OM-220 812B March 2005 Processes Stick (SMAW) Welding TIG (GTAW) Welding Description Arc Welding Power Source CST 250 VRD International Visit our website at www.MillerWelds.
From Miller to You Thank you and congratulations on choosing Miller. Now you can get the job done and get it done right. We know you don’t have time to do it any other way. That’s why when Niels Miller first started building arc welders in 1929, he made sure his products offered long-lasting value and superior quality. Like you, his customers couldn’t afford anything less. Miller products had to be more than the best they could be. They had to be the best you could buy.
TABLE OF CONTENTS SECTION 1 − SAFETY PRECAUTIONS - READ BEFORE USING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1. Symbol Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2. Arc Welding Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3.
SECTION 1 − SAFETY PRECAUTIONS - READ BEFORE USING som _8/03 1-1. Symbol Usage Means Warning! Watch Out! There are possible hazards with this procedure! The possible hazards are shown in the adjoining symbols. 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.
ARC RAYS can burn eyes and skin. Arc rays from the welding process produce intense visible and invisible (ultraviolet and infrared) rays that can burn eyes and skin. Sparks fly off from the weld. Wear a welding helmet fitted with a proper shade of filter to protect your face and eyes when welding or watching (see ANSI Z49.1 and Z87.1 listed in Safety Standards). Wear approved safety glasses with side shields under your helmet.
1-3. Additional Symbols For Installation, Operation, And Maintenance FIRE OR EXPLOSION hazard. MOVING PARTS can cause injury. Do not install or place unit on, over, or near combustible surfaces. Do not install unit near flammables. Do not overload building wiring − be sure power supply system is properly sized, rated, and protected to handle this unit. Keep away from moving parts such as fans. Keep all doors, panels, covers, and guards closed and securely in place.
1-5. Principal Safety Standards Safety in Welding, Cutting, and Allied Processes, ANSI Standard Z49.1, from American Welding Society, 550 N.W. LeJeune Rd, Miami FL 33126 (phone: 305-443-9353, website: www.aws.org). Boulevard, Rexdale, Ontario, Canada M9W 1R3 (phone: 800−463−6727 or in Toronto 416−747−4044, website: www.csa−international.org). Recommended Safe Practices for the Preparation for Welding and Cutting of Containers and Piping, American Welding Society Standard AWS F4.
SECTION 2 − CONSIGNES DE SÉCURITÉ − À LIRE AVANT UTILISATION som_fre 8/03 2-1. Signification des symboles Signifie « Mise en garde. Faire preuve de vigilance. » Cette procédure présente des risques identifiés par les symboles adjacents aux directives. Identifie un message de sécurité particulier. Signifie « NOTA » ; n’est pas relatif à la sécurité. Ce groupe de symboles signifie « Mise en garde. Faire preuve de vigilance.
LES RAYONS DE L’ARC peuvent causer des brûlures oculaires et cutanées. Le rayonnement de l’arc génère des rayons visibles et invisibles intenses (ultraviolets et infrarouges) susceptibles de causer des brûlures oculaires et cutanées. Des étincelles sont projetées pendant le soudage. Porter un masque de soudage muni d’un filtre de la nuance adéquate pour se protéger le visage et les yeux pendant le soudage ou pour regarder (voir les normes de sécurité ANSI Z49.1 et Z87.1).
2-3. Autres symboles relatifs à l’installation, au fonctionnement et à l’entretien de l’appareil. Risque D’INCENDIE OU D’EXPLOSION LES ORGANES MOBILES peuvent causer des blessures. Ne pas placer l’appareil sur une surface inflammable, ni au−dessus ou à proximité d’elle. Se tenir à l’écart des organes mobiles comme les ventilateurs. Maintenir fermés et bien fixés les portes, panneaux, recouvrements et dispositifs de protection. Ne pas installer l’appareil à proximité de produits inflammables.
2-4. Principales normes de sécurité Safety in Welding, Cutting, and Allied Processes, norme ANSI Z49.1, de l’American Welding Society, 550 N.W. LeJeune Rd, Miami FL 33126 (téléphone : (305) 443−9353, site Web : www.aws.org). Rexdale, Rexdale (Ontario) Canada M9W 1R3 (téléphone : (800) 463−6727 ou à Toronto : (416) 747−4044, site Web : www.csa−international.org). Recommended Safe Practices for the Preparation for Welding and Cutting of Containers and Piping, norme American Welding Society AWS F4.
