Miller Electric CST 250 guide

	Trouble	Possible Causes	Remedy

	Erratic or improper weld output.	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).

	Wandering arc	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).

	Tungsten electrode oxidizing and not	Shielding gas blown away from weld	Shield weld zone from drafts.
	remaining bright after conclusion of	zone.
	weld.
	weld.	Inadequate postflow time.	Allow adequate postflow time to shield tungsten while it
		Inadequate postflow time.	Allow adequate postflow time to shield tungsten while it
			cools, after welding stops.

		Loose or leaking gas fittings.	Check and tighten all gas fittings (see Section 3-7).

		Water in torch.	Refer to torch manual.

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Miller Electric CST 250 manual Use proper size and type of weld cable see Section

Contents

Description OM-2237 206 035HProcesses From Miller to You Table of Contents Page Marks a special safety message Symbol UsageArc Welding Hazards Electric Shock can kill Welding can cause fire or explosion ARC Rays can burn eyes and skinFlying Metal can injure eyes Buildup of GAS can injure or kill California Proposition 65 Warnings About Pacemakers Principal Safety StandardsEMF Information − Consignes DE Sécurité − À Lire Avant Utilisation Signification des symbolesLES Décharges Électriques peuvent être mortelles LES Fumées ET LES GAZ peuvent être dangereux LES Particules Projetées peu- vent blesser les yeux LE Soudage peut causer un incen- die ou une explosionLES Pièces Chaudes peuvent cau- ser des brûlures graves LE Bruit peut affecter l’ouïe LA Chute DE L’APPAREIL peut blesser Risque D’INCENDIE OU D’EXPLO’EMPLOI Excessif peut Faire LES Pièces Mobiles peuvent cau- ser des blessures Consignes relatives aux stimulateurs cardiaques Principales normes de sécuritéInformation sur les champs électromagnétiques Duty Cycle And Overheating − InstallationSpecifications 100 150 200 250 300 350 Stick Smaw Volt-Ampere Curves Amps TIG Gtaw Volt-Ampere Curve Location And Airflow Dimensions And WeightSelecting a Location 150 ft 200 ft 250 ft Weld Output Terminals And Selecting Cable Sizes350 ft 400 ft 45 m 60 m 70 m 90 m 105 m 120 m Terminals Amperes Positive + Weld Output Terminal 50/60 Hz Single-Phase 50/60 Hz Three-Phase Electrical Service GuideStick Dcep Direct Current Electrode Positive Connections Input Voltage Selecting 230 Volts AC Single/Three Phase Input Voltage Relinking Board Connection For 460 575 VAC Input Power Selecting 460 575 Volts AC Three Phase Input Voltage For three-phase operation Connecting Input PowerFor single-phase operation = GND/PE Controls − Operation Lift-ArctTIG Normal Process Select Control Lift-ArcStart Procedure Stick Start Procedure − Scratch Start TechniqueLift-Arc Start Application Remote 14 Receptacle Information Amperage ControlFan-On-Demand Rack Mounting Routine Maintenance − Maintenance and TroubleshootingBlowing Out Inside Of Unit Months Trouble Possible Causes Remedy Troubleshooting Use proper size and type of weld cable see Section Circuit Diagram − Electrical Diagrams Selecting Tungsten Electrode Safety Information About Tungsten− Selecting and Preparing Tungsten Electrode Tungsten Electrode OM-2237 Main Assembly − Parts List CAPACITOR,ELCTLT 2400 UF 500 VDC can 2.5 DIA Panel, Front w/Components Panel, Rear w/Components Magnetics Subassembly Heat Sink Assembly, Output Diode Base Assembly Heat Sink Assembly, Input Page Support Service Miller Electric Mfg. Co Owner’s Record