Miller Electric AEAD-200-LE User Manual

February 1996

Form: TM-428

Effective With Serial No. JH242114

TECHNICAL MANUAL

Service And Parts

Miller Legend

(Formerly The Legend AEAD-200LE)

CC AC/DC Welding Generator For SMAW, GMAW, GTAW Welding

	Welding	Weld	Rated	Maximum	Auxiliary Power
		Output	Welding	Open-Circu		Fuel Capacity	Engine
	Mode				Rating
		Range	Output	it Voltage
			225 A, 25 V,		Single-Phase,
	CC/AC	35 ± 225 A	100% Duty	80	5 kVA/kW, 42/21 A,		Onan P218 Air-Cooled,
			Cycle		120/240 V AC, 60 Hz
					And	7.5 gal (28 L) Tank	Two-Cylinder, Four-Cycle,
			200 A, 25 V,		Single-Phase,		Gasoline Engine
	CC/DC	25 ± 200 A	100% Duty	72	1 kVA/kW, 9 A,
			Cycle		115 V AC, 100 Hz
	cover_tm 4/95 ± ST-140 091-E			1996	MILLER Electric Mfg. Co.		PRINTED IN USA

TABLE OF CONTENTS

SECTION 1 ± SAFETY PRECAUTIONS FOR SERVICING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		1
1-1.	Symbol Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1
1-2.	Servicing Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1
1-3.	EMF Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	2
SECTION 2 ± INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		3
2-1.	Installing Welding Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	3
2-2.	Dimensions, Weights, And Operating Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	3
2-3.	Fuel Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
2-4.	Engine Prestart Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
2-5.	Connecting The Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
2-6.	Connecting To Weld Output Terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
2-7.	Selecting Weld Cable Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
2-8.	Remote 14 Receptacle RC1 Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
SECTION 3 ± OPERATING WELDING GENERATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		7
3-1.	Front Panel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
3-2.	Remote Control (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
3-3.	Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
3-4.	Volt-Ampere Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	9
SECTION 4 ± OPERATING AUXILIARY EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		10
4-1.	100 Hz Auxiliary Power Receptacle And Circuit Breaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	10
4-2.	AC Auxiliary Power Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	10
4-3.	60 Hz Auxiliary Power Receptacles And Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . .	11
SECTION 5 ± THEORY OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		12
SECTION 6 ± TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		15
6-1.	Troubleshooting Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
6-2.	Troubleshooting Circuit Diagram For Welding Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
6-3.	Troubleshooting Circuit Diagram For Welding Generator With Optional Remote Control . .	20
6-4.	Waveforms For Sections 6-2 And 6-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	22
6-5.	Idle Control Board/Module PC1 Testing Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	23
6-6.	Troubleshooting Flowcharts For Idle Control Board/Module PC1 . . . . . . . . . . . . . . . . . . . . . .	24
6-7.	Voltage Regulator Board PC2 Testing Information Prior To Serial No. KE604176 . . . . . . . .	26
6-8.	Voltage Regulator Board PC2 Test Point Values Prior To Serial No. KE604176 . . . . . . . . .	26
6-9.	Voltage Regulator Board PC2 Testing Information Effective With Serial No. KE604176 . . .	27
6-10.	Voltage Regulator Board PC2 Test Point Values Effective With Serial No. KE604176 . . . .	27
6-11.	Optional Remote Control Board PC3 Testing Information . . . . . . . . . . . . . . . . . . . . . . . . . . . .	28
6-12.	Optional Remote Control Board PC3 Test Point Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	28
6-13.	Optional Remote Capacitor Board PC5 Testing Information Effective With
	Serial No. KD346698 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29
6-14.	Optional Remote Capacitor Board PC5 Test Point Values Effective With
	Serial No. KD346698 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29
6-15.	Replacing Brushes And Cleaning Slip Rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	30
6-16.	Checking Unit Output After Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	32

WHO DO I CONTACT FOR HELP?

H CALL:

H FAX:

H WRITE:

Miller Customer Service

800-637-2348 (in USA),

Miller Electric Mfg. Co.

