL EQUIPMENT

A. Mig 41A Push/Pull MIG Torch Assembly; includes

liner, contact tip, feed roll, and nozzle.

15 ft, .035" soft wire ............................... 604417

25 ft, 3/64" soft wire ............................... 604578

B. Mig 41A Push/Pull Basic MIG Torch; does not

include liner, feed roll, or contact tip; order sepa-

rately (see Form F-7036).

15 ft Basic ................................................ 20506

25 ft Basic ................................................ 20536

C. HW-17V (w/valve) Heliarc TIG Torch; 60° head,

12-1/2 ft; use with adapter and gas hose noted

below and TIG weld without disconnecting the MIG

torch; attach HW-17V to the adapter and run gas

hose directly to shielding gas regulator/flowmeter.

16X48

D. TIG Torch Adapter; used to attach standard

Heliarc Torch to Migmaster 300i cvcc ............

................................................................. 21223

E. Gas Hose; 12-1/2 ft, includes fittings ..................

................................................................. 40V77

F. HW-17cc Heliarc TIG Torch; 60° head, 12-1/2 ft.

16X48cc

Torch plugs into same front panel connector as the

MT-200cc; convert from MIG to TIG quickly and

have gas control through the Power Source. In-

cludes body, handle, long cap, cable, and cc

connector.

G. HC-6 Torch Control; 12-1/2 ft ................... 21225

Attach to welding torch for remote control of output

contactor.

H. FC-6 Foot Control; 12-1/2 ft ..................... 33517

Remote foot control of output and contactor.

I. Stick Electrode Holder Assembly ............. 21226

Assembly includes holder, cable, and twist lock

connector.

Table 2-4. Slide-on Nozzles

(MT-200cc & MIG-41A)

Nozzle*

Desc. I.D.

Standard

Duty

Heavy

Duty

#6 Tapered 3/8" 998895 -

#8 1/2" 998893 999471

#10 5/8" 998894 999472

#12 3/4" - 999473

#12 Spot 3/4" 17316 999625

#10 Stud 5/8" 17173 -

*Uses Nozzles Adapter P/N 999452.

2.6 SAFETY

The safety section at the front of this manual should

be read completely before attempting to install and op-

erate this equipment. Both equipment and personnel

hazards are reduced if proper safety precautions are

taken. If you are unsure of yourself in any situation,

ask your supervisor or other experienced personnel

for help.

3.2.3 CONTROL ELECTRONICS BOARD

The control electronics board (PCB1) is the command

central of the MIGMASTER 300i Power Source. It

collects information, in the form of electronic signals,

from all other operating parts of the Power Source. This

information includes the data entered at the front panel

by the operator, the signals from the torch switch, mea-

sured current and voltage, and wire feed speed.

The outputs from PCB1 controls the wire feed speed

motor (M2), the inverter power unit, the two row text

display, and the solenoid valve (SOL1).

THE CONTROL ELECTRONICS BOARD IS CON-

NECTED TO THE MAIN INPUT VOLTAGE. DO NOT

TOUCH OR OTHERWISE COME IN CONTACT WITH

THIS BOARD WHEN POWER IS APPLIED TO PRE-

VENT POSSIBLE ELECTRICAL SHOCK.

3.3 DISPLAY AND CONTROLS

3.3.1 GENERAL

The operation of the Power Source is determined by

the settings of the Process Selector Switch and the 2-

line, 32-character display screen controlled by the three

keypads located directly below the display screen.

These components are located on the front panel of

the Power Source. The keypads and display screen

(Figure 3-1) are the main communication link between

the Migmaster 300i and the operator.

Figure 3-1. Display and Keypads

UPPER LINE WITH 16 CHARACTERS

lower line with 16 characters

LEFT KEYPAD MIDDLE

KEYPAD

RIGHT KEYPAD

III. OPERATIONAL DESCRIPTION

3.1 GENERAL

This manual is intended to familiarize personnel with

the service and maintenance procedures applicable to

the MIGMASTER 300i cvcc Power Source. Informa-

tion contained in this manual should be read carefully

before performing service or maintenance tasks.

3.2 POWER SOURCE

The Power Source consists of three main components:

A. Wire feeder for MIG welding.

B. Power unit.

C. Control electronics board (PCB1) with the dis-

play and front panel keys connected to it.

The most important part is the operator. The operator

observes the welding arc and adjusts the Power Source

to give a good welding condition.

3.2.1 WIRE FEEDER

The wire feeder motor (M2) receives controlling infor-

mation from the control electronics board (PCB1).

When PCB1 initiates motor movement, the motor cir-

cuit feeds back speed information (signals) to PCB1.

