Sealey POWERMIG300i 300A Professional Gas/Gasless MIG/MMA/TIG Inverter Welder

Important Safety Instructions

Thank you for purchasing a Sealey product. Read these instructions carefully. Note the safe operational requirements, warnings, and cautions. Use the product correctly and with care for the purpose for which it is intended. Failure to do so may cause damage and/or personal injury and will invalidate the warranty. Keep these instructions safe for future use.

General Safety Precautions:

• Refer to instructions.
• Wear a welding mask.
• Wear protective gloves.
• Wear safety footwear.
• Beware of electrical shock hazard.
• Beware of hot surfaces.
• Do not use in the vicinity of a pacemaker.
• Welding sparks can cause explosions or fire.
• Wear protective clothing.
• Arc rays can burn eyes and injure skin.
• Breathing welding fumes can be hazardous to your health.
• Do not use in rain.

Electrical Safety:

• Ensure all electrical equipment and appliances are safe before use.
• Inspect power supply leads, plugs, and all electrical connections for wear and damage.
• Ensure cable insulation is safe before connecting to the power supply.
• DO NOT use worn or damaged cables, plugs, or connectors.
• Ensure faulty items are repaired or replaced by a qualified electrician.
• If the cable or plug is damaged during use, switch off the electricity supply and remove from use.
• Ensure repairs are carried out by a qualified electrician.
• Sealey recommends the use of an RCD (Residual Current Device).
• Ensure the appliance voltage rating suits the power supply and the plug is fitted with the correct fuse.
• DO NOT pull or carry the appliance by the power cable.
• DO NOT pull the plug from the socket by the cable.

General Safety:

• Welding power sources are not suitable for use in rain or snow.
• Risk of electric shock: Electric shock from welding electrode can kill.
• The output is rated at 20°C ambient temperature; welding time may be reduced at higher temperatures.
• DO NOT weld in the rain or snow.
• WARNING! DO NOT place power source on a tilted plane; this may lead to unit toppling over. DO NOT use on uneven surfaces.
• Wear dry insulating gloves.
• DO NOT touch electrode with bare hands.
• DO NOT wear wet or damaged gloves.
• Protect yourself from electric shock by insulating yourself from the workpiece.
• DO NOT open the equipment enclosure.
• WARNING! Welding fumes: Breathing welding fumes can be hazardous to your health. Keep your head out of the fumes. Use in an open area and use a ventilating fan to remove fumes. Wear hat and safety glasses. Use ear protection and button shirt collar.
• WARNING! Risk induced by welding sparks: Welding sparks can cause explosion or fire. Keep flammables away from welding. DO NOT weld near flammables. Have a fire extinguisher nearby. DO NOT weld on drums or any closed containers.
• WARNING! Risk induced by the arc: Arc rays can burn eyes and injure skin. Use welding helmet with correct shade of filter. Wear complete body protection.
• WARNING! Risk induced by electromagnetic fields: Welding current produces electromagnetic fields. DO NOT use with medical implants. Never coil welding cables around your body. Route welding cables together.
• The operator should be adequately trained and informed about risks, protection measures, and emergency procedures.
• DANGER! Unplug the welder from the mains power supply before performing maintenance or service.
• Keep the welder and cables in good working order. Take immediate action to repair or replace damaged parts.
• Use genuine parts and accessories only.
• Use an air hose to regularly blow out any dirt from the liner and keep the welder clean.
• Check and spray the gas cup and contact tip regularly with anti-spatter spray.
• Locate welder in an adequate working area with adequate ventilation.
• Keep working area clean, tidy, and free from unrelated materials. Ensure adequate lighting and a fire extinguisher is at hand.
• Remove ill-fitting clothing, ties, watches, rings, and other loose jewellery, and contain long hair.
• Ensure the workpiece is correctly secured.
• Avoid unintentional contact with workpiece.
• Keep non-essential persons away from the working area.
• Operators must receive adequate training. The welder must only be operated under supervision.
• Stand correctly keeping good footing and balance. Ensure the floor is not slippery and wear non-slip shoes.
• Turn voltage switch to "0" or off when not in use.
• DO NOT operate the welder if its cables are damaged and DO NOT attempt to fit any non-genuine torches, components, or parts.
• DO NOT get welder wet or use in damp or wet locations or areas where there is condensation.
• DANGER! DO NOT weld near inflammable materials, solids, liquids, or gases, and DO NOT weld containers or pipes which have held flammable materials or gases, liquids or solids. Avoid operating on materials cleaned with chlorinated solvents or near such solvents.
• DO NOT touch any live metal parts of the torch or electrode while the machine is switched on.
• DO NOT weld on any containers which are under pressure.
• DO NOT pull the welder by the mains cable or by the umbilical connection cable.
• DO NOT pull the wire feed unit by the umbilical connection cable or by the torch cable. Protect cables from sharp or abrasive items, and DO NOT stand on cables or leads.
• DO NOT place cables where they endanger others.
• DO NOT touch the torch or workpiece immediately after welding as they will be very hot. Allow to cool.
• DO NOT operate welder while under the influence of drugs, alcohol or intoxicating medication, or if fatigued.
• When not in use, store the welder in a safe, dry, childproof area.
• Provide adequate ventilation or facilities for the removal of welding fumes.
• WARNING! Electromagnetic interference: The electromagnetic fields generated by the welding process may interfere with the operation of electrical and electronic equipment. Users of vital electronic and electrical devices such as pacemakers and respirators are advised not to remain in the vicinity of an operating welding machine. If in doubt seek medical advice before entering a welding area. Users of such devices should not operate the welding machine. This welder complies with the requirements of the technical standard for the use of this type of product, only and exclusively in industrial environments and for professional purposes. It is not guaranteed to meet electronic compatibility requirements in the home.
• WARNING! Gas safety: Store gas cylinders in a vertical position only and ensure the storage area is correctly secured. DO NOT store gas cylinders in areas where temperature exceeds 50°C. DO NOT use direct heat on a cylinder. Keep gas cylinders cool. DO NOT attempt to repair or modify any part of a gas cylinder or valve, and DO NOT puncture or damage a cylinder. DO NOT obscure or remove any official labels from a cylinder. Always check the gas identity before use. Avoid getting gas cylinders oily or greasy.
• DO NOT try to lift or handle cylinder by its cap, guard or valve. Always keep caps and guards in place and close valve when not in use. The gas cylinder is heavy; use mechanical lifting equipment. Ensure the cylinder is correctly situated on the welder base stand and secured with chain.
• Risk assessment: Where welding is unavoidable in awkward situations such as in confined spaces, in environments with increased risk of electric shock, and in the presence of flammable or explosive materials, a risk assessment must be carried out by an experienced and qualified expert professional in consultation with providers of emergency services to ensure that operations are carried out in the safest possible way.

Introduction

This is a multi-process IGBT inverter Gas/Gasless MIG/TIG/MMA welder suitable for professional fabricators and workshops, as well as mechanics and technicians. With a maximum output of 300A, it is ideal for welding a large variety of metals including Steel, Stainless Steel, and Aluminium up to 12mm. It features 2T/4T torch trigger function for greater precision during longer welds, an easy-to-read digital amp and voltmeter display, and protection against short circuit, overheating, and over-current. It has large rear wheels and a low gas cylinder tray for ease of loading and maximum stability.

Supplied with a 2m power cable, 2m earth clamp, 3m MIG torch, and 2m electrode holder.

Contents

Specification

Operation

Modes and Materials

Feed Wheel Type and Welded Materials

Polarity Settings

Figure 1: TIG welding setup showing welding rod, torch, and connection to the machine.

Figure 2: MMA welding setup showing electrode, torch, and connection to the machine.

Figure 3: FLUX CORED welding setup showing wire, torch, and connection to the machine.

Figure 4: MIG/MAG welding setup showing wire, torch, and connection to the machine.

Figure 5: Control panel layout with numbered components.

Key to Fig. 5:

Short Circuit Protection: When a short circuit is detected, the machine turns off the output current. Avoid short circuit between the electrode and the workpiece. If a short circuit occurs, remove it quickly. If necessary, shut down the machine.

2T / 4T: These are two ways of on-off control of welders. 2T/4T is commonly used for TIG, MIG, and PLASMA CUTTING.

• 2T: Press the welding torch and the machine starts to work; Release the torch and the machine stops working.
• 4T: Press the welding torch for the first time, and the machine enters the initial current; Loosen the welding torch, the machine enters the working current; Press the welding torch again, the machine enters the end up current; Loosen again and the machine stops working.

Pre Gas and Post Gas: Before welding, the machine delivers gas (pre gas) to ensure a protective gas atmosphere. After welding, the torch continues to transport gas (post gas) to reduce the temperature of the weldment surface and prevent high-temperature workpiece and air chemical reactions.

SYN-JUST FOR MIG/MAG: This feature provides synergistic parameters for welding. Select certain parameters on the panel, and the machine will recommend appropriate welding current and voltage. Fine-tuning is recommended based on personal preference and welding speed.

MMA (ARC FORCE): When the electrode is too close to the workpiece, the machine increases the output current, causing the electrode to melt faster. ARC FORCE helps prevent short circuits.

MIG/MAG (INDUCTANCE): Adjusting the inductance changes the hardness of the welding arc. Lower inductance results in a harder arc and more splash. Higher inductance results in a softer arc and less splash.

Welding Procedure:

1. Specify the material to be welded, thickness, and welding mode.
2. Select appropriate tooling.
3. Connect power, gas, wire, or electrode and torch. Turn on the machine.
4. Select the appropriate mode on the screen.
5. Adjust current (or voltage, wire feed speed).
6. Determine the process (e.g., 4T mode, pulse).
7. Start welding or cutting.
8. During welding, adjust current, voltage, wire feed speed, and process parameters as needed for a satisfactory welding effect.
9. For machines with post gas function, do not immediately remove the torch after welding; complete the post gas.
10. DO NOT immediately touch the workpiece and welding torch.
11. Turn off the power, turn off the gas, clean up the welding machine, and keep it safe.

MIG/MAG/FLUX CORED: The diameter of the welding wire, the wire feed wheel, and the conductive nozzle should be the same. Ensure the nozzle at the head of the torch is correctly installed.

Wire Feeder (Fig. 6):

• Select and install appropriate wire feed wheels and fit to the drive shaft.
• Release idler arms by unscrewing the idler arm clamps.
• Install a suitable diameter reel of suitable material onto the shaft.
• Thread the wire through the wire feed mechanism.
• Lock idler arms using the clamps.
• Adjust the feed tensioner as necessary.

Figure 6: Wire feeder components including feed tensioner, idler arm clamps, and idler arms.

Thermal control can be achieved by adjusting voltage, current, or feed speed.

Troubleshooting

Mode-Specific Troubleshooting

Maintenance

• DO NOT take apart the machine without permission, it may damage the machine.
• When moving the machine, make sure the power is off.
• DO NOT block the fan of the running machine or touch the fan position. Check the ventilation before each use.
• Always start by reading the manual for your specific welding equipment.
• Regularly clean your welding equipment to remove any dirt, debris, or metal shavings. Use a soft brush or compressed air to clean cooling fans, vents, or filters.
• Inspect welding cables regularly for any damage or wear and tear. Replace any cables that show signs of damage, such as fraying or cracks.
• Check consumables (tips, nozzles, electrodes) regularly for wear and tear. Replace damaged or worn consumables.
• Check the gas cylinder regularly for pressure and leaks. Replace if empty or damaged.
• When not in use, store your welding equipment in a clean, dry, and safe location. Keep covered to protect from dust, moisture, and other environmental factors.
• Check the welding machine output wiring specifications, firmness, and cable connection screws for rust and oxidation.
• DO NOT short-circuit the conductive nozzle and the workpiece. This will burn out the conductive nozzle.

WARNING! Ensure the unit is disconnected from the mains power supply before performing any maintenance or service.

• Regularly check all welding cables and secondary terminals for good order and correct connection. Check for overheating during welding.
• Check that the gas hose connections are tight and that there are no gas leaks.

Wire Feed Unit:

• Check the wire feed unit at regular intervals. The feed roller wire guide is important for consistent results. Clean rollers weekly, especially the feedroller groove.
• Changing Feed Roller/Rollers: Set up feed rollers according to the wire size required.

Torch:

• Make regular checks on the gas pipe and connector seals.
• Protect the torch cable assembly from mechanical wear. Avoid contact with hot surfaces.
• Every time the wire reel is changed, blow out the wire-guide hose using dry compressed air (max. 5 bar).
• Before using the welding machine, always check the torch terminal parts for wear and ensure correct assembly (nozzle, contact pipe, gas diffuser).

Contact Tip: The contact tip is a consumable item and must be replaced when the hole becomes enlarged or oval. Keep the contact tip free from spatter to ensure an unimpeded flow of gas.

Gas Cup: To keep the contact tip free from spatter, Sealey recommends using Sealey anti-spatter spray (MIG/722307).

Internal Maintenance/Inspection:

INTERNAL INSPECTION AND MAINTENANCE OPERATIONS SHOULD BE CARRIED OUT ONLY AND EXCLUSIVELY BY SKILLED OR AUTHORISED ELECTRICAL/MECHANICAL TECHNICIANS.

WARNING! BEFORE REMOVING THE WELDING MACHINE PANELS AND WORKING INSIDE THE MACHINE, MAKE SURE THE WELDING MACHINE IS SWITCHED OFF AND DISCONNECTED FROM THE MAIN POWER SUPPLY OUTLET.

• Inspect the welding machine regularly and remove dust deposited on the transformer and rectifier using a jet of dry compressed air (max. 10 bar).
• DO NOT direct the jet of compressed air on the electronic boards; clean them with a very soft brush or suitable solvents.
• At the same time, make sure the electrical connections are tight and check the wiring for damage to the insulation.
• Re-assemble the panels and screw the fastening screws down.

WARNING! Never carry out welding operations while the welding machine is open.

End of Life

Dispose of the unit and accessories in accordance with Local and National regulations, WEEE Regulations, and Environment Protection footers.

Rating Plate

The rating plate on the front panel provides the following data:

1. BS/EU standard relating to arc welding equipment safety and construction.
2. Three-phase transformer.
3. Symbol indicating welding with a continuous flow of welding wire.
4. Symbol for three-phase AC supply.
5. Rating of internal protection provided by casing.
6. Output U0: Rated minimum and maximum no load voltage.
7. U2: Current and corresponding voltage.
8. Welding ratio based on a 10-minute cycle (e.g., 20% indicates 2 minutes welding and 8 minutes rest; 100% indicates continuous welding).
9. Mains Supply: U1 Rated supply voltage and frequency, I1max Maximum current, I1eff Maximum effective current.

WEEE Regulations: Dispose of this product at the end of its working life in compliance with the EU Directive on Waste Electrical and Electronic Equipment (WEEE). Contact your local solid waste authority for recycling information.

Environment Protection: Recycle unwanted materials instead of disposing of them as waste. Sort all tools, accessories, and packaging for recycling. Dispose of the product and fluids according to local regulations.

Note: Sealey's policy is to continually improve products; data, specifications, and component parts may be altered without prior notice.

Important: No liability is accepted for incorrect use of this product.

Warranty: Guarantee is 36 months from purchase date, proof of which is required for any claim.

Register your purchase here: [link to registration page]

Sealey Ltd t/a Sealey Group, Kempson Way, Suffolk Business Park, Bury St Edmunds, Suffolk, IP32 7AR UK

Sealey (EU) Ltd t/a Sealey Group, Farney Street, Carrickmacross, Co. Monaghan, A81 PK68 Ireland

Tel: 01284 757500 - Email: sales@sealey.co.uk - Web: www.sealey.co.uk