Department at

or

P.O. Box 1079

414-735-4505

414-735-4136 (outside USA)

Appleton, WI 54912 USA

Always provide Model Name and Serial or Style Number

OM-428N 1/96 ± SPM-428C 6/94

SECTION 7 ± DISASSEMBLY AND REASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		33
7-1.	Disassembly Of Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	33
7-2.	Disassembly Of Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	34
SECTION 8 ± MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		35
8-1.	Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	35
8-2.	Maintenance Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	36
8-3.	Servicing Air Cleaner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	37
8-4. Changing Engine Oil, Oil Filter, And Fuel Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		38
8-5.	Adjusting Engine Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	39
8-6.	Overload Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	40
8-7. Inspecting And Cleaning Optional Spark Arrestor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		40
SECTION 9 ± ELECTRICAL DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		41
SECTION 10 ± PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		51

SECTION 1 ± SAFETY PRECAUTIONS FOR SERVICING

safety_rtm1 4/95

1-1. Symbol Usage

Means Warning! Watch Out! There are possible hazards with this procedure! The possible hazards are shown in the adjoining symbols.

Y Marks a special safety message.

. Means NOTE; not safety related.

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

1-2. Servicing Hazards

WARNING

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.

Only qualified persons should service, test, maintain, and repair this unit.

During servicing, keep everybody, especially children, away.

ELECTRIC SHOCK can kill.

1.Do not touch live electrical parts.

2.Stop engine before testing or repairing unit unless the procedure specifically requires an energized unit.

3.Insulate yourself from ground by standing or working on dry insulating mats big enough to prevent contact with the ground.

4.Do not leave live unit unattended.

5.When testing live unit, use the one-hand method.

Do not put both hand inside unit. Keep one hand free.

MOVING PARTS can cause injury.

1.Keep away from moving parts such as fans, belts, and rotors.

2.Have only qualified people remove guards or covers for maintenance and troubleshooting as necessary.

3.Keep hands, hair, loose clothing, and tools away from moving parts.

4.Before working on generator, remove spark plugs or injectors to keep engine from kicking back or starting.

5.Block flywheel so that it will not turn while working on generator components.

6.Reinstall panels or guards and close doors when servicing is finished and before starting engine.

FLYING PIECES OF METAL or DIRT can cause injury.

1.Always wear safety glasses with side shields or face shield during servicing.

2.Be careful not to short metal tools, parts, or wires together during testing and servicing.

STATIC ELECTRICITY can damage parts on circuit boards.

1.Put on grounded wrist strap BEFORE handling boards or parts.

2.Use proper static-proof bags to store, move, or ship PC boards.

ENGINE EXHAUST GASES can kill.

1.Do not breathe exhaust fumes.

2.Use in open, well-ventilated areas, or vent exhaust outside and away from any building air intakes.

ENGINE FUEL can cause fire or explosion.

1.Stop engine before fueling.

2.Do not fuel while smoking or near sparks or flames.

3.Do not overfill tank; clean up any spilled fuel.

BATTERY EXPLOSION can BLIND and INJURE.

1.Always wear a face shield when working on a battery.

2.Stop engine before disconnecting or connecting battery cables.

3.Do not allow tools to cause sparks when working on a battery.

4.Do not use welder to charge batteries or jump start vehicles.

5.Observe correct polarity (+ and ±) on batteries.

BATTERY ACID can BURN SKIN.

1.Do not tip.

2.Replace damaged battery.

3.Flush eyes and skin immediately with water.

STEAM AND PRESSURIZED HOT COOLANT can burn face, eyes, and skin.

1.Check coolant level when engine is cold to avoid scalding.

2.If the engine is warm and checking is needed, follow steps 3 and 4.

3.Wear safety glasses and gloves and put a rag over cap.

4.Turn cap slightly and let pressure escape slowly before completely removing cap.

FALLING EQUIPMENT can cause serious personal injury and equipment damage.

1.Use equipment of adequate capacity to lift components.

2.Use a lifting eye to lift unit only, NOT running gear, gas cylinders, or any other accessories.

3.Securely attach components to lifting equipment.