The controlling circuitry on PCB1 uses these feedback

signals to maintain a set wire feed speed. This control

maintained by PCB1 ensures that the operator can

maintain desired weld formation.

The gas solenoid valve located in the wire feed com-

partment is turned ON and OFF by the control elec-

tronics board. The timing of these on and off signals

are determined by the sequencing program resident

on the control electronics board.

3.2.2 POWER UNIT

The power unit is a primary switched inverter type. It

converts the main input to a voltage and current suit-

able for welding.

The power unit's power conversion factors are con-

trolled by the control electronics board and can be

changed easily by the operator to accommodate the

three welding processes (MIG, TIG, and STICK). Ad-

ditionally, the MIG process can be tuned to accept dif-

ferent consumables in a similar manner. There is no

need for bulky variable inductors since settings of the

control electronics will make this change.

3.3.2 OPERATIONAL DESCRIPTION OF DISPLAY

The display screen presents a two-line alphanumeric

display. The upper line displays the main control func-

tion and the lower line displays the selections and set-

tings made. Additionally, the upper line indicates mea-

sured data during welding and holds this data until

changed by the keypads.

The right and left keypads are used to increase and

decrease the setting of parameters. The arrow point-

ing up on the right keypad indicates an increase in pa-

rameter value while the arrow pointing down on the left

keypad indicates a decrease in parameter value.

The keypads are also used to select between different

choices. For this operation, the right keypad selects

choices to the right as indicated by the arrow. Like-

wise, the left keypad will select choices to the left as

indicated by the arrow. The middle keypad is used to

step to the next line in a list to be changed.

Finding and setting a welding condition is an iterative

process. This means that one or more parameters

are tuned to reach a desired result. Tuning means

that the value of a parameter is changed, a test weld is

performed, and based upon the test weld results, the

operator will either change the setting or select another

parameter to tune. This process continues until a sat-

isfactory welding condition for the job is found.

To make this process effective with as few controls as

possible, all parameters are stored in a dynamic list.

The order of the parameter list is based upon whether

or not the value is changed. This will always keep the

most likely parameter to be changed accessible and

the second most likely parameter to be the next pa-

rameter to be accessed. Changing a parameter will

put that parameter line on top of the list. Not changing

the parameter will leave it in its position. This applies

only to MIG set parameters such as voltage, wire feed

speed, inductance, spot time, etc. In this way, the it-

erative process of finding a set of welding parameters

will be accelerated.

To limit the number of lines in the list, only those items

selected are present in the list. If SEL SET-UP TYPE

is "guided mode" you will find lines in the list that will

allow the operator to specify wire type, wire size, shield-

ing gas, plate size, voltage trim, and wire speed. If

"manual mode" is selected, SEL SET-UP TYPE will

disappear and the operator will find lines allowing the

setting of voltage, wire feed speed, and inductance.

When the operator starts to weld or hits the torch switch,

the top of the list is displayed. An overview of the total

setting is made by stepping down the parameter list.

(It is only possible to step down the list and set or se-

lect.) Notes may be made in the free space of the

front panel.

3.3.3 OPERATIONAL PROCEDURE OF DISPLAY

A. The upper line shows the main control func-

tion; SELect an item or SET a parameter.

B. The middle keypad advances the display to the

next line of parameters in the list. The bottom

line shows the present (active) SELection or

SETting. If this is satisfactory, and another

item is desired, press the middle keypad again.

C. If the left or right keypad is pressed, the

SELection is changed. A SET value of a

parameter is set by pressing the left (decrease)

or right (increase) keypad again. One of the

following will occur the next time the middle

keypad is pressed:

1. If other lines are dependent on the

SELection made, they will appear the next

time the middle keypad is pressed.

2. A change of a parameter that the operator

SET will put that parameter at the top of

this list the next time the middle keypad is

pressed and the list will move down a line.

The next line will be displayed (not the

second in the list). If the torch switch is

pressed instead of the middle keypad, the

changed parameter at the top of the list

will be displayed.

D. When the torch switch is pressed and/or weld-

ing starts, the display's lower line shows the

last SET item. The upper line shows measured

data (normally current and voltage).

E. After welding, the upper line returns to the main

control function text when any of the three

keypads are pressed the first time.

F. If a SET parameter is in the lower line of the

display during welding, the left (decrease) and

right (increase) keypads may be used. The two

knobs on the torch or pendant may be used to

change the parameters since they have the

same function as the left and right keypads.

3.4 FINDING WELDING PARAMETERS IN MIG

For MIG welding, the MigMaster 300i offers two meth-

ods of setting the welding conditions. The initial

SELection is made when SEL SET-UP TYPE is pre-

sented on the upper line of the display. The two meth-

ods are: guided mode and manual mode.

