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Powcon welder experience

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  • #46
    I was just looking at a TA400GMS. They just cost far more than the powcons do. I also like the ruggedized case. Maybe I can find a broken one for almost nothing and you can have a ball breathing life back into it!


    • #47
      Really? Working TA 400GMS units cost between $300 and $500 around me. Working POWCONs are advertised anywhere between $150 and $1000 around me. It might be the shipbuilding industry up here though.


      • #48
        The one I was looking at was on eBay and now I can’t find the listing for it. Figures.


        • #49
          So the Power Wave 355 (like the Invertec V350 Pro except needs a dedicated feeder to operate) is back running after all boards checked out and it needed all FOUR(!!!) new bus capacitors. They're 4200uF each! They would be nothing special (read much cheaper alternatives available) if it wasn't for the higher current M6 threaded connectors with a much larger contact surface. Rather than run the risk, I just put the Lincoln ones in...

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          Below is a picture of why Lincoln doesn't need to derate on single phase. They put in more capacitors. The current ripple handling for capacitors is largely related to the size of the can. Left to right is the quad set in the Lincoln, the XMT 304's pair (the XMT 350 has slightly smaller 1800uF capacitors but gets away with it because of a PFC boost input circuit that limits ripple-they're in series too, because the XMT350 boosts the voltage bus to 800+VDC), the older XMT 304/Dynasty DX pair, the pair from a POWCON, and the six pack of smaller capacitors that go into the Thermal Arc 300TSW Pro Wave (the TA 400GMS and LM300 use an eight pack of these). The Millers have a thread connection on the back end, which adds about an inch of height. The white cans are the same size as the red ones, and the blue cans are only an inch taller but smaller in diameter.

          Click image for larger version  Name:	IMG_20200112_132316175.jpg Views:	7 Size:	3.00 MB ID:	606074

          Putting several smaller capacitors in parallel is a very good way to go and usually handles the ripple current a bit better. It just takes more effort (and usually copper) to make sure they share the load well. The thing I don't like about the Thermal Arc design is those are all snap in/soldered and a bit more difficult to replace when the time comes (ccawg posted on here to replace capacitors every 10-15 years). This is how they're mounted on a TA LM300, which is the same board as the 400GMS. They're soldered directly to the board.

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          They are only a two pin snap in capacitor, so easier than what's on a Dynasty 200, but still prone to pulling the eyelet when removing them. They also cause more damage to the board when they fail. Here's what the TA 300TSW main board looked like after to a failed capacitor (first one I have seen on a dozen TAs though). The fourth one from the left burned the PCB copper (these older ones didn't have the relief on top to fail outward). You can see on the first and third capacitors where I lifted the eyelet, so I cleaned away the solder mask and installed/soldered a new rivet eyelet. I have cut copper foil to replace the burnt PCB after cleaning out the charred area and filling the void back in with hi temp epoxy. It should be back up and running soon.

          Click image for larger version  Name:	IMG_20200101_183138761.jpg Views:	9 Size:	2.03 MB ID:	606076
          Last edited by jjohn76; 01-13-2020, 06:43 AM.


          • #50
            High tech man. Good info.