SECTION 3 − INSTALLATION 3-1. Specifications Welding Mode Input Power 3-Phase Stick (SMAW) 1-Phase Rated Output 250 A @ 30 VDC, 50 % Duty Cycle 200 A @ 28 VDC, 100 % Duty Cycle 200 A @ 28 VDC, 50 % Duty Cycle 150 A @ 26 VDC, 100 % Duty Cycle Welding Amperage Range 5-250 A 5-200 A Maximum Amperes Input At Rated Load Open-Circuit Output, 50/60 Hz Voltage 220 400 440 KVA KW 32.1 18.2 16.4 12.3 8.7 24.2 14.4 12.6 9.9 6.
3-3. Stick (SMAW) Volt-Ampere Curves Volt-ampere curves show minimum and maximum voltage and amperage output capabilities of welding power source. Curves of other settings fall between curves shown.
3-4. TIG (GTAW) Volt-Ampere Curve Volt-ampere curves show minimum and maximum voltage and amperage output capabilities of welding power source. Curves of other settings fall between curves shown.
3-5. Selecting A Location 1 Line Disconnect Device Locate unit near correct input power supply. Dimensions And Weight 40 lb (18.2 kg) - with power cord Special installation may be required where gasoline or volatile liquids are present − see NEC Article 511 or CEC Section 20.
3-6.
3-7. TIG Lift-Arct DCEN (Direct Current Electrode Negative) Connections 1 5 4 Positive (+) Weld Output Terminal Connect work lead to positive weld output terminal. 2 Negative (−) Weld Output Terminal 6 Connect TIG torch to negative weld output terminal. 3 3 4 Gas Cylinder Cylinder Valve Open valve slightly so gas flow blows dirt from valve. Close valve. 5 6 Regulator/Flowmeter Flow Adjust Typical flow rate is 15 cubic feet per hour (7.1 liters per minute). Connect torch gas regulator/flowmeter.
3-8. Stick DCEP (Direct Current Electrode Positive) Connections 1 Negative (−) Weld Output Terminal Connect work lead to negative weld output terminal. 2 Positive (+) Weld Output Terminal Connect electrode holder positive weld output terminal. to 2 1 Ref. 802 888 / Ref. 803 080 3-9. Electrical Service Guide CAUTION: INCORRECT INPUT POWER can damage this welding power source. This welding power source requires a CONTINUOUS supply of 50/60 Hz power at +10% of rated input voltage.
3-10. Selecting 220 Volts AC Single/Three Phase Input Voltage Turn Off welding power source, and disconnect input power before proceeding. Check input voltage available at site. 1 Voltage Selection View Window The input voltage that the power source is linked for appears in the Voltage Selection View Window. Check voltage selected in unit. Changing selection is only necessary if selected value does not match available input voltage.
3-11. Selecting 400 - 440 Volts AC Three Phase Input Voltage Turn Off welding power source, and disconnect input power before proceeding. Check input voltage available at site. 1 Voltage Selection View Window The input voltage that the power source is linked for appears in the Voltage Selection View Window. Check voltage selected in unit. Changing selection is only necessary if selected value does not match available input voltage.
3-12. Connecting Input Power Disconnect and lockout/tagout input power before connecting input conductors from unit. Have only qualified persons make this installation. See rating label on unit and check input voltage available at site. 3 1 1 2 Input And Grounding Conductors Line Disconnect Device See Section 3-9. For three-phase operation: Always connect green or green/yellow wire to supply grounding terminal, never to a line terminal.
SECTION 4 − OPERATION 4-1. Controls 2 5 3 4 1 CST 250 VRD 6 NOTE: Green on nameplate indicates a TIG function, Gray indicates a Stick function. 1 Power Switch Use switch to turn unit and indicator light On/Off. 2 Output Indicator Light When unit is first energized this indicator light flashes several times and then illuminates continuously. When unit is shut down, the indicator light flashes several times and the cooling fan will run briefly, then both will turn off completely.
