Powerwave 455

[Rilniceguy]

Yes i tied all three together

[jjohn76]

It depends on if your machine has the 208/230/460 input, or just the 230/460 input. Did you already modify to the wye output - basically adding a single copper bus across all three outputs on your contactor? If you're not planning to run over 25V output and it runs how you like, it's probably not worth changing.

[Rilniceguy]

Haven’t checked forum in a while. Sorry and thanks for the link, it works. As u know i have the whiteface models, are u saying i could try your mod? Btw i only need up to1/4” welds.

[jjohn76]

I used to have video capture of the panel from welding hot, but could only find this picture. It's the screen capture from the video, and doesn't show the full voltage (voltage still climbing), but 300+ amps with about 1" of stickout...

[jjohn76]

Hopefully the link works. I couldn't post the picture for some reason. The black face Millers had the 200/230/460 options, so when I wired it the way it is in the picture (note the green jumpers), the designed voltage for those primary windings matched 230VAC - it gave me 24VAC and 120VAC (maybe 115VAC, can't remember) on the output, which was closer than you could get on the older 230/460 machines. Some folks didn't change the output (shown in the picture), which is worked for over 250 amps, but I ended up using a wye (connect one side of each secondary together, the other side stayed connected to the contactor), which gave 70% boost in voltage and let me run the machine up to 32+V and 300+ amps for FCAW-G.

https://www.dropbox.com/s/wwx7nyx8rxdrgwy/CP-300%20H-K%20Wiring.jpg?dl=0

[Rilniceguy]

You mean you no longer had the three legs coming out of the output side of the contactor tied together?

[jjohn76]

I can't remember what I added, I want to say pairs of 65uF, but it's been a few years. I had the newer boxes (black face), which let me keep the accessory outputs at 24VAC and 120VAC. I had them in the existing delta on the output for a little while, but found they ran better with the wye output.

[Rilniceguy]

(45uf/leg)

[Rilniceguy]

Oh sorry jjohn76 yes those caps on top are the “phase” caps. ( i have two cp300’s)on that machine i put them on top. Btw 45uf seemed to work the best and with no hum. How about yours?

[jjohn76]

I don't know, but all of the ones I had I converted back because someone with three phase wanted to run them...

[Rilniceguy]

Wow. Amazing. I wonder, how much better do they run on three phase?

[jjohn76]

I came across them all the time when I lived in Washington. I remember running a CP-300 converted with just the phase caps and output wye with FCAW-G. The first time I tested it was on a 30 amp breaker, and it was pushing over 300 amps at what should have been 34V. My gloves gave out from the heat before the breaker did.

[Rilniceguy]

These old Millers really lay down some mean beads. Its seems like i can run a fillet weld on 1/4” at 200 amps in spray transfer easier than i can run a test bead on 1/8” at 140 amps!

[Rilniceguy]

Up here in metro detroit those old millers and aircos can be found for $100,$200 here and there

[Rilniceguy]

Well no need for adding a reactor. The cp300’s already have one from the factory. But i did do Henions mod on my Airco shown above, the one that uses the slope coils as reactors and it works great. I tried making my own reactor like he did and