OM-1315 January 1997 Eff. w/Serial Number KH303568 Processes Gas Metal Arc (MIG) Welding Flux Cored Arc (FCAW) Welding Description Arc Welding Power Source and Wire Feeder R Millermatic 250MP 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 The following terms are used interchangeably throughout this manual: MIG = GMAW 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 _nd_5/97 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.
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. D 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). D 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. D Do not install or place unit on, over, or near combustible surfaces. D Do not install unit near flammables. D Do not overload building wiring – be sure power supply system is properly sized, rated, and protected to handle this unit. D Keep away from moving parts such as fans. D Keep all doors, panels, covers, and guards closed and securely in place.
1-5. EMF Information Considerations About Welding And The Effects Of Low Frequency Electric And Magnetic Fields 1. Keep cables close together by twisting or taping them. Welding current, as it flows through welding cables, will cause electromagnetic fields. There has been and still is some concern about such fields.
SECTION 2 – INSTALLATION 2-1. Specifications Max. OpenCircuit Voltage Rated Output 250 A at 28 VDC, 40% Duty Cycle 200 A at 28 VDC, 60% Duty Cycle Amps Input at Rated Output, 50 or 60 Hz, Single-Phase 200 V 220 V 230 V 380 V 415 V 460 V 575 V KVA KW 50 2.3* 45 2.2* 44 2* 26 1.3* 24 1.2* 22 1* 18 0.8* 10 0.46* 7.7 0.13* 32 Wire Type and Diameter Solid Steel Stainless Steel Flux Cored .023 – .045 in (0.6 – 1.2 mm) .023 – .035 in (0.6 – 0.9 mm) .030 – .045 in (0.8 – 1.
2-3. Volt-Ampere Curves 1 Normal Volt-Ampere Curves The volt-ampere curves show the normal minimum and maximum voltage and amperage output capabilities of the welding power source. Curves of other settings fall between the curves shown. 1 2 Overload Volt-Ampere Curves When unit is used beyond capacity, circuitry senses the overload and shuts down unit output. Release trigger and lower weld voltage setting before trying to weld.
2-5. Installing Welding Gun 1 2 3 1 Drive Assembly Gun Securing Knob Gun End Loosen securing knob. Insert gun end through opening until it bottoms against drive assembly. Tighten knob. 2 4 4 Gun Trigger Plug Insert plug into receptacle, and tighten threaded collar. Close door. 3 Ref. ST-150 256-D 2-6. Setting Gun Polarity For Wire Type . Always read and follow wire manufacturer’s recommended polarity, and see label inside unit by wire drive assembly. Tools Needed: 3/4 in 2-7.
2-8. Installing Drive Roll And Wire Inlet Guide 1 2 5 3 2 Securing Screw Inlet Wire Guide Loosen screw. Slide tip as close to drive rolls as possible without touching. Tighten screw. 3 Anti-Wear Guide Install guide as shown. 1 4 Drive Roll Install correct drive roll for wire size and type. Tools Needed: 5 5/64 in Drive Roll Securing Nut Turn nut one click to secure drive roll. 7/16 in 4 ST-150 227-C 2-9.
2-11.
2-13. Threading Welding Wire 1 2 3 4 5 6 7 4 7 Wire Spool Welding Wire Inlet Wire Guide Pressure Adjustment Knob Drive Roll Outlet Wire Guide Gun Conduit Cable Lay gun cable out straight. Tools Needed: 1 2 3 5 6 . Hold wire tightly to keep it from unraveling. 4 in (102 mm) 6 in (150 mm) Open pressure assembly. Pull and hold wire; cut off end. Push wire thru guides into gun; continue to hold wire. Tighten Close and tighten pressure assembly, and let go of wire.
SECTION 3 – OPERATION 3-1. Controls 1 2 3 4 5 6 7 8 1 Parameter Increase Button Parameter Decrease Button Parameter Display Parameter Select Button Mode Select Button Mode Display Pilot Light Power Switch 7 2 8 6 5 4 3 Ref. ST-147 589-A / Ref. ST-174 835-A 3-2. Installing Receptacle Module For Use With A Spool Gun (Optional) Remove existing options panel. 1 Module 2 Plug PLG9 3 Plug PLG7 Connect PLG9 to PLG7. 2 1 3 Slide module into upper front panel where options panel was removed.