Miller Legend

TM-428 Page 1

	HOT PARTS can cause severe burns.					HIGH-FREQUENCY RADIATION can
	1.	Allow cooling period before servicing.				interfere with radio navigation, safety
	2.	Wear protective gloves and clothing when working				services,		computers,	and
		on a hot engine.				communications equipment.
	ELECTRIC		SHOCK	HAZARD	from	1.	Have only qualified persons familiar with
							electronic equipment perform this installation.
	incorrect use of test equipment.					2.	The user is responsible for having a qualified
	1.	Stop engine before making or changing meter					electrician promptly correct any interference
		lead connections.					problem resulting from the installation.
	2.	At least one meter lead should be a self-retaining				3.	If notified by the FCC about interference, stop
		spring clip such as an alligator clamp.
							using the equipment at once.
	3.	Read instructions for test equipment.
						4.	Have the installation regularly checked and
	MAGNETIC		FIELDS	FROM	HIGH
							maintained.
	CURRENTS		can affect pacemaker			5.	Keep high-frequency source doors and panels
	operation.						tightly shut, keep spark gaps at correct setting,
	1.	Pacemaker wearers keep away from servicing					and use grounding and shielding to minimize the
		areas until consulting your doctor.					possibility of interference.
	UNCONTROLLED TILTING OR TIPPING					READ INSTRUCTIONS.
	OF UNIT can result in personal injury
	and equipment damage.					1.	Use MILLER Testing Booklet (Part No. 150 853)
	1.	Do not put any body part under unit while lifting.					when servicing this unit.
	2.	Use adequate blocks to support components as				2.	Consult the Owner's Manual for welding safety
		needed during job.					precautions.
	PINCH POINTS can injure.					3.	Use only genuine MILLER replacement parts.
	1.	Be careful when working on stator and rotor				4.	Reinstall injectors and bleed air from fuel system
		assemblies.					according to engine manual.

1-3. EMF Information

	Considerations About Welding And The Effects Of Low Frequency	To reduce magnetic fields in the workplace, use the following
	Electric And Magnetic Fields	procedures:
	The following is a quotation from the General Conclusions Section	1.	Keep cables close together by twisting or taping them.
	of the U.S. Congress, Office of Technology Assessment, Biological
	Effects of Power Frequency Electric & Magnetic Fields ±	2.	Arrange cables to one side and away from the operator.
	Background Paper, OTA-BP-E-53 (Washington, DC: U.S.
	Government Printing Office, May 1989): ª. . . there is now a very	3.	Do not coil or drape cables around the body.
	large volume of scientific findings based on experiments at the	4.	Keep welding power source and cables as far away as
	cellular level and from studies with animals and people which clearly
	establish that low frequency magnetic fields can interact with, and		practical.
	produce changes in, biological systems. While most of this work is of	5.	Connect work clamp to workpiece as close to the weld as
	very high quality, the results are complex. Current scientific
	understanding does not yet allow us to interpret the evidence in a		possible.
	single coherent framework. Even more frustrating, it does not yet	About Pacemakers:
	allow us to draw definite conclusions about questions of possible
	risk or to offer clear science-based advice on strategies to minimize	The above procedures are also recommended for pacemaker
	or avoid potential risks.º	wearers. Consult your doctor for complete information.

TM-428 Page 2

Miller Legend

SECTION 2 ± INSTALLATION

2-1. Installing Welding Generator

Movement	Airflow	Location
Y Do Not Lift Unit From End		18 in
		(460 mm)
		18 in
	18 in	(460 mm)
	(460 mm)	OR
OR
	18 in	18 in
		(460 mm)
	(460 mm)

Grounding

	1	3
		4
		GND/PE
		OR

	Electrically bond generator frame to
2	vehicle frame	by metal-to-metal
	contact.	2

1Generator Base

2Metal Vehicle Frame

3Equipment Grounding Terminal

4Grounding Cable

Use #10 AWG or larger insulated copper wire.

YIf unit does not have GFCI receptacles, use GFCI-pro- tected extension cord.

install1 10/95 ± Ref. ST-800 652 / Ref. ST-800 477-A / ST-158 936-A / S-0854

2-2. Dimensions, Weights, And Operating Angles

A

Dimensions

Height

31-5/8 in (803 mm)

Width

18 in (457 mm)

Depth

45 in (1143 mm)

B

A

16-1/2 in (419 mm)

B

32-3/4 in (832 mm)

C

13/16 in (21 mm) Dia.