4-2. Process Select Control 1 Process Select Control Rotate knob to select desired process. 1 Lift-Arc TIG - Normal open-circuit voltage is not present between the electrode and workpiece. A solid-state contactor does not energize until after the electrode touches the workpiece, preventing overheating, sticking, or contaminating the electrode (see Section 4-4). Make connections according to Section 3-7. Stick E XX18 Soft - This setting provides a lower dig/arc force setting for smooth weld perfromance.
4-3. Stick Start Procedure − Scratch Start Technique With Stick selected, start arc as follows: 1 2 3 Electrode Workpiece Arc Drag electrode across workpiece like striking a match; lift electrode slightly after touching work. If arc goes out electrode was lifted to high. If electrode sticks to workpiece, use a quick twist to free it. 1 2 3 Normal open-circuit voltage is not present before electrode touches workpiece; only a low sensing voltage is present between electrode and workpiece.
4-5. Amp Adjust Control 1 1 AMP ADJUST (Amperage Control) Rotate knob clockwise to increase amperage (5-250 amps). 4-6. Remote 14 Receptacle Information This unit automatically senses when a remote control is connected to the remote 14 receptacle. After connecting a remote control, the unit will automatically adjust output control to a primary/secondary configuration. In this configuration, the AMP ADJUST control on the unit becomes the primary and sets the maximum amperage output of the unit.
SECTION 5 − MAINTENANCE AND TROUBLESHOOTING 5-1. Routine Maintenance Disconnect power before maintaining. Maintain more often during severe conditions. 3 Months Replace unreadable labels. Clean and tighten weld terminals. Replace Damaged Gas Hose 3 Months Repair Or Replace Cracked Cables And Cords 6 Months Do not remove case when blowing out inside of unit (see Section 5-2) . Blow out inside. During heavy service clean monthly. 5-2.
5-3. Troubleshooting 1 2 Output LED (Blue) High Temperature LED (Yellow) 1 2 803 080 Trouble No weld output; unit completely inoperative. Possible Causes Remedy Line disconnect switch open. Place line disconnect switch in On position (see Section 3-12). Blown line fuse(s). Check and replace line fuse(s), if necessary, or reset circuit breaker (see Section 3-12). Improper input power connections. Check for proper input power connections (see Section 3-12). Line voltage too high or too low.
Trouble Erratic or improper weld output. Wandering arc Possible Causes Remedy Weld cable too small or defective. Use proper size and type of weld cable (see Section 3-6). Dirty or loose connections. Clean and tighten all weld connections (see Section 3-6). Improper size tungsten. Use proper size tungsten (see Section 7). Worn or defective tungsten. Use properly prepared tungsten (see Section 7). Shielding gas flow too high. Reduce shielding gas flow rate (see Section 3-7).
SECTION 6 − ELECTRICAL DIAGRAMS Figure 6-1.
SECTION 7 − SELECTING AND PREPARING TUNGSTEN ELECTRODE gtaw 7/97 NOTE For additional information, see your distributor for a handbook on the Gas Tungsten Arc Welding (GTAW) process.Wear clean gloves to prevent contamination of tungsten electrode. 7-1.
7-3. Preparing Tungsten For AC Or DC Electrode Negative (DCEN) Welding 1 1 2 2 Tungsten Electrode Tapered End Grind end of tungsten on fine grit, hard abrasive wheel before welding. Do not use wheel for other jobs or tungsten can become contaminated causing lower weld quality. 2-1/2 Times Electrode Diameter 1 2 3 1 2 Stable Arc Flat Diameter of this flat determines amperage capacity. 3 Grinding Wheel Grinding wheel should be dedicated to grinding tungsten only.
Notes OM-220 812 Page 29
SECTION 8 − PARTS LIST Hardware is common and 12 not available unless listed. 8 27 21 20 13 6 26 15 25 15 14 9 7 14 24 23 19 11 16 3 22 17 2 4 10 19 28 18 1 5 803 157-B Figure 8-1.
