Lincoln Electric Comprehensive Troubleshooting for Lincoln DC 400 Welding Machines

Page 30

E-3

TROUBLESHOOTING

E-3

 

 

 

 

Observe all Safety Guidelines detailed throughout this manual

 

 

 

 

PROBLEMS

(SYMPTOMS)

POSSIBLE

CAUSE

RECOMMENDED

COURSE OF ACTION

Machine has high output or pulsing

1.

Terminals 75, 76, or 77 grounded

output and no control.

 

to negative output.

 

 

 

 

Machine has low output and no

1.

OUTPUT CONTROL “LOCAL-

control.

 

REMOTE” switch (S2) in wrong

 

 

position. Check position of

 

 

switch.

 

2.

OUTPUT CONTROL switch

 

 

faulty. Check switch & replace if

 

 

faulty.

 

3.

Open in feedback circuitry.

 

4.

Faulty Control PC Board.

 

5.

OUTPUT control potentiometer

 

 

circuit open (lead 75).

 

 

 

 

Machine does not have maximum

1.

One input fuse blows. Check and

output.

 

replace if blown after checking for

 

 

reason for blown fuse.

 

2.

One phase of main transformer

 

 

open.

 

3.

Faulty Control PC Board.

 

4.

OUTPUT control potentiometer.

 

5.

OUTPUT control potentiometer

 

 

leads 210, 211 or 75 open.

 

 

 

Machine will not shut off.

1.

Input contactor contacts frozen.

 

2.

Defective POWER “1/0” switch,

 

 

(S1).

 

 

 

Variable or sluggish welding arc.

1.

Poor work or electrode connec-

 

 

tion. Place switch in “LOCAL”.

 

2.

Welding leads too small.

 

3.

Welding current or voltage too

 

 

low.

 

4.

Defective main SCR bridge.

 

5.

Microswitch S4C or S4D actuator

 

 

defective.

 

 

 

OUTPUT control not functioning on

1.

OUTPUT CONTROL switch in

the machine.

 

wrong position.

 

2.

Faulty OUTPUT control switch.

 

3.

Faulty OUTPUT control poten-

 

 

tiometer.

 

4.

Leads or connections open in

 

 

control circuit.

 

5.

Faulty Control PC Board.

 

 

 

 

If all recommended possible areas of misadjustment have been checked and the problem persists, Contact your local Authorized Field Service Facility.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

DC-400

Image 30
Contents RED-D-ARC DC-400 10699 11038 11085 11128 11347Safety California Proposition 65 WarningsElectric Shock can kill Welding Sparks can cause fire or explosion IiiPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcPlease Examine Carton and Equipment For Damage Immediately On-Line Product RegistrationTable of Contents Vii Section DSection E Output Maximum Open Circuit Voltage Auxiliary Power InstallationTechnical Specifications DC-400 Height Width Depth Weight400A 100% 500A 50% Machine LoadCable Duty Lengths CycleRemote Control Adapter Cable K864 Multiprocess Switch K804-1 Design Multiprocess Switch Connection and Operation PurposeConnection of DC-400 to LN-22 or LN-25 OperationCase Features Auxiliary Power ConnectionsRemote Control Connections Output ConnectionsMachine & Circuit Protection Thermal Protection Light Multiprocess Switch STICK, TIG or AIR/CARBON ARCOperation Electric Shock can killVoltmeter Switch Rating Plate ARC Control SwitchOutput Terminals Switch ARC Force Control DialIP21 Degree of protection provided by the enclosure4OPERATIONB-4 Earth Ground ConnectionSignifying the Earth Ground Connection DC-400 Recommended Processes & Equipment Duty Cycle and Time Period Power Source OperationVoltmeter Switch Duty Cycle Amps VoltsFront View of 14-PIN Connector Receptacle ARC Force Control Dial Effective only in CC modeARC Control Switch Effective only in CV FCAW/GMAW mode PIN Lead no FunctionTerminal Strip Connections Machine and Circuit ProtectionAccessories Factory Installed OptionsField Installed Options HI-FREQUENCY KIT K799 Codes 8634 and Above only Undercarriages K817, K817R, K8411MAINTENANCED-1 Routine MaintenanceTroubleshooting HOW to USE Troubleshooting GuideContact your local Authorized Field Service Facility Output Control Local Service Facility Your local Authorized FieldFault Protection Operation Procedure for Replacing PC BoardsConnecting the Remote Control to the Machine Power I/0 Switch CheckPower Rectifier Bridge Assembly Checking Procedure Remote Control CheckPower Diode Test Power Silicon Controlled Rectifier TestDiagrams Wiring Diagram for CodeWiring Diagram for Code 10699 and Above Pasted inside Number11085, 11128 Power Rectifier Bridge Diagram Dimension Print Type M12244-7 DC-400 32.00 15.39 30.92 30.02 +.11DC-400 Precaucion Warnung
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DC-400 specifications

The Lincoln Electric DC-400 is a versatile and robust DC arc welding power source designed to meet the demands of various industrial applications. Known for its reliability and performance, the DC-400 is ideal for both professional welders and fabrication shops requiring robust equipment that can handle challenging welding tasks.

One of the main features of the DC-400 is its ability to provide a smooth, stable arc, which is essential for achieving high-quality welds. This welding machine is capable of delivering a wide amperage range, typically from 20 to 400 amperes, making it suitable for various welding processes, including MIG, TIG, and Stick welding. The unit's high output capabilities allow it to effectively weld a variety of materials, such as steel, stainless steel, and various alloys.

In terms of technology, the DC-400 integrates advanced power conversion technology that enhances energy efficiency while minimizing heat loss during operation. This not only contributes to lower operating costs but also ensures a longer service life for the machine. The DC-400 features a durable, rugged design, with a robust steel frame that can withstand the rigors of heavy industrial use while providing an IP23 rating for protection against moisture and dust.

Another notable characteristic of the DC-400 is its ease of use. The intuitive controls allow for quick adjustments to settings, enabling welders to easily adapt to different job requirements. The arc characteristics of the DC-400 can be fine-tuned to optimize performance for different welding applications, ensuring consistent results every time.

Moreover, the DC-400 is equipped with built-in safety features such as thermal overload protection, which prevents damage to the machine in case of prolonged operation under heavy loads. This feature enhances the safety of the operator and extends the life of the welding machine.

Overall, the Lincoln Electric DC-400 stands out as a reliable and efficient welding power source. Its combination of high-performance capabilities, advanced technology, and next-level usability makes it a popular choice in the industry. Whether for heavy fabrication, maintenance, or repair work, the DC-400 continues to prove itself as an indispensable tool for professional welders seeking quality and durability in their equipment.