Weight

C

Net

559 lb (254 kg)

Engine End

Ship

600 lb (272 kg)

YDo not exceed operating angles while running or engine damage will occur.

YDo not move or operate unit where it could tip.

25°

25°	25°

25°

Miller Legend

TM-428 Page 3

2-3. Fuel Consumption

		SB-115 572
2-4. Engine Prestart Checks
		Check all fluids daily. Engine must
		be cold and on a level surface.
	1/2 in	Engine stops if oil pressure gets
		too low.
	(13 mm)
		Full
		Full
		ST-140 091-E / Ref. ST-151 983
TM-428 Page 4		Miller Legend

2-5. Connecting The Battery

Y Connect (±) cable last.

+ ±

Tools Needed:

3/8, 1/2 in

Ref. ST-144 839-F / Ref. ST-168 046 / Ref. S-0756-D

2-6. Connecting To Weld Output Terminals

Y Use ONLY one set of terminals at a time. Disconnect weld cables from set of weld output terminals not in use.

Tools Needed:

3/4 in

ST-140 092-B / Ref. ST-168 046

Miller Legend

TM-428 Page 5

2-7. Selecting Weld Cable Sizes

		Total Cable (Copper) Length In Weld Circuit Not Exceeding
	100 ft (30 m) Or Less		150 ft	200 ft	250 ft	300 ft		350 ft	400 ft
			(45 m)	(60 m)	(70 m)	(90 m)		(105 m)	(120 m)
Welding	10 ± 60%	60 ± 100%			10 ± 100% Duty Cycle
Amperes	Duty Cycle	Duty Cycle
100	4	4	4	3	2	1		1/0	1/0
150	3	3	2	1	1/0	2/0		3/0	3/0
200	3	2	1	1/0	2/0	3/0		4/0	4/0
250	2	1	1/0	2/0	3/0	4/0		2-2/0	2-2/0
300	1	1/0	2/0	3/0	4/0	2-2/0		2-3/0	2-3/0
350	1/0	2/0	3/0	4/0	2-2/0	2-3/0		2-3/0	2-4/0
Weld cable size (AWG) is based on either a 4 volts or less drop or a current density of at least 300 circular mils per ampere.									S-0007-D

2-8. Remote 14 Receptacle RC1 Information

				Socket*	Socket Information
				A	Contact closure to B completes 15 volts dc contactor control
					circuit.
				B	15 volts dc.
				C	+4.5 volts dc output to remote control.
A	K	J	A	D	Remote control circuit common.
B		I
C L	N	H		E	0 to +4.5 volts dc input command signal from remote control.
D	M	G
	E	F		K	Chassis common.
		ST-140 092-B

*The remaining sockets are not used.

TM-428 Page 6

Miller Legend

SECTION 3 ± OPERATING WELDING GENERATOR

3-1. Front Panel Controls

5

6

1

2

7

3

4

Using Idle Lock Switch

RUN/IDLE
LOCK	1860 rpm
	(Power/Idle)
RUN/IDLE	No Load:
	1860 rpm
	(Power/Idle)
UNLOCK	Load:
	3000 rpm
	(Weld)
RUN
OR	3000 rpm
	(Weld)
UNLOCK	LOCK

Ref. ST-168 046

1 Engine Control Switch S2

Use switch to start engine, select speed, and stop engine. In Run/Idle position, engine runs at power/idle rpm at no load, and weld/power rpm under weld or 100 Hz auxiliary power receptacle load. In Run position, engine runs at weld rpm.

2 Idle Lock Switch S1

Use switch to lock engine at power/idle speed (see Table). In Unlock position, Engine Control switch and optional Remote Control switch determine engine speed.

3 Engine Choke Control

Use control to change engine air-fuel mix.

To Start: pull out choke and turn Engine

Control switch to Start position. Release switch and slowly push choke in when engine starts. Do not crank engine while flywheel is turning.

To Stop: turn Engine Control switch to Off position.

4 Remote Control Switch S4

Use switch to select front panel or remote amperage control (see Section 3-2).

5 Ampere Ranges Switch S5

Use switch to select weld amperage range.

.For best arc starts, use lowest amperage range possible.