The "manual mode" gives the same function as con-

ventional MIG welding equipment. It allows the set-

ting of voltage, wire feed speed, and inductance. This

requires prior knowledge by the operator to know what

to set for the job being performed.

In case the operator does not know what voltage and

wire feed speed to use for the job, he may use the

"guided mode". This mode contains a built-in table

that when given wire type and size, shielding gas, and

plate size, it calculates a good starting point for wire

feed speed and voltage. From this starting point, the

operator can deviate with the TRIM line for voltage

and wire feed speed. The TRIM lines on the display

show actual values and how far from the preset val-

ues the operator has moved the actual value.

The voltage is trimmed up for longer arc length and

down for shorter arc length. Wire feed speed is

TRIMmed up for more wire feed speed and current. If

wire feed speed is TRIMmed down, the reverse will

occur. Using these two trims, it is possible for the

operator to find the ideal parameters for the job.

When wire feed speed is trimmed, the voltage is

changed on the basis of a relationship that is stored in

the control logic. This is made to maintain a constant

arc length with a change in wire feed speed to make

the effort of finding a parameter combination for the

job easier. This relationship and the combined change

is referred to as a synergic function. Refer to para-

graph 3.5.

3.5 SYNERGIC RELATIONSHIPS AND

FUNCTIONS

The selection of material is done to help the operator

set up the Power Source for operating in MIG. By de-

fining the welding consumables to be used and the

size of material to be welded, the operator receives

help from the control unit to set the welding param-

eters. The wire speed and welding voltage is preset

by the control unit as a function of the chosen

consumables and material size.

Setting of the plate thickness will have the same effect

as a coarse setting of wire feed speed. The relation-

ship between them is determined by the consumable

selection process above.

The relationships are set up as tables of wire feed speed

being a function of plate size and linear relations be-

tween wire feed speed and voltage. The relationships

will in most cases cover the short arc or the spray arc

made in MIG welding. For wire types and shielding

gases that cover both material transfer types, a switch

is made one plate size (wire feed speed) when the wire

feed speed increases and another (lower) when it is

decreased. The switch will make a change in voltage

to accommodate the change from short arc to spray

arc.

In recognizing that it is impossible to preset welding

equipment to match all possible joint configurations and

welding positions, there are two ways to fine tune the

setting: 1) With the decrease/increase keypads,

change the wire feed speed or offset the precalculated

voltage or 2) perform the same function using the re-

mote control knobs in the torch or on the pendant.

If the parameters have been set up in "guided mode"

and the SEL SET-UP TYPE is changed to "manual

mode", the voltage and wire feed speed settings, at

that time, are moved over to the manual setting of volt-

age and wire feed speed.

3.6 SERVO FUNCTIONS

Changes in the stick out of the torch on a conventional

welding power source will cause a change in welding

voltage. This is compensated for by the servo function

of the MigMaster 300i.

When the MigMaster 300i is set to a specific voltage

(in MIG), the arc voltage is monitored and maintained

by a voltage servo on the control electronics board. A

similar servo operates when the MigMaster 300i is used

for STICK welding. In this case, the welding current is

monitored and maintained to the preset value. A con-

ventional power source for STICK changes the cur-

rent when the arc length is changed.

These two servos are designed to not interfere with

the necessary "slopes" and "inductances" that are

needed for the MIG and STICK welding processes.

3.7 SAVING WELDING CONDITIONS

If a job is to be repeated at a later time, it may be de-

sired to save the welding conditions just completed.

To make this possible, the MigMaster 300i has three

lists, each containing a complete MIG setup. One of

the three lists is always active. The line SEL ACTIVE

LIST shows which list is active. If the "active list #1"

shows on the lower line of the display while scrolling

through the list, it means that the whole list is list num-

ber one.

If the Power Source is set up for a job and the operator

desires to come back to these settings later, change

the active list to number 2 or 3 with the right keypad.

Now a new set of parameters can be set up for an-

other job. Returning to the parameters of the first job

is done by stepping through the list with the middle

keypad to the upper line of SEL ACTIVE LIST and us-

ing the left keypad to SELect "active list #1".

3.8 FAULT CONDITIONS

The operating parameters of the MIGMASTER 300i

Power Source is continuously monitored without inter-

fering with the operator. The control circuit monitors

the following:

A. Main input voltage for over or under voltage

conditions.

B. Thermal switches (TS1 and TS2) and power

output to prevent Power Source overheating.

