Lincoln Electric SAM650, SAM400 manual Diode Test Procedure, SCR Bridge PC Board Test Procedure

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E-6

TROUBLESHOOTING

E-6

 

 

 

DIODE TEST PROCEDURE

Standard Polarity

 

 

 

 

 

 

 

Reverse Polarity

 

 

 

 

 

 

 

 

 

Anode

 

 

 

 

 

 

Cathode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cathode

 

 

 

 

 

 

Anode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conventional

Symbol

 

 

 

 

 

 

 

Symbol

Conventional

Current Flow

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current Flow

Figure E.1

1.Isolate the diode in question from the remainder of the circuit and determine its polarity from the wiring diagram and Figure E.1.

2.Establish the polarity of the ohmmeter leads.

3.Connect the ohmmeter across the diode in question as illustrated in Figures E.2 and E.3 below. Note polarity of ohmmeter in reference to diode.

A SHORTED DIODE will indicate equally low resistance in both directions.

AN OPEN DIODE will have infinite or high resistance in both directions.

A GOOD DIODE will have a reverse resistance much higher than forward resistance.

+

 

 

 

OHMMETER

 

-

 

 

 

 

 

 

 

 

 

 

 

 

 

i

 

Anode

 

Cathode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Forward Resistance Low

 

 

 

 

Figure E.2

 

 

 

 

 

 

 

 

 

-

 

 

 

OHMMETER

 

 

+

 

 

 

 

 

 

 

 

 

 

 

 

 

 

i

 

Anode

 

Cathode

 

 

 

Reverse Resistance Low

Figure E.3

SCR BRIDGE PC BOARD TEST PROCEDURE

CAUTION

THE SCR BRIDGE SHOULD BE CHECKED BEFORE INSTALLING NEW CONTROL BOARD. COMPONENTS ON THE NEW CONTROL BOARD COULD BE DAMAGED BY A DEFECTIVE SCR BRIDGE.

1.Visually inspect the board for obvious failures.

2.Remove all leads from the terminal strip of the SCR Bridge PC Board.

3.Check C5 and C6 for a short. Read the resistance between terminals 210 and 214 for C5, and between ter- minals 212 and 213 for C6.

4.Check SCR1 and SCR2. For SCR1, attach the (-) ohm- meter lead to the "Brn" Terminal. Place the (+) lead first on Terminal 210 and then on Terminal 214 and record the resistance of each. To check SCR2, keep the (-) lead on the Brn terminal and with the (+) lead on Terminal 212 and then on Terminal 214 record the resistances read. Reverse the leads and repeat the above tests. The sec- ond resistance values should all be higher than those recorded first. The ohmmeter should be set in its highest range or in "Auto Range".

5.Check D1 and D2. Place the (-) lead on Terminal 75, and place the (+) lead on Terminal 214 for D1. Keeping the (- ) lead on Terminal 75, attach the (+) lead to Terminal 212 to test D2. This tests the diodes in the "forward" direction. Reverse the leads and repeat the previous test. This tests the diodes in the "reverse" direction. The resistance val- ues in the reverse direction should all be higher than those in the forward direction.

6.Test D3 and R28. Connect the (+) lead to the Brn Terminal and the (-) lead to the 75 Terminal and record the resistance. Reverse the meter leads to test the diode in the reverse direction. The resistance in the reverse direc- tion should be higher than it is in the forward direction.

a)If your ohmmeter has a "Diode Test Range"

( ), use that range for this test. Otherwise use "Auto Range" or the lowest range that pro- duces a meter reading.

b)If D3 is open (or you are using too high a range on the ohmmeter) you will read only the value of R28 (about 1200 ohms) in both directions. If D3 is shorted, you will read zero ohms or a very low resistance in both directions.

7.If the board fails any of the tests, replace it.

SAM400 & 650

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Contents IM568 SAM400 SafetyElectric Shock can kill Welding Sparks can cause fire or explosion Sûreté Pour Soudage a L’Arc Précautions DE SûretéThank You Table of Contents HEIGHT1 Width Depth Weight InstallationTechnical Specifications SAM400 Height Width Depth Weight Technical Specifications SAM650Product Description Installation PrecautionsSpark Arrester Machine GroundingWelder Location PRE-OPERATION ServiceOutput Cables Additional Safety Precautions Operating PrecautionsOperation Pipe ThawingOutput Studs Welder Controls FUNCTION/OPERATIONPortable Field Control Connection Mounting on LN-7Electrode Polarity Switch Toggle SwitchContactor Current and Voltage ControlsTo Set The Controls -- Submerged Arc Variable Voltage WeldingTo Set The Controls -- Stick Welding SAM400 Controls Operation SAM650 Controls Operation Duty Cycle Auxiliary PowerStarting Instructions BREAK-IN PeriodAccessories Routine Maintenance MaintenancePeriodic Maintenance Bearing MaintenanceContactor Maintenance Commutator and Brush MaintenanceCooling System APR97HOW to USE Troubleshooting Guide TroubleshootingFunction Problems Symptoms Course of ActionLoss of Output in Both Modes of Operation Control Boards. Note a Pg. E-2 Recommended SCR Bridge PC Board Test Procedure Diode Test ProcedureControl PC Board Calibration Ground Tests LOW Voltage Option SAM400 Machine Wiring DiagramSAM650 Machine Wiring Diagram Wiring DiagramsMaintenance Instructions Daily Checks SAM400 Engine Wiring DiagramTerminal SAM650 Engine Wiring DiagramDimension Print Dimension Print SAM400 and SAM650 Perkins Engine Welders$700.00 Basic CoursePrecaucion Aviso DE Warranty Period Statement of Warranty To Obtain Warranty CoverageWarranty Repair Warranty Costs

SAM650, SAM400 specifications

Lincoln Electric has long been synonymous with welding excellence, and its SAM series of advanced welding machines, including the SAM400 and SAM650, epitomizes this commitment to quality and innovation. These models are designed to meet the demands of diverse industrial applications while ensuring ease of use, efficiency, and precision.

The SAM400 is a robust multiprocess welding system that supports MIG, TIG, Stick, and Flux-Cored welding techniques. It features a powerful 400 Amp output, suitable for heavy-duty applications and capable of handling materials such as steel, stainless steel, and aluminum. The machine incorporates advanced inverter technology, resulting in a compact design that significantly reduces the weight while enhancing portability. Furthermore, the SAM400 includes intuitive digital controls, allowing operators to easily adjust settings for optimal performance. Its PAS (Power Adapter System) compatibility enables users to seamlessly integrate different power sources, greatly enhancing its versatility.

On the other hand, the SAM650 takes it a step further, boasting a maximum output of 650 Amps. This model is particularly favored in industries requiring high deposition rates, such as shipbuilding and heavy fabrication. Like the SAM400, the SAM650 features multiprocess capabilities but adds enhanced control mechanisms, such as advanced waveform technology, which allows for better arc stability and reduced spatter. This ensures cleaner welds and, ultimately, a superior finish. Additionally, the SAM650 is equipped with Lincoln Electric's proprietary welding technology, including the Arc Control and Hot Start features that enhance user experience by providing smoother starts and consistent performance, even in challenging conditions.

Both machines come with integrated wire feeders that allow for easy adjustments and quick material changes, offering increased productivity on the job site. Their rugged design and durable construction ensure long-lasting performance, even in the harshest environments.

In conclusion, the Lincoln Electric SAM400 and SAM650 welding systems are trailblazers in the field of welding technology. With their powerful output, advanced features, and user-friendly interfaces, these machines cater to the needs of professionals looking for reliability and efficiency in their welding applications. Whether for small shops or large-scale industrial operations, the SAM400 and SAM650 deliver the performance and versatility that fabricators and welders depend on.
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