6 Fine Amperage Control R1

Use control to select weld amperage within the range selected by the Ampere Ranges switch. Control may be adjusted while welding. Scale is for reference only. Weld output would be 88 A DC with control settings as shown (50% of 70 to 105 A).

7 Engine Hour Meter HM

Miller Legend

TM-428 Page 7

3-2. Remote Control (Optional)
				Y Weld output terminals are
				energized	when	Remote
			1	Control switch S4 is in Pan-
				el/On position and engine is
				running.
				1 Remote 14 Receptacle RC1
				Connect optional remote control to
				RC1 (see Section 2-8).
				In Example:
				Min = 70 A DC
				Percentage Of Range = 50%
				Max = 88 A DC (50% of 70 to 105)
				Max (88 A DC)
				Min (70 A DC)
	Set Switch	Set Range	Set Percentage	Adjust Remote Control
						ST-140 092-B
3-3.	Duty Cycle
				Duty cycle is the percentage of 10
				minutes that unit can weld at rated
				load without overheating.
				Y Exceeding	duty cycle can
				damage unit and void war-
				ranty.

100% Duty Cycle at 225 Amperes AC

Continuous Welding

SB-115 570

TM-428 Page 8

Miller Legend

3-4. Volt-Ampere Curves

The volt-ampere curves show the minimum and maximum voltage and amperage output capabilities of the welding generator. Curves of other settings fall between the curves shown.

SB-115 529-A / SB-115 528-A

Miller Legend

TM-428 Page 9

SECTION 4 ± OPERATING AUXILIARY EQUIPMENT

4-1. 100 Hz Auxiliary Power Receptacle And Circuit Breaker

		Y Do not operate 50/60 Hz or
		60 Hz equipment from 100
		Hz receptacle.
		1 115 V 9 A 100 Hz AC Recep-
		tacle RC4
		Receptacle supplies single-phase
		power at weld speed only. Total
		output available is 1 kVA/kW.
		2 Circuit Breaker CB3
		CB3 protects receptacle from
	2	overload. If CB3 opens, receptacle
		does not work.

1

Ref. ST-168 046

4-2. AC Auxiliary Power Curve

SB-115 571

TM-428 Page 10

Miller Legend

4-3. 60 Hz Auxiliary Power Receptacles And Circuit Breakers

For 60 Hz		For 60 Hz
Auxiliary Power		Auxiliary
While Welding		Power Only
	LOCK	UNLOCK
	RUN/IDLE	RUN/IDLE
4
0	100	0	100
PANEL		PANEL
	ON		ON

1	5	2	6	3	7	8
				9		Ref. ST-168 046

YIf unit does not have GFCI receptacles, use GFCI-protected extension cord.

1120 V 15 A AC Duplex Receptacle RC1

2120 V 15 A AC Duplex Receptacle RC2

3240 V 30 A Twistlock Receptacle RC3

Receptacles supply 60 Hz single-phase power at power/idle speed only. Maximum output from each duplex receptacle is is 2.5 kVA/kW. Maximum output from twistlock receptacle is 5 kVA/kW. For 60 Hz auxiliary power, set controls as shown in table.

4120 V 15 A AC Duplex GFCI Receptacles GFCI1 And GFCI2 (Optional)

If a ground fault is detected, the GFCI recep-

tacle Reset button pops out and the circuit opens to disconnect the faulty equipment. Check for damaged tools, cords, plugs, etc. connected to the receptacle. Press button to reset receptacle and resume operation.

.At least once a month, run engine at power/idle speed and press Test button to verify GFCI is working properly.

5Circuit Breaker CB5

6Circuit Breaker CB7

CB5 protects RC1 and CB7 protects RC2 from overload. If CB5 or CB7 opens, the receptacle does not work. Press button to reset breaker.

7 Circuit Breaker CB1

8 Circuit Breaker CB2

CB1 and CB2 protect all the 60 Hz receptacles from overload. If CB1 or CB2 opens, the 240 volt receptacle and one of the 120 volt receptacles does not work. 120 volts may still be present at the 240 volt receptacle. Press button to reset breaker.