C. Wire feeder motor (M2) speed.

D. Electrical function of the inverter power unit.

In the event the monitoring activity detects any out-of-

tolerance conditions, the operation in progress is inter-

rupted and the display indicates what the problem is in

the following manner:

A. Top row shows "DETECTED A FAULT".

B. Bottom row indicates the problem.

It may be difficult to see the message on occasion due

to the function of the screen displaying the measured

values of the current welding process. The informa-

tion is easy to find because it is a line in the list and

when the operator scrolls through the list, the mes-

sage line will show up as one of the lines in the list.

When the displayed problem(s) are corrected, the mes-

sage will disappear and operation may be resumed.

Table 3-1. Parameter Defaults

In MIG process:

Top row Bottom row

SEL SET-UP TYPE

SEL WIRE TYPE

SEL WIRE SIZE

SEL GAS SHIELD

SEL PLATE SIZE

TRIM VOLTAGE

TRIM WIRE SPEED

SEL TRIGGER TYPE

SEL START TYPE

TRIM BURNBACK

SEL ACTIVE LIST

guided mode

mild steel

.035" dia.

90Ar+8C02+202

16ga .060"

14.8 +0.0 volts

125 +0ipm

continuous

normal

0.20 seconds

list #1

In TIG process:

Top row Bottom row

SET CURRENT TIG

SET PRE FLOW

SET POST FLOW

60 amps

0.5 seconds

12.0 seconds

In STICK process:

Top row Bottom row

0 Amp 51.0 Volts STICK 120 amps

The only exception to this is the fault "high current". In

this case, the Power Source will have to be shut down

(off) and a service representative contacted.

If during welding, a short circuit (i.e., frozen electrode)

is maintained longer than normal, a safety function limits

the output. Once the short is removed, the operation

will return to normal.

To display the default settings, press the left and middle

keypad and turn power switch to ON (while holding

keypads down). This action will give the default set-

ting of the lists. The complete setting of all parameter

defaults are shown in Table 3-1.

IV. INSTALLATION OF POWER SOURCE

AND ACCESSORIES

4.1 LOCATION

Several factors should be considered when selecting

an installation site. Adequate ventilation is necessary

to provide cooling, and the amount of dirt and dust to

which the machine is exposed should be minimized.

There should be at least 18 inches of unrestricted space

between the Power Source's side and rear panels and

the nearest obstruction to provide freedom of air move-

ment through the Power Source.

The installation site should permit easy removal of the

Power Source outer enclosure for maintenance. In-

stalling or placing any type of filtering device will re-

strict the volume of intake air, thus subjecting the Power

Source internal components to overheating. Warranty

is void if any type of filtering device is used.

Do not operate the machine without the running

gear installed.

4.2 ASSEMBLY OF REAR WHEELS

The unit's running gear is factory assembled except

for the rear wheels which are packed loose and in the

shipping carton. The rear gear consists of two wheels,

four washers, two cotter pins, and an axle. To install

the gear, do the following:

A. Insert the axle through the holes provided at

the rear of the gear.

B. Place a washer onto each end of the axle. Slip

on the wheels and add another washer to the

outside of each wheel. Secure the whole

assembly by inserting a pin into each end of the

axle.

C. Remove the existing shipping supports by un-

screwing from chassis.

4.3 ELECTRICAL INPUT CONNECTIONS

In order to provide a safe and convenient means to

completely remove all electrical power from the Power

Source, it is highly recommended that a line discon-

nect switch be installed in the input circuit to the Power

Source.

BEFORE MAKING ELECTRICAL INPUT CONNEC-

TIONS TO THE WELDING MACHINE, "MACHINERY

LOCKOUT PROCEDURES" SHOULD BE EM-

PLOYED. IF THE CONNECTIONS ARE TO BE

MADE FROM A LINE DISCONNECT SWITCH, THE

SWITCH SHOULD BE PADLOCKED IN THE OFF

POSITION. IF THE CONNECTION IS TO BE MADE

FROM A FUSEBOX, REMOVE THE FUSES AND

PADLOCK THE COVER CLOSED. IF NO LOCKING

FACILITIES ARE AVAILABLE, ATTACH A RED TAG

TO WARN OTHERS NOT TO ENERGIZE THE CIR-

CUIT.

4.3.1 INPUT ELECTRICAL REQUIRE-MENTS

The primary input voltage requirements are shown on

the Power Source nameplate. The Power Source is

designed to be operated from a 208/230 V single-phase

50/60 Hz power supply.

Figure 4-1. Primary Connections

4.3.2 INPUT CONDUCTOR CONNECTIONS

The input power cord is provided with an attachment

plug. The plug will mate with a 250 Volt, 50 Amp re-

ceptacle conforming to NEMA 6-50R configuration.

The receptacle should be wired to a separately fused

disconnect or circuit breaker. This disconnect or

breaker can be wired to a single-phase system or to

two conductors of a three-phase system. A third con-

ductor for grounding should also be connected between

the disconnect and the receptacle.