Item No. Dia. Mkgs. Part No. Description Quantity Figure 8-1. Main Assembly . . . 1 . . . . . . . . . . 205758 . . . 2 . . . . . . . . . . 205780 . . . 3 . . . . . . . . . . 212809 . . . 4 . . . . . . . . . . 206090 . . . 5 . . . . . . . . . . 206039 . . . 6 . . . . . . . . . . 206093 . . . 7 . . . . . . . . . . 206038 . . . 8 . . . . . . . . . . 206164 . . . 9 . . . . . . . . . . 206165 . . . 10 . . . . . . . . . . 206166 . . . 11 . . . . . . . . . . 207437 . . . 12 . . . . . . . . . . 206108 . . .
Hardware is common and 8 not available unless listed. 19 20 1 4 7 2 18 14 23 9 13 12 4 22 6 15 5 3 7 17 21 16 11 10 803 158 Figure 8-2. Panel, Front w/Components Item No. Diagram marking Part No. Description Quantity Figure 8-2. Panel, Front w/Components ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 .............. .............. .............. . . . . S1 . . . . . . ..........
Hardware is common and 2 not available unless listed. 6 7 5 7 1 3 4 803 161-B Figure 8-3. Panel, Rear w/Components Item No. Dia. Mkgs. Part No. Description Quantity Figure 8-3. Panel, Rear w/Components ... ... ... ... ... ... ... 1 2 3 4 5 6 7 . . . . . . . . . . 194242 . . . . . . . . . . 206052 . . . . . . . . . . 206053 . . . . . . . . . . 210128 . . . . . . . . . . 145217 . . . . . . . . . . 207253 . . . . . . . . . . . 201155 .. .. .. .. .. .. .. PANEL,FRONT/REAR . . . . . . . . . . .
Hardware is common and 13 not available unless listed. 8 14 7 3 8 12 11 16 10 9 6 8 1 15 5 2 4 803 163-B Figure 8-4. Magnetics Subassembly Item No. Dia. Mkgs. Part No. Description Quantity Figure 8-4. Magnetics Subassembly ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 .......... . . . . T1 . . . . . FM . . . . . . Z1 . . . . . CR1 . . . . . . R3 . . . . . . C3 . . .......... .......... . . . . L3 . . .......... .......... ....
Hardware is common and 10 not available unless listed. 11 12 12 13 13 4 7 2 9 3 6 8 1 5 803 159-C Figure 8-5. Heat Sink Assembly, Output Diode Item No. Dia. Mkgs. Part No. Description Quantity Figure 8-5. Heat Sink Assembly, Output Diode ... ... ... ... ... ... ... ... ... ... ... ... ... 1 2 3 4 5 6 7 8 9 10 11 12 13 . . . . . . . . . . 205916 . . D1,D2 . 223422 . . . SR1 . . 201530 . . . HD1 . . 191941 . . R2,C6 . 196510 . . R1,C5 . 207384 . . . RT1 . . 199798 . . . . . . . . . . .
Hardware is common and not available unless listed. 3 1 6 7 8 4 2 5 803 160 Figure 8-6. Base Assembly Item No. Dia. Mkgs. Part No. Description Quantity Figure 8-6. Base Assembly ... ... ... ... ... ... ... ... 1 2 3 4 5 6 7 8 .......... .......... . . C7,C8 . .......... .......... .......... .......... .......... 206089 019663 186543 133528 195666 601862 602203 602238 .. .. .. .. .. .. .. .. BASE, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hardware is common and not available unless listed. 2 1 3 Ref. 803 162 Figure 8-7. Heat Sink Assembly, Input Item No. Dia. Mkgs. Part No. Description Quantity Figure 8-7. Heat Sink Assembly, Input . . . 1 . . . . . . . . . . 205915 . . HEAT SINK,IGBT/INPUT RECTIFIER MODULE . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . 2 . . . . . . . . . . 206091 . . BRACKET,HEATSINK REAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . 3 . . . TE1 . . 206328 .
Notes
Effective January 1, 2005 (Equipment with a serial number preface of “LF” or newer) This limited warranty supersedes all previous Miller warranties and is exclusive with no other guarantees or warranties expressed or implied. Warranty Questions? Call 1-800-4-A-MILLER for your local Miller distributor. Your distributor also gives you ... Service You always get the fast, reliable response you need. Most replacement parts can be in your hands in 24 hours.
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