9 Total Auxiliary Power Output

Combined output of receptacles limited to the 5 kVA/kW output of the generator:

EXAMPLE: If 10 A is drawn from a 120 V duplex receptacle, only 16 A is available at the 240 V receptacle:

(120 V x 10 A) + (240 V x 16 A) = 5.0 kVA/kW

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TM-428 Page 11

SECTION 5 ± THEORY OF OPERATION

1 Engine

Supplies force to turn revolving fields.

2 Revolving Fields (Rotor)

Turn at 1860 rpm maximum for power/idle and 3000 rpm maximum for weld. The speed and excitation current of the field coils determine voltages in stator windings.

3 Stator Windings

Supply power to exciter, auxiliary power, and weld circuits.

4 Fuse F1

Protects exciter excitation winding from overload.

5 Integrated Rectifier SR2

Changes ac output of stator windings to dc to supply excitation current to the exciter revolving field.

6 Control Relay CR5

Energizes when voltage is present in exciter stator to disconnect field flashing circuit.

7Idle Module PC1 And Idle Lock

Switch S1

PC1 and S1 control engine speed. Without a signal from CT1, PC1 lowers engine speed to power/idle rpm.

8 Throttle Solenoid TS1

Increases engine speed to weld rpm when energized.

9 Current Transformer CT1

Senses output from either weld or 100 Hz auxiliary power windings, and signals PC1 to increase to or maintain weld rpm.

10 Control Relays CR2, CR3, CR4

CR2 energizes at weld rpm to supply power to throttle solenoid TS1.

CR3 energizes at power/idle rpm to bypass fine amperage control R1.

CR4 energizes at power/idle rpm to provide 50/60 Hz auxiliary power output.

11Voltage Regulator Board PC2

And Transformer T1

PC2 monitors 50/60 Hz auxiliary power voltage through T1, and maintains proper output by adjusting field current.

12Capacitor Board PC5, Remote 14 Receptacle RC1, Remote Control Board PC3

PC5 protects unit from high frequency. RC1 connects remote amperage and contactor control to unit through control board PC3.

	13♦
	Remote Control
	Switch S4
	Remote 14	Panel
12♦	12♦
Capacitor Board	Remote
PC5 And Remote 14	Control Board
Receptacle RC1	PC3
		11
		Voltage
		Regulator
		Board PC2
18
	Fine	CR3
	Amperage
	Control R1
		3
1	2	Voltage		60 Hz Auxiliary
		Regulator		Power
Engine	Revolving	Stator Windings
	Fields (Rotor)
			100 Hz
		Exciter			Weld
			Auxiliary
	5		Power
8
		4
	Integrated
Throttle		Fuse
Solenoid	Rectifier SR2
		F1
TS1
	6♦		9
	Control			Current
	Relay
				Transformer
	CR5			CT1
	7	7	16
	Idle Module	Idle Lock		Circuit
	PC1	Switch S1		Breaker
				CB3
	10		17
	Control Relays			100 Hz
	CR2, CR3, CR4		Auxiliary Power
			Receptacle RC4

TM-428 Page 12

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11

CR4

Transformer

T1

14		15
	Circuit		50/60 Hz
	Breakers		Auxiliary Power
	CB1, CB2,		Receptacles
	CB5, CB7		RC1, RC2, RC3

19

Ampere

Ranges

Switch S5

	20				23		25
	Reactor									Electrode And
	AC-Z									Work AC Weld
										Output Terminals
21						HF Filter
	Main
						Board
	Rectifier					PC4
	SR1
22							24
										Positive (+) And
	Stabilizer									Negative (±) DC
	DC-Z									Weld Output
										Terminals

13 Remote Control Switch S4

Selects Panel or remote amperage control.

14Circuit Breakers CB1, CB2, CB5, And CB7

Protect 50/60 Hz auxiliary power receptacles RC1, RC2, and RC3 from overload.

1550/60 Hz Auxiliary Power Receptacles RC1, RC2, And RC3

Provide connection points and power for auxiliary equipment.

16 Circuit Breaker CB3

Protects 100 Hz auxiliary power receptacle RC4 from overload.

17100 Hz Auxiliary Power Receptacle RC4

Provides connection point and power for auxiliary equipment while welding.

18 Fine Amperage Control R1

Adjusts amperage within range selected by Ampere Ranges switch

S5.

19 Ampere Ranges Switch S5

Selects coarse range of weld output from weld stator.