THE TERMINAL LABELED GRD IS CONNECTED TO

THE POWER SOURCE CHASSIS AND IS FOR

GROUND PURPOSES ONLY. IT MUST BE CON-

NECTED TO A GOOD ELECTRICAL GROUND. DO

NOT CONNECT A CONDUCTOR FROM THE TER-

MINAL LABELED GRD TO ANY ONE OF THE L1

OR L2 TERMINALS AS THIS WILL RESULT IN AN

ELECTRICALLY HOT WELDING MACHINE CHAS-

SIS.

Figure 4-2. Voltage Changeover Terminal

Board

Figure 4-3. Controls and Welding Cable Connections

POWER CORD

GAS

HOSE

TORCH

CONNECTOR

(RECEPTACLE

(J4)

ELECTRODE

CABLE

ELECTRODE

-(J6) AND

+ (J5) OUTPUT

RECEPTACLES

4.4 SECONDARY OUTPUT CONNECTIONS

The Migmaster 300i Power Source is completely self-

contained so that the front panel torch fittings are in-

ternally connected to the welding polarity (dc reverse

or dc straight) via the secondary output terminals. The

Power Source comes set up for DCRP welding.

BE SURE THE BRANCH CIRCUIT OR MAIN DIS-

CONNECT SWITCH AND MIGMASTER POWER

SWITCH (FIGURE 4-3) IS OFF OR ELECTRICAL

INPUT CIRCUIT FUSES ARE REMOVED BEFORE

MAKING OR CHANGING SECONDARY CONNEC-

TIONS ON THE MIGMASTER 300i. BE SURE THAT

WIRE, TORCH, STICK OR ELECTRODE HOLDER

IS NOT TOUCHING WORKPIECE WHEN INITIALLY

APPLYING POWER.

P12

CONTROL

DISPLAY

SCREEN

MIG

TIG

STICK

POWER

SWITCH

MIG-41A

POWER

LEAD

CONNECTOR

PROCESS

SELECTOR

SWITCH

Migmaster 300i

The MigMaster 300i is capable of MIG, TIG, and STICK

welding processes. It is designed to connect and dis-

connect a MIG Torch, TIG Torch, and a STICK elec-

trode holder quickly and safely.

As shown in Figure 4-3, the MigMaster 300i has posi-

tive (J5) and negative (J6) ELECTRODE output recep-

tacles for output power.

The torch polarity cable is hardwired internally to torch

connector receptacle J4 (located in wire feed compart-

ment). This internal connection and the ELECTRODE

receptacle (- or +) that the torch polarity cable plug

(P12) is connected to, determine the welding polarity.

For example; by connecting P12 to the negative (-)

ELECTRODE output receptacle (J6), the torch con-

nected at J4 will be welding with straight dc polarity.

By connecting P12 to the positive (+) ELECTRODE

output receptacle (J5), the torch will be welding with

reverse dc polarity. The latter polarity (reverse) is the

most commonly used way to weld with the MIG pro-

cess.

4.5 WELDING CABLE CONNECTIONS (WORK

CABLE)

Connect the plug of the work cable to the ELECTRODE

output connector not being used. Connect the work

clamp solidly to the workpiece on work table. Clamp

onto a bare metal area.

A GOOD ELECTRICAL CONNECTION TO THE

WORK IS ESSENTIAL TO PROPER WELDING OP-

ERATION AND TO PREVENT ELECTRIC SHOCK.

Welding cables should be kept as short as possible

and be of adequate current carrying capacity. Resis-

tance of the welding cables and connections causes a

voltage drop which is added to the voltage drop of the

arc. Excessive cable resistance may result in a re-

direction of the maximum usable current output of the

equipment.

The proper operation of this equipment is to a large

extent dependent on the use of welding cables and

connections which are in good condition and of ad-

equate size.

4.6 INSTALLATION FOR MIG WELDING

BE SURE THE BRANCH CIRCUIT OR MAIN DIS-

CONNECT SWITCH AND MIGMASTER POWER

SWITCH (FIGURE 4-3) IS OFF OR ELECTRICAL

INPUT CIRCUIT FUSES ARE REMOVED BEFORE

MAKING OR CHANGING SECONDARY CONNEC-

TIONS ON THE MIGMASTER 300i. BE SURE THAT

WIRE AND/OR TORCH IS NOT TOUCHING

WORKPIECE WHEN INITIALLY APPLYING POWER.

4.6.1 TORCH CONNECTION (MT-200CC)

The MT-200cc Torch is supplied as standard equip-

ment with the MigMaster 300i Power Source.

To connect the MT-200cc Torch to the Power Source,

line up the connector of the torch cable with matching

holes in Power Source connector receptacle J4 (Fig-

ure 4-3). Insert torch cable plug and tighten the lock-

ing collar.

4.6.2 TORCH POLARITY CABLE AND WORK

CABLE (FIGURE 4-4)

For welding mild steel, stainless steel, and aluminum

using cored wires, connect plug P12 to the ELEC-

TRODE positive (+) output receptacle (J5) on Power

Source. Connect the work cable plug to the ELEC-

TRODE negative (-) output receptacle (J6) as described

in paragraph 4.5. The connection setup described will

give dc reverse polarity welding. In addition to Figure

4-4, refer to the MIG connection illustration on the front

of the Power Source in the MIG block.

Figure 4-4. MIG Connections

For some cored wires the torch needs to be connected

for straight dc polarity welding. To make this connec-

tion setup, connect plug P12 to the ELECTRODE nega-

tive (-) output receptacle (J6) and the work cable plug

to the ELECTRODE positive (+) output receptacle (J5)

as described in paragraph 4.5. After making the de-

sired polarity welding connections, place Process Se-

lector Switch (Figure 4-3) to the MIG position. Refer to

Section V for operational instructions.

P12

4.6.3 WIRE FEEDER MECHANISM

4.6.3.1 DRIVE ROLLS (FIGURE 4-5)

The drive roll has two grooves: the small groove feeds

0.035 in. diameter wire, the large groove feeds 0.045

in. wire. The groove nearest the gear motor feeds the

wire. If the required groove is not correctly positioned,

perform the following:

A. Release the pressure drive roll lever and lift the

assembly upward.

B. Remove the two (2) screws holding the drive

roll to the gear.

C. Reverse the drive roll on the drive roll shaft.

D. Replace the screws and tighten.

E. Secure the pressure drive roll assembly.

Figure 4-5. Wire Feeder Mechanism

4.6.3.2 WELDING WIRE SPOOL

AS WITH ANY WORK AREA, MAKE SURE SAFETY

GLASSES WITH SIDE SHIELDS ARE WORN WHEN

HANDLING OR CHANGING WIRE OR CLIPPING

WIRE OFF AT THE SPOOL OR AT THE END OF THE

TORCH. HOLD ONTO THE WIRE COMING OFF THE

SPOOL WITH ONE HAND BEFORE CLIPPING. SE-

RIOUS EYE INJURY CAN RESULT DUE TO THE RE-

SILIENCE OF THE WIRE WHICH CAN QUICKLY UN-

RAVEL, OR A CUT WIRE END WHICH MAY SHOOT

ACROSS THE ROOM.

Install a spool of welding wire on the hub as follows:

A. Unscrew spool nut from hub.

B. Place wire spool on hub to rotate clockwise as

wire is unwound; hub pin must engage hole in

spool.

C. Install spool nut.

4.6.3.3 THREADING WELDING WIRE

A. Turn off power switch.

WHEN THE POWER SWITCH IS ON, AND GUN

TRIGGER IS DEPRESSED, THE ELECTRODE WIRE

BECOMES ELECTRICALLY HOT, AND THE WIRE

FEED ROLLS ARE ACTIVATED.

B. Release pressure drive roll assembly and lift

upward. Check that proper wire diameter

groove is in the inner position.

Before threading welding wire through liner, make

sure chisel point and burrs have been removed

from wire end to prevent wire from jamming in gun

or liner.

C. Feed the wire from the spool through the inlet

guide, across the drive roll groove and into gun

outlet guide.

Make sure that the proper "outlet guide tube" is inserted

into the front-panel gun fitting for the size and type of

wire being used, see Table 2-3 for wire feed accesso-

ries.

To ensure proper wire feeding, it is important that the

wire be kept clean and that the drive rolls be periodi-

cally cleaned of any chips or scale that might be car-

ried into the gun liner and cause sticking.

D. Lower pressure roll assembly and secure.

Check that the gears mesh. Feed wire through

to gun tip using the inch/purge switch.

4.6.3.4 BRAKE DRAG ADJUSTMENT

Brake disc friction should provide enough drag to keep

the wire spool or core from spinning freely after wire

feed stops. If adjustment is required, turn adjusting

screw clockwise to increase drag, counterclockwise to

decrease it. Drag should be just low enough to limit

wire overrun.

4.7 CONNECTION OF SHIELDING GAS

SUPPLY

The R-50-FM regulator is an adjustable regulator de-

signed for use with Argon, Helium, Nitrogen, and C-25

(75% argon/25% CO

) gas service. The following chart

provides the recommended flow ranges of the R-50-

FM-500 regulator.

Argon 10-40 CFH

Helium 25-125 CFH

Nitrogen 10-50 CFH

C-25 10-40 CFH

4.7.1 GAS SHIELDING SUPPLY

A. With the cylinder cap in place, CAREFULLY

slide the cylinder of gas onto the MigMaster

300i cylinder rack.

B. Secure the cylinder to the unit, using the chain

provided.

C. Unscrew the cylinder cap.

4.7.2 CONNECTION

DO NOT CLAMP REGULATOR CAP IN A VISE OR

GRIP IT WITH A PAIR OF PLIERS. DISTORTION

OF CAP CAN JAM THE INTERNAL PARTS AND

CAUSE EXCESSIVELY HIGH DELIVERY PRES-

SURE AS WELL AS WEAKEN THE THREADED

JOINT TO THE REGULATOR BODY. THIS MAY

CAUSE CAP TO FLY OFF AND POSSIBLY INJURE

PERSONNEL IN AREA.

A. Open the cylinder valve slightly, for an instant,

to blow out any dust or dirt that may have

collected in the valve outlet. BE SURE to keep

your face away from the valve outlet to protect

your eyes.

B. Attach the regulator to the cylinder valve. Align

the regulator so that the flowmeter is vertical

and then tighten the connection nut with a 1-1/

8 in. open end wrench or an adjustable wrench.

(To prevent damaging the O-ring seals and

plastic tube, do not use the flowmeter tube as

a 'handle' when attaching the regulator.)

Figure 4-6. R-50 Regulator

C. Make sure that the flow control valve on the

flowmeter is closed.

D. Attach the gas hose from the rear of the Mig-

master 300i to the regulator outlet connection.

NEVER STAND DIRECTLY IN FRONT OF OR BE-

HIND THE REGULATOR WHEN OPENING THE CYL-

INDER VALVE. ALWAYS STAND TO ONE SIDE.

E. Open the cylinder valve SLOWLY a fraction of

a turn. This will prevent damage to gauge and

critical components in the regulator. When the

gauge needle stops moving, then open the

cylinder valve fully.

4.7.3 REGULATING FLOW

Flow is controlled by adjusting the flowmeter valve un-

til desired flow is indicated by the ball float in the flow-

meter tube. Always take the reading across the TOP

of the ball.

Using a leak test solution, such as P/N 998771 (8 oz.

ctr) or soapy water, test for leakage about the cylinder

valve stem, the regulator inlet connection, and the hose

connections at the regulator and at the Migmaster 300i

for leakage. Correct any leaks before starting work.

4.7.4 STOPPING WORK

If work is to be stopped for a half-hour or more, the

regulator is to be removed from the cylinder, shut down

the regulator as follows:

A. Close the cylinder valve.

B. Release gas from the regulator by closing the

torch trigger lever.

C. When pressure gauge drops to zero, the regu-

lator is depressurized and shut down.

Each regulator is equipped with a porous metal inlet

filter, P/N 71233, pressed into the regulator input nipple.

No regulator should be connected to a cylinder or sta-

tion valve unless it contains this filter. You can replace

the filter if necessary. Refer to the regulator instruc-

tion literature for details.

Regulators in need of repair should be returned to your

welding equipment distributor or to an authorized

remanufacturing center. For a detailed description of

the regulator, refer to the R-50-FM-580 Regulator-Flow-

meter instruction Manual, F-14-238.

IF WELDING IS PERFORMED IN A CONFINED

AREA, SHIELDING GAS LEAKS COULD RESULT

IN A BUILDUP OF SHIELDING GAS CONCENTRA-

TION DISPLACING OXYGEN, THEREBY ENDAN-

GERING PERSONNEL ENTERING THE AREA.

4.8 MIG-41A PUSH-PULL GUN

The MIG-41A push-pull gun combines with the Mig-

master 300i to create a high performance push-pull

system. The MIG-41A synchronizes with the wire

feeder, providing an ideal means for feeding small di-

ameter wires long distance.

The MIG-41A connects to the front panel of the Mig-

master 300i. The inlet connector of the MIG-41A is

inserted into the common connector and the power lead

plugs into the MIG-41A connector in the center of the

front panel.

For a detailed description of the MIG-41A, refer to the

MIG-41A Push-Pull Gun Instruction Manual, F-14-497.

4.9 INSTALLATION FOR TIG WELDING

BE SURE THE BRANCH CIRCUIT OR MAIN DIS-

CONNECT SWITCH AND MIGMASTER POWER

SWITCH (FIGURE 4-3) IS OFF OR ELECTRICAL

INPUT CIRCUIT FUSES ARE REMOVED BEFORE

MAKING OR CHANGING SECONDARY CONNEC-

TIONS ON THE MIGMASTER 300I. BE SURE THAT

TORCH COMPONENTS ARE NOT TOUCHING

WORKPIECE WHEN INITIALLY APPLYING POWER.

BE SURE THAT GAS CYLINDER VALVE IS CLOSED

TO PREVENT GAS FROM BEING PRESENT WHEN

INITIALLY APPLYING POWER.

The Migmaster 300i Power Source is not designed

for High Frequency starts of any kind. Do not con-

nect any component using this method to the Mig-

master 300i to prevent possible destruction of the

Power Source.

4.9.1 USING THE TORCH WITH CENTRAL CON-

NECTOR (FIGURE 4-3 AND 4-4)

If the MigMaster 300i is currently set up for MIG

welding, the MIG Torch must be removed and

the wire retracted and fastened on the spool.

This is done to prevent the MIG wire from

electrically contacting the output while TIG

welding.

A. If necessary, remove MIG torch and retract

wire (use precautions outlined in paragraph

4.6.3).

B. Connect plug P12 to ELECTRODE negative

(-) output receptacle (J6).

C. Connect plug of Work lead to ELECTRODE

positive (+) output receptacle (J5).

D. Connect the correct shielding gas for the

material being welded (i.e., pure argon for

aluminum, stainless steel, and mild steel).

Refer to paragraph 4.7 for making connec-

tions.

E. Set the Process Selector Switch (Figure 4-3)

to the TIG position. The MigMaster 300i is

now set for TIG welding with dc straight

polarity. If dc reverse polarity is required,

connect plug P12 to the ELECTRODE posi-

tive (+) output receptacle (J5) and the plug of

the Work lead to the negative (-) output recep-

tacle (J6). Refer to Section V for operational

instructions.

4.9.2 USING TIG TORCH WITH GAS VALVE ON

In this setup, the TIG Torch is connected for dc straight

polarity welding. The shielding gas is connected di-

rectly from the gas regulator to the torch connector

(J4). The gas valve located in the MigMaster 300i is

not used in this setup; however, if another gas bottle

is connected, its valve must be closed. The plug of

the Work lead is, in this setup, connected to the ELEC-

TRODE positive (+) output receptacle (J5). Refer to

Section V for operational instructions.

4.10 INSTALLATION FOR STICK WELDING

BE SURE THE BRANCH CIRCUIT OR MAIN DIS-

CONNECT SWITCH AND MIGMASTER POWER

SWITCH (FIGURE 4-3) IS OFF OR ELECTRICAL IN-

PUT CIRCUIT FUSES ARE REMOVED BEFORE

MAKING OR CHANGING SECONDARY CONNEC-

TIONS ON THE MIGMASTER 300I. BE SURE THAT

STICK OR ELECTRODE HOLDER IS NOT TOUCH-

ING WORKPIECE WHEN INITIALLY APPLYING

POWER.

A. Connect plug of the stick electrode holder

cable to the ELECTRODE positive (+) output

receptacle (J5).

B. Connect plug of Work lead to the ELECTRODE

negative (-) output receptacle (J6).

C. Unplug (if connected) plug P12. Plug P12 will

remain unplugged for this setup.

D. Set the Process Selector Switch (Figure 4-3) to

the STICK position.

The MigMaster 300i is now connected for dc reverse

polarity STICK welding.

If dc straight polarity STICK welding is required, con-

nect the plug of the electrode holder cable to the ELEC-

TRODE negative (-) output receptacle (J6) and the plug

of the Work lead to the ELECTRODE positive (+) out-

put receptacle (J5). Refer to Section V for operational

instructions.

NOTE

The TIG or MIG Torch may be left connected to the

Torch connector (J4) during STICK welding if the

stick is installed as described above.

4.11 SWITCHING BETWEEN PROCESSES

A potentially dangerous situation could exist with parts

being exposed to welding electrical potentials without

the user being aware of it.

The Process Selection Switch (Figure 4-3) makes it

easy to change between the different weld processes;

however, the user must remember to reconnect the

tools to the output properly for each process. If this is

done with main power disconnected, as indicated by

the warnings at the beginning of each paragraph, and

according to the instructions given above, no problems

should occur.

The MigMaster 300i is not designed to have all combi-

nations of torches hooked up at the same time, the

hookups and the Process Selection Switch controls the

operation.

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ESAB Migmaster 300i cvcc Welding Power Supply User manual

Brand: ESAB

Model: Migmaster 300i cvcc Welding Power Supply

Category: Welding System

Type: User manual

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ESAB Migmaster 300i cvcc Welding Power Supply User manual

ESAB Migmaster 300i cvcc Welding Power Supply User manual

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