Miller Gold Seal 420, Owner'S Manual

Page 1: ... to the operator For help call your distributor or MILLER ELECTRIC Mfg Co P O Box 1079 Appleton WI 54912 414 734 9821 OWNER S MANUAL October 1997 Form OM 174 470B Effective With Serial No KH531011 Gold Seal Model 420 CV DC Welding Power Source Wire Feeder For FCAW And GMAW Welding 90 Amperes 18 Volts At 20 Duty Cycle Uses 115 Volts AC Single Phase Input Power Overheating Short Circuit And Motor Ov...

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Page 3: ...s around your body 9 Ground the workpiece to a good electrical earth ground 10 Do not touch electrode while in contact with the work ground circuit 11 Use only well maintained equipment Repair or replace damaged parts at once 12 Wear a safety harness to prevent falling if working above floor level 13 Keep all panels and covers securely in place ARC RAYS can burn eyes and skin NOISE can damage hear...

Page 4: ...ding electrode to touch any cylinder 5 Use only correct shielding gas cylinders regulators hoses and fittings designed for the specific application maintain them and associated parts in good condition 6 Turn face away from valve outlet when opening cylinder valve 7 Keep protective cap in place over valve except when cylinder is in use or connected for use 8 Read and follow instructions on compress...

Page 5: ... 36 kg Welding Gun Rated Output Air Cooled 160 Amperes At 60 Duty Cycle Using CO2 Shielding Gas Cable Length 10 ft 3 m 1 1 Volt Ampere Curve And Duty Cycle Chart CAUTION USING GUN BEYOND DUTY CYCLE RATING can damage gun Do not use gun beyond rated amperage when using CO2 shielding gas Use gun at 30 duty cycle when using mixed shielding gas wfwarn8 1 10 91 ssb1 1 10 91 SB 124 646 A sb1 3 10 91 SB 1...

Page 6: ...ll Shut off shielding gas supply when not in use warn4 1 9 91 Tools Needed 1 1 8 5 8 in 7 8 3 1 2 1 2 3 OR 5 4 6 Argon Gas Or Mixed Gases Chain gas cylinder to running gear wall or other stationary support so cylinder cannot fall and break off valve 1 Cap 2 Cylinder Valve 3 Cylinder 4 Regulator Flowmeter 5 Gas Hose Connection Fitting has 5 8 18 right hand threads 6 Flow Adjust Typical flow rate is...

Page 7: ...r Label 2 Polarity Jumper Links Always read and follow welding wire manufacturer s recommended polarity Close door Ref ST 155 506 A Tools Needed 3 8 in STRAIGHT POLARITY DCEN REVERSE POLARITY DCEP GUN POLARITY CHANGEOVER For Flux Cored Wires FCAW Process For Solid Steel Or Wires GMAW S 116 599 Aluminum Process 1 2 Figure 2 3 Gun Polarity Connections 2 5 Installing Welding Gun 1 Gun Securing Nut 2 ...

Page 8: ...nd and turn while using a wrench to adjust nut When a slight force is needed to turn spool tension is set Loosen wire from spool cut off bent wire and pull 6 in 150 mm of wire from spool 3 Pressure Adjustment Open pressure assembly 4 Wire Inlet Guide 5 Drive Roll 6 Wire Outlet Guide Thread wire through inlet guide along drive roll groove and into outlet guide Close pressure assembly Lay gun cable ...

Page 9: ...th a correct shade of filter see ANSI Z49 1 sb3 1 10 91 1 2 3 Figure 3 1 Safety Equipment 1 Power Switch Use switch to turn unit On and Off 2 Wire Speed Control Use control to select a wire feed speed As Voltage switch setting increases wire speed range also increases The numbers around the control are not a wire feed speed see last page of Parts List 3 Voltage Switch Use switch to select an arc v...

Page 10: ...nd tighten connections Replace unreadable labels Every 6 months Blow out or vacuum inside of unit 4 1 Overload Protection READ SAFETY BLOCKS at start of Section 4 before proceeding WARNING A Overheating Thermostat TP1 protects the unit from damage due to overheating If main transformer gets too hot TP1 opens and weld output stops but fans keep running to cool transformer Wait several minutes befor...

Page 11: ...crew 7 Bearing Remove bearing as shown Install new bearing and secure with screw Reinstall arm onto pin and secure with cotter pin 8 Setscrew 9 Smooth Groove For Hard Wire 10 Drive Roll Remove drive roll as shown Use a wire brush to clean drive roll Push drive roll onto shaft with desired groove in Turn drive roll so one setscrew faces flat side of shaft and tighten both setscrews 11 Knurled Groov...

Page 12: ...rive roll Remove gun and cut liner off Reinstall gun so that liner is as close as possible to drive rolls without touching Thread welding wire see Section 2 6 Close door Ref ST 155 506 A ST 155 509 A Tools Needed 3 8 5 16 in 2 1 3 4 5 7 7 6 6 Figure 4 3 Gun Maintenance 4 4 Troubleshooting READ SAFETY BLOCKS at start of Section 4 before proceeding WARNING Welding Trouble Remedy Section No weld outp...

Page 13: ...wire inlet guide or liner if dirty or plugged 4 2 4 3 Replace drive roll or pressure bearing if worn or slipping 4 2 Secure gun trigger leads or repair leads or replace trigger switch 2 5 Check and replace F1 4 1B Check and clear any restrictions at drive assembly and liner 4 2 4 3 Have nearest Factory Authorized Service Station Service Distribu tor check drive motor SECTION 5 ELECTRICAL DIAGRAM S...

Page 14: ...OM 174 470 Page 10 NOTES ...

Page 15: ... 11 SECTION 6 PARTS LIST 16 17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 18 19 20 21 22 23 24 25 26 27 28 29 31 32 33 30 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Fig 6 2 52 ST 155 532 A Figure 6 1 Main Assembly ...

Page 16: ...Cord Set 111 443 Bushing cord set 000 101 Rheostat 097 922 Knob 111 997 Rocker Switch SPST 111 897 Rotary Switch 127 023 Knob 155 530 Case 182 488 Nameplate 111 644 Bushing 875mtg 025 338 Bushing 625mtg 40 153 722 Side Panel 41 125 552 Thermostat NC 42 147 676 Transformer 43 181 649 Resistor 44 090 288 Varistor 45 162 264 Capacitor 46 022 160 Clamp 47 118 457 Stabilizer 48 019 663 Foot 49 600 325 ...

Page 17: ... Type ER70S 6 Mild Steel 75 Argon 25 CO2 20 cfh ER 308 Stainless Steel Tri Mix 20 cfh Aluminum Argon 30 cfh Voltage Wire Speed Voltage Wire Speed Voltage Wire Speed Voltage Wire Speed Voltage Wire Speed Voltage Wire Speed Voltage Wire Speed Do not change VOLTAGE switch position while welding WIRE SPEED value in table is a starting value only and WIRE SPEED control setting can be fine tuned during ...

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Page 19: ... by Miller but manufactured by others such as engines or trade accessories These items are covered by the manufacturer s warranty if any 2 Consumable components such as contact tips cutting nozzles contactors brushes slip rings relays or parts that fail due to normal wear 3 Equipment that has been modified by any party other than Miller or equipment that has been improperly installed improperly op...

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