20 Reactor AC-Z

Tapped reactor limits weld output and provides coarse ranges.

21 Main Rectifier SR1

Changes ac output from weld windings to dc.

22 Stabilizer DC-Z

Smooths out current to dc weld output terminals.

23HF Filter Board PC4 Protects unit from high frequency.

24Positive (+) And Negative (±)

DC Weld Output Terminals

Provide dc weld output.

25Electrode And Work AC Weld Output Terminals

Provide ac weld output.

AC Or DC Control Circuits

Weld Current Circuit

Mechanical Coupling

Magnetic Coupling

♦Optional

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TM-428 Page 13

NOTES

TM-428 Page 14

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SECTION 6 ± TROUBLESHOOTING

6-1. Troubleshooting Tables

A. Welding

.

See Sections 6-2 and 6-3 for test points and values and Section 10 for parts location.

Trouble	Remedy
No weld output.	Check fuse F1, and replace if necessary (see Section 8-6).
	Check integrated rectifier SR2, and replace if necessary.
	Check diode D4, and replace if necessary.
	Clean slip rings, and install new brushes if necessary (see Section 6-15).
	Disconnect leads 21, 23, and 33 from brushes, and check continuity across slip rings. Replace rotor
	if necessary.
	Check resistance and connections of resistors R2 and R4; R2 and R4 are each 12 ohms ±10%. Re-
	place resistor(s) if necessary. Adjust R2 and R4 according to Section 6-16.
	Check resistance and connections of Fine Amperage Control R1; R1 is 0 to 30 ohms ±10%. Replace
	R1 if necessary (see Section 3-1).
	Disconnect leads 22 and 29 from SCR/integrated rectifier SR2, and check for continuity between leads
	22 and 29. Replace exciter stator if necessary.
	For units with optional remote control, check capacitor C5 for a short or open, and check for proper con-
	nections. Replace C5 if necessary.
	Check voltage regulator board PC2 and connections, and replace if necessary (see Section 6-9).
No or erratic weld output.	Clean and tighten weld connections both inside and outside unit.
	Check engine speed, and adjust if necessary (see Section 8-5).
	Check to make sure Ampere Ranges switch S5 is not between positions. Check continuity of S5, and
	replace if necessary.
	Check reactor AC-Z for signs of winding failure. Check continuity across windings, and check for proper
	connections. Replace AC-Z if necessary.
	Check resistance and connections of Fine Amperage control R1; R1 is 0 to 30 ohms ± 10%. Replace
	R1 if necessary.
	Disconnect leads 21, 23, and 33 from brushes, and check continuity across slip rings. Replace rotor
	if necessary.
No or erratic DC weld output only.	Check modular main rectifier SR1, and replace if necessary.
	Check stabilizer DC-Z for signs of winding failure. Check continuity across windings, and check for
	proper connections. Replace DC-Z if necessary.
Low or high weld output.	Check engine speed, and adjust if necessary (see Section 8-5).
	Adjust resistor R4 slider until 128 to 132 volts ac is obtained at 100 Hz receptacle RC4 (see Section
	6-16).
	Adjust resistor R2 slider until proper open-circuit-voltage is obtained at weld output terminals (see Sec-
	tion 6-16).
	Check resistance and connections of resistor R3 on suppressor R3, VR1 module; R3 is 1000 ohms ±
	10%. Replace R3, VR1 module if necessary.
	Check reactor AC-Z for signs of winding failure. Check continuity across windings, and check for proper
	connections. Replace AC-Z if necessary.