SECTION 4 – PROGRAMMING THE MICROPROCESSOR NOTE Experiment with the microprocessor. If you have difficulties, reset the unit according to Section 4-10, and unit returns to original factory settings. 4-1. Mode Selection Button 1 1 Mode Display 2 Mode Select Button Press Mode button to move indicator >. Ma t e r i a l >We l d T i me r Dua l Sc hd 2 Ma t e r i a l We l d >T i m e r Dua l Sc hd Ma t e r i a l We l d T i me r >D u a l S c h d >M a t e r i a l We l d T i me r Dua l Sc hd Ref.
4-2. Parameter Select Button 1 1 2 2 Parameter Display Moving Line Moving line is under value that can be changed. 3 Parameter Select Button Press Parameter button to move indicator >. Ma t e r i a l >We l d T i me r Dua l Sc hd >M e m o r y O f f 122 I PM 17 . 5 Vo l t Memo r y O f f I PM >1 2 2 17 . 5 Vo l t Memo r y O f f 122 I PM >1 7 . 5 V o l t 3 Ref. ST-147 589-A 4-3. Parameter Increase And Decrease Buttons 1 Increase Button Press buttons to change value on moving line.
4-4. Weld Mode 1 Weld Mode Select Weld to set wire speed and volts. Unit must be in Weld mode to select program Memory number. 2 1 Ma t e r i a l >We l d T i me r Dua l Sc hd Memory Memory can store up to 9 weld programs. On power up, “Memory Off” is displayed. Values are a copy of last weld program used. >M e m o r y O f f 122 I PM 17 . 5 Vo l t 2 Value changes in “Memory Off” do not affect other programs. 3 3 4 Value can be set between 50 and 670 ipm (1.3 to 17.0 mpm).
4-6. Dual Schedule Mode And Gun Switches 1 Ma t e r i a l We l d T i me r >D u a l S c h d Sw i >M e m o Sw i Memo t r t r ch y ch y A 1 B 2 2 2 Switch A Or B Memory number is preset weld program. 3 Increase/Decrease Switch Increases or decreases wire feed speed set by welding power source/ wire feeder. Activates weld program A or B. 1 Wire Speed (B) – Dual Schedule Mode Select Dual Schedule to set any combination of the 9 available memories for dual scheduling.
4-8. Setting Language, Wire Speed Units, And Burnback 1 1 Mode And Parameter Select Buttons 2 Power Switch 2 Mode Parameter Select Select Press and hold down both buttons while turning On unit. 3 Language Select any one of six languages by pressing Increase or Decrease button. The Language choices are: English (default setting), French, German, Italian, Spanish, and Japanese.
4-9. Using One Switch To Control Voltage And Wire Speed (Synergic Welding) Ma t e r i a l >We l d T i me r Dua l Sc hd Set up weld program. See Section 4-4. >M e m o r y 3 125 I PM 18 . 6 Vo l t Press Parameter Select 3 Times Memo r y 3 I PM >1 2 5 >1 8 . 6 V o l t Ma t e r i a l >We l d T i me r Dua l Sc hd Memo r y 3 >1 2 5 I PM >1 8 . 6 V o l t Gun Trigger .
SECTION 5 – MAINTENANCE AND TROUBLESHOOTING 5-1. Routine Maintenance Y Disconnect power before maintaining. 3 Months Replace unreadable labels. Repair or replace cracked weld cable. Clean and tighten weld terminals. 6 Months Blow out or vacuum inside. During heavy service clean monthly. OR 5-2. Circuit Breaker CB1 1 Circuit Breaker CB1 If CB1 opens, wire feeding stops. 2 Welding Gun Check gun liner for blockage or kinks.
5-4. Replacing Gun Contact Tip Y Turn Off power. 1 2 Nozzle Contact Tip Cut off welding wire at contact tip. Remove nozzle. Remove contact tip and install new contact tip. Reinstall nozzle. 2 1 Tools Needed: ST-149 326-B 5-5. Aligning Drive Rolls And Wire Guide Y Turn Off power. Horizontal Alignment Correct 4 Incorrect 5 3 2 1 6 View is from top of drive rolls looking down with pressure assembly open.
5-7. Cleaning Or Replacing Gun Liner Y Disconnect gun first. Tools Needed: 3/8 in Head tube Remove nozzle, contact tip, adapter, and wire outlet guide. Wire Outlet Guide 3/8 in Remove liner. Lay gun cable out straight before installing new liner. To Reassemble Gun: Blow out gun casing. Insert new liner. Install and tighten wire outlet guide. Cut liner off 3/4 in (20 mm) (3/8 in [9.5 mm] for aluminum) from head tube. Install adapter, contact tip, and nozzle. Ref.
5-8. Replacing Switch And/Or Head Tube Y Disconnect gun first. 3 1 4 2 Remove handle locking nut. Secure head tube in vice. 5 Remove shock washers from front and rear of head tube. 6 Slide handle. Remove switch housing. Note: If installing new switch, push switch lead connectors onto terminal of new switch (polarity is not important). Install switch back into handle, and secure with handle locking nut. If replacing head tube, continue to end of figure. Loosen jam nut.
5-9. Troubleshooting Trouble No weld output; wire does not feed. Remedy Be sure line disconnect switch is On (see Section 2-12). Replace building line fuse or reset circuit breaker if open (see Section 2-12). Reset circuit breaker CB1 (see Section 5-2). Secure gun trigger connections (see Section 2-5). Check and replace Power switch if necessary. Have Factory Authorized Service Agent check all board connections and main control board. No weld output; wire feeds. Thermostat TP1 open (overheating).
5-10. Selftest Procedure 1 2 Press and hold down both buttons while turning On unit. 2 1 Mode And Parameter Select Buttons Power Switch Mode Parameter Select Select 3 Switch A This checks the increase position. 4 switch gun switch Switch B This checks the decrease position. 5 gun Trigger This checks the gun trigger. 6 Press Mode Select 3 Times 7 8 u f r t age eed y es t > S wi t c h Gun Increase Switch A Overload This checks for an overload condition.
5-11. Troubleshooting Displays Trouble Release Trigger displayed. Remedy Release gun trigger. Check gun trigger and leads. There is high frequency in the area of the welder. Turn it off or move welder. Release Remote displayed. Release spool gun or remote control trigger. Check spool gun trigger and leads according to spool gun Owner’s Manual. Check remote control switch and switch leads according to unit Owner’s Manual. There is high frequency in the area of the welder. Turn it off or move welder.
SECTION 6 – ELECTRICAL DIAGRAM SC-168 541-A Figure 6-1.
. Hardware is common and 16 15 14 SECTION 7 – PARTS LIST 19 20 Fig 7-3 Fig 7-6 25 1 2 24 3 23 22 4 Fig 7-2 21 6 7 5 8 9 10 Fig 7-5 8 11 7 12 17 13 18 not available unless listed. ST-148 324-E Figure 7-1.
Item No. Dia. Mkgs. Part No. Description Quantity Figure 7-1. Main Assembly . . . 1 . . . . . . . . . . . 148 597 . . . 2 . . . . . . . . . . . 146 168 . . . 3 . . PLG7 . . 083 526 . . . 4 . . . . . . . . . . . . Fig 7-2 . . . 5 . . . . T1 . . . 144 043 . . . 5 . . . . T1 . . . 150 381 . . . 5 . . . . T1 . . . 150 382 . . . . . . . . . . . . . . . . . 143 853 . . . . . . . . . . . . . . . . . 150 326 . . . . . . . . . . . . . . . . . 150 314 . . . . . . . . . TP3 . . . 121 497 . . . 6 . . . . . . . . .
. Hardware is common and not available unless listed. 1 2 3 4 5 6 7 8 9 7 6 34 10 11 33 Fig 7-4 35 32 12 13 14 31 15 30 16 26 18 19 20 25 24 17 29 27 28 21 23 22 ST-148 325-C Figure 7-2.
Item No. Dia. Mkgs. Part No. Description Quantity Figure 7-2. Baffle, Center w/Components (Fig 7-1 Item 4) . . . 1 . . . . . . . . . . . 058 427 . . . 2 . . . . . . . . . . . 085 980 . . . 3 . . . . . . . . . . . 605 941 . . . 4 . . . . . . . . . . . 057 543 . . . 5 . . . . . . . . . . . 057 971 . . . 6 . . . . . . . . . . . 010 191 . . . 7 . . . . . . . . . . . 058 628 . . . 8 . . . . . . . . . . . 057 745 . . . 9 . . . . . . . . . . . 058 428 . . . 10 . . . . . . . . . . . 177 307 . . . 11 . . . . .
Item No. Dia. Mkgs. Part No. Description Quantity Figure 7-3. Panel, Front w/Components (Fig 7-1 Item 24) . . . 1 . . . . . . . . . . . . . 147 582 . . . . . 2 . . . . . . . . . . . . . 147 791 . . . . . 3 . . . . PC5 . . . . 182 021 . . . . . 4 . . . . PC1 . . . . 147 472 . . . . . . . . . . . PLG8 . . . 143 322 . . . . . . . . . . . . . . . . . . . . . . 113 746 . . . . . 5 . . . . . . . . . . . . . 143 974 . . . . . 6 . . . . C9 . . . . . 146 158 . . . . . 6 . . . . C10 . . . . 175 719 . . . . . 6 .
Item No. Dia. Mkgs. Part No. Description Quantity Figure 7-4. Wire Drive And Gears (Fig 7-2 Item 35) . . . 1 . . . . . . . . . . . 602 009 . . . 2 . . . . . . . . . . . 172 075 . . . 3 . . . . . . . . . . . 166 072 . . . 4 . . . . . . . . . . . 010 224 . . . 5 . . . . . . . . . . . 182 788 . . . 6 . . . . . . . . . . . 085 242 . . . 7 . . . . . . . . . . . 085 244 . . . 8 . . . . . . . . . . . 010 231 . . . 9 . . . . . . . . . . . 085 243 . . . 10 . . . . . . . . . . . 166 071 . . . 11 . . . . . . . .
Table 7-1.Drive Roll And Wire Guide Kits Note Base selection of drive rolls upon the following recommended usages: 1 2 3 4 5 V-Grooved rolls for hard wire. U-Grooved rolls for soft and soft shelled cored wires. U-Cogged rolls for extremely soft shelled wires (usually hard surfacing types). V-Knurled rolls for hard shelled cored wires. Drive roll types may be mixed to suit particular requirements (example: V-Knurled roll in combination with U-Grooved). Wire Diameter Drive Roll Part No.
Item No. Part No. Description Quantity Figure 7-6. M-25M Gun (Fig 7-1 Item 25) ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1 1 1 1 1 1 1 2 2 2 2 3 4 5 6 7 8 9 10 11 12 1 . . . ♦169 724 . . . ♦169 725 . . . ♦169 726 . . . ♦169 727 . . . ♦176 238 . . . ♦176 240 . . . ♦176 242 . . . ♦087 299 . . . ♦000 067 . . . ♦000 068 . . . ♦000 069 . . . . . 169 728 . . . . . 169 729 . . . . . 170 467 . . . . . 170 468 . . . . . 169 730 . . . . . 169 731 . . . . . 169 738 . .
Item No. Part No. Description Quantity Figure 7-6. M-25M Gun (Fig 7-1 Item 25) (Continued) . . . 13 . . . . . 172 018 . . . 14 . . . . . 169 735 . . . 15 . . . . . 169 742 . . . 16 . . . . . 169 743 . . . 17 . . . . . 170 469 . . . 18 . . . . . 169 746 . . . 19 . . . . . 172 690 . . . 20 . . . . . 172 691 . . . . . . . . . . . 602 063 . . . 21 . . . . . 169 741 . . . 22 . . . . . 180 431 . . . 23 . . . . . 173 521 . . . 24 . . . . . 079 974 . . . 25 . . . ♦172 257 . . . 25 . . . ♦172 258 . . . 26 . . .
Notes
Notes
Notes
OPTIONS AND ACCESSORIES M40AL GUN (#169 608) For welding with aluminum wire. Rated 525 amps at 60% duty cycle or 275 amps at 100% duty cycle using argon gas. Gun designed to run 3/64 in (1.2 mm) wire. 10 ft (3.0 m). SPOOLMATICE 30A SPOOL GUN (#130 831) Ideal for aluminum welding jobs. 200 amp, 100% duty cycle, air-cooled, 1 lb spool gun with 30 ft (9.1 m) cable assembly. Plugs into Receptacle Module 2. For detailed information, see Spoolmatic literature, Index No. M/1.2.
Effective January 1, 2000 (Equipment with a serial number preface of “LA” 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.
Owner’s Record Please complete and retain with your personal records. Model Name Serial/Style Number Purchase Date (Date which equipment was delivered to original customer.) Distributor Address City State Zip For Service Call 1-800-4-A-Miller or see our website at www.MillerWelds.com to locate a DISTRIBUTOR or SERVICE AGENCY near you. Always provide Model Name and Serial/Style Number.
