The Castolin CastoMig 500 DS is a stepped MIG/MAG power source built on a transformer in Fronius technology, the same layout as the Fronius VarioStar 500. You set the current from 25 to 500 A, the duty cycle is 500 A at 40% and 360 A at 100% at a temperature of 40 °C, and the supply is 3 x 400 V. The feeder is external and 4 roll, and the liquid cooler sits in the housing.
What this machine is for
This is a power source for heavy industry and continuous production. A reserve of 500 A at a 40% duty cycle lets you lay thick multi run welds, and 360 A with no time limit holds the pace through a whole shift. The transformer design with copper windings and a choke circuit takes dust, temperature swings and voltage drops on long supply lines in production halls.
The letters DS mean a separate wire feeder. The drive stands on its own and joins the power source with a cable package, so you take it into a vessel or onto a structure while the heavy power source stays at the station. The maker aimed this machine at steel structures in industrial and bridge building, at thick walled welding in machine and power industry, at the making of wagons and rolling stock, at overhauls of construction machines, among them excavator buckets and frames, at shipyards working on hull sections, at metal workshops that work for output and at stations for hard facing of large surfaces.
Voltage adjustment covers 30 steps, laid out as three ranges of ten settings, handled with a coarse and a fine switch. Such a dense grid is rare in transformer machines and it lets you match the arc to a thin section and to a thick plate. There is no synergic control here, so you match the wire feed speed to the chosen voltage step yourself, which gives full control and asks for practice.
MIG/MAG is welding with a wire fed in a continuous way, under a shielding gas. The wire melts in the arc and fills the groove at once, so you deposit a lot of weld metal per minute and you do not chip slag after every bead. In heavy structures the current reserve and the duty cycle count, because a multi run weld is made in several passes one after another. Here the machine gives 500 A at the peak and 360 A with no time limit, and at such a pace the bottleneck is usually the torch, not the power source.
A stepped power source works in a different way than an inverter. The voltage comes from taps on the transformer winding, so the setting is fixed and repeatable: a step once set gives the same parameter at every arc start, also after a week of standstill. The output choke smooths the current, not the electronics, so the arc keeps its character when the gas mixture changes and in pure CO2. The price for this simplicity is the lack of a dynamic change of inductance during welding, which inverter circuits do give.
Liquid cooling is integrated with the housing. A pump with a high head holds the flow also with a long cable package between the power source and the feeder, so the torch works at 500 A with no breaks to cool the accessories, and gas nozzles and contact tips live longer.
Features and equipment
- Copper main transformer: windings of electrolytic copper carry current and heat well, so the arc is soft and stable even on a dirty surface, and the power source takes thermal overloads in multi shift work.
- Voltage adjustment in 30 steps, in a three times ten layout: a coarse and a fine switch give exact tuning of the arc to the material thickness and hold down spatter.
- External wire feeder with a 4 roll drive: four toothed rollers guide the wire without deforming it, which with long torches protects against porosity and an unstable arc.
- Integrated liquid cooler with a high head pump: a steady coolant flow also with a long cable package, so the torch takes a current of 500 A.
- 2T and 4T modes: two stroke for short assembly welds, four stroke for long beads without holding the trigger, which spares the hand on welds several metres long.
- Burn back time adjustment on a potentiometer in the feeder: it protects the wire against sticking to the pool and to the contact tip and sorts out the start of the next arc.
- Resistance to voltage drops: the transformer design on a copper winding works in a steady way also on long supply lines in industrial halls.
- Reinforced feeder housing: it takes knocks and workshop conditions, and the spool is shielded from dust.
- Large output choke: it smooths the current after rectification, damps voltage ripple and holds down spatter, also when you weld in pure CO2.
- Simple service handling: a classic build means less electronics to diagnose, and a repair comes down to the switches, the choke, the rectifier and the transformer windings.
Technical data
| Brand | Castolin |
|---|---|
| Type | stepped MIG/MAG power source on a transformer, separate feeder |
| Maximum welding current | 500 A |
| Duty cycle 40% at 40 °C | 500 A |
| Duty cycle 100% at 40 °C | 360 A |
| Current adjustment range | from 25 to 500 A |
| Number of voltage steps | 30, in a three times ten layout |
| Supply | 3 x 400 V |
| Cooling | liquid, integrated system |
| Wire feeder | external, 4 roll |
| Design equivalent | Fronius VarioStar 500 |
What to watch out for
The machine needs a 3 x 400 V connection. A 40% duty cycle at 500 A gives four minutes of welding in a ten minute window, work with no limit starts at 360 A, and the values are given for an ambient temperature of 40 °C. The adjustment is stepped, so you will not change the voltage while the arc burns, you pick the step before the bead.
The liquid cooler is built in, so the torch has to be liquid cooled. Watch the fluid level and the flow through the pump inlet filter, and change the fluid made for welding coolers once a year, so that no deposit builds up in the circuit. Lead the cable package between the power source and the feeder with the bending radius kept, because the work of the feeder motor and even wire feeding depend on it.
There is no synergic control here, you set the wire speed and the voltage step yourself, so a new operator needs a few tries on scrap. You match the rollers, the liner and the contact tip to the diameter and the type of wire. A transformer with copper windings gives a high total weight, so you need a trolley to move the set, and the data sheet gives neither the weight nor the dimensions, so ask before transport.
This unit is sold
This machine has already gone to a customer. Similar units are listed below, and if you want the same model, leave your contact details in the form and we will let you know when the next one arrives.