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TM-428 Page 15

B. 50 Or 60 Hz Auxiliary Power

Trouble	Remedy
No auxiliary power output at recep-	Run engine at power/idle speed.
tacles RC1, RC2, or RC3.
	Reset circuit breakers CB1 and CB2. Effective with Serial No. KE629034, also reset circuit breakers
	CB5 and CB7 (see Section 4-3).
	Check receptacles RC1, RC2, RC3 for continuity and proper connections. Replace receptacle(s) if nec-
	essary.
	Check connections to terminal strip 1T.
	Clean slip rings, and install new brushes if necessary (see Section 6-15).
	Check coil voltage and connections of control relay CR4. Check continuity of coil and condition of con-
	tacts. Replace CR4 if necessary.
	Check diode D4, and replace if necessary.
	Check idle board/module PC1 and connections (see Section 6-5).
	Check control transformer T1 for signs of winding failure. Check continuity across windings, and check
	for proper connections. Check primary and secondary voltages. Replace T1 if necessary.
	Disconnect leads 21, 23, and 33 from brushes, and check continuity across slip rings. Replace rotor
	if necessary.
	Disconnect leads 48 and 49 from voltage regulator board PC2, and check continuity between leads 48
	and 49. Disconnect leads 50, 51, 52, and 53 from stator. Check continuity between leads 50 and 51,
	and 52 and 53. Replace stator if necessary.
Low auxiliary power output.	Check connections to terminal strip 1T.
	Clean slip rings, and install new brushes if necessary (see Section 6-15).
	Check integrated rectifier SR2, and replace if necessary.
	Check coil voltage and connections of control relay CR3. Check continuity of coil and condition of con-
	tacts. Replace CR3 if necessary.
	Check voltage regulator board PC2 and connections, and replace if necessary.
High auxiliary power output.	Check engine speed, and adjust if necessary.
	Check voltage regulator board PC2 and connections, and replace if necessary (see Section 6-9).

C. 100 Hz Auxiliary Power

Trouble	Remedy
No auxiliary power output at receptacle	Run engine at weld speed.
RC4.
	Reset circuit breaker CB3 (see Section 4-1).
	Check receptacle RC4 for continuity and proper connections. Replace receptacle if necessary.
	Disconnect leads 90, 91, 92, and 93 from stator. Check continuity between leads 90 and 91, and 92 and
	93. Replace stator if necessary.
	Check diode D4, and replace if necessary.

TM-428 Page 16

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D. Engine

Trouble	Remedy
Engine will not start.	Check fuel level (see Section 2-4).
	Check battery and engine charging system according to engine manual.
	Check continuity of Engine Control switch S2, and replace if necessary.
	See engine manual.
Engine starts but stops as soon as En-	Check oil level (see Section 2-4). Check low oil pressure shutdown switch S3 (see engine parts manual
gine Control switch S2 returns to Run	for location). S3 should close when engine is running.
position.
	Check and refill crankcase with proper viscosity oil for operating temperature, if necessary (see engine
	manual).
	Check continuity of Engine Control switch S2, and replace if necessary.
Engine stopped during normal opera-	Check oil level (see Section 2-4). Check low oil pressure shutdown switch S3 (see engine parts manual
tion.	for location). S3 should close when engine is running.
	Check continuity of Engine Control switch S2, and replace if necessary.
Battery discharges between uses.	Make sure Engine Control switch S2 is placed in the Off position when engine is not in use (see Section
	3-1).
	Prior to Serial No. KA780044, check fuse F2 and replace if necessary.
	Clean battery, terminals and posts with baking soda solution; rinse with clear water.
	Periodically recharge battery (approximately every 3 months).
	Check voltage regulator according to engine manual.
	Replace battery.
Engine idles, but does not come up to	Wait 10 seconds for throttle solenoid circuit breaker CB4 to reset (see Section 8-6).
weld speed.
	Place Idle Lock switch S1 in Unlock position (see Section 3-1).
	Check continuity and connections of current transformer CT1, and replace if necessary.
	Check continuity of Engine Control switch S2, and replace if necessary.
	Check coil voltage and connections of control relay CR2. Check continuity of coil and condition of con-
	tacts. Replace CR2 if necessary.
	Check diode D6 in throttle solenoid TS1 circuit, and replace if necessary.
	Check resistance at throttle solenoid TS1 terminals. With plunger out, resistance is less than 1 ohm.
	With plunger bottomed, resistance is 17 ohms ±10%.
	Check throttle linkage for smooth, non-binding operation.
	Check idle board/module PC1 and connections, and replace if necessary (see Section 6-5).
Engine does not return to idle speed.	Remove weld load.
	Check continuity of Engine Control switch S2, and replace if necessary.
	Check throttle linkage for smooth, non-binding operation.
Unstable or sluggish engine speeds.	Readjust throttle linkage if necessary.
	Tune-up engine according to engine manual.

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TM-428 Page 17