Lincoln Electric Linc 635-SA is a conventional welding rectifier with a current up to 670 A, built on a transformer and meant for heavy industrial work. At a 35% duty cycle it gives 670 A, at 60% it gives 500 A, and in continuous work at 100% it holds 400 A. You weld with a covered electrode, run Lift TIG DC and gouge with air carbon, and an open circuit voltage of 78 V helps to strike the arc with difficult electrodes.
What this machine is for
This is a power source for heavy steel structures and for jobs where the electrode works for hours. A reserve of 670 A will pull electrodes over 6 mm in diameter, so you join large carbon plates and thicker quality sheet with it without dropping the parameters. A high open circuit voltage of 78 V gives a sure start and a steady arc also with basic and cellulose electrodes, which take weak power sources badly. The manufacturer aimed this model at heavy industry plants, refineries and shipyards, at companies putting up large steel structures and at workshops that routinely work with cellulose and basic electrodes. Each of these coatings behaves differently: rutile gives an easy start and a smooth face, basic gives less hydrogen in the weld and better impact strength in responsible joints, and cellulose gives deep penetration when welding pipes from the top down. A power source with such a reserve of current and such an open circuit voltage handles each of them without pushing the settings to the limit.
The second group of tasks is removing material. Once you connect a gouging torch with a compressed air nozzle and graphite electrodes, the machine cuts grooves, bevels hard edges and takes out old, corroded welds. Gouging eats current continuously, so what counts here is not so much the peak of 670 A as the 400 A at a 100% duty cycle, at which the operator works without breaks for cooling. The same reserve of current comes in useful when taking structures apart and when preparing grooves for multi layer welding. Gouging leaves a carburised surface behind, which has to be ground before welding, and it needs the station screened off, because the metal blown out flies far.
The model also handles Lift TIG DC, that is ignition by touching and lifting the tungsten electrode. For this mode you need a torch with a mechanical shielding gas valve. A contact start limits tungsten inclusions in the weld, so with this method you close the root run, and you add the filling layers with a covered electrode. Such a split of the work is met on pipes and tanks, where the root has to be clean and the rest of the joint has to be made fast.
Features and equipment
- Welding current up to 670 A with duty cycles of 670 A at 35%, 500 A at 60% and 400 A at 100%: you have a reserve for thick electrodes and for long continuous work.
- Open circuit voltage 78 V: the arc strikes surely also with basic and cellulose electrodes.
- Adjustable Hot Start: the circuit raises the current in the first milliseconds of contact between the electrode and the material, so the start of the pass does not come out cold, and a separate knob matches the starting peak to the material.
- Adjustable Arc Force: when the arc shortens and the voltage drops, the circuit adds a current impulse which tears off the drop and protects the electrode against sticking.
- Work with rutile, basic and cellulose electrodes: the power source controls the melting of each of these coatings.
- Lift TIG DC mode: ignition by touching and lifting the electrode, it needs a torch with a gas valve.
- Air carbon gouging: after you change the torch for a gouging one you remove material with compressed air and a graphite electrode.
- F.A.N. fan: the air flow starts only after a temperature threshold is passed, so the machine draws in less dust and fumes and takes less energy at rest.
- Backlit digital displays in the SA version: you see the real current while the arc burns, without reading a mechanical scale.
- Multi pin socket for a wired remote control module: you correct the current from the working position, which matters on multi run welds and when working inside tight tanks.
- Running gear with large wheels and a tube handle: you roll the rectifier across the hall despite a weight of 150 kg.
- Lifting eyes in the upper part of the frame: you lift the machine with a crane or a fork lift.
- Housing and insulation in class IP23 and H: the build is prepared for dust, damp and high temperatures in a hall.
- Transformer supply instead of an inverter: less electronics inside, so the build takes dust, damp and mechanical knocks on a building site and in a shipyard better.
- Panel with pictograms around the potentiometers: you read the settings without a manual, which shortens the training of a new operator.
- Work from a 230 V or a 400 V mains: you plug the same power source into two different installations, once the right fuse is chosen.
Technical data
| Brand | Lincoln Electric |
|---|---|
| Type | welding rectifier, manual control |
| Processes | MMA, Lift TIG DC, air carbon gouging |
| Supply | 230/400 V, 3 phases, 50 to 60 Hz |
| Maximum welding current | 670 A |
| Duty cycle 35% | 670 A |
| Duty cycle 60% | 500 A |
| Duty cycle 100% | 400 A |
| Open circuit voltage | 78 V |
| Mains fuse | 100 A at 230 V, 63 A at 400 V |
| Weight | 150 kg |
| Dimensions (h x w x d) | 670 x 580 x 700 mm |
| Protection and insulation class | IP23 / H |
What to watch out for
The machine works from a three phase 230 V or 400 V mains at a frequency of 50 to 60 Hz. The fuse is 100 A at 230 V and 63 A at 400 V, so before you buy check whether the switchboard and the cable cross section will carry that. It is the most common limit in smaller workshops, because the power source itself is ready for work and the installation is not. A transformer rectifier draws more from the mains than an inverter with a similar current, which shows in the bill in multi shift work.
A weight of 150 kg and dimensions of 670 x 580 x 700 mm mean transport on a pallet, not in a car boot. The machine has wheels and lifting eyes, so you roll it around the hall on your own, but for loading onto a vehicle you need a truck or a crane. For Lift TIG DC you need a torch with a gas valve, and for gouging a separate gouging torch, graphite electrodes and compressed air brought to the station, the description does not list any of these in the set. Class IP23 allows work under a roof, but not in the rain without cover. For the station pick welding cables with a cross section for a current of the order of 500 to 670 A, because a cable that is too thin heats up and eats the voltage that is then missing at the arc. When working with basic electrodes remember to dry the coating, otherwise moisture gets into the weld whatever the class of the power source.
How we sell used machines
This unit was checked in our service workshop in Krotoszyn with measurements to PN-EN 60974-4 and a load test. The price includes the first year of the basic service package: an inspection with cleaning of the machine and a validation measurement. Further years can be added. We ship across the European Union, collection in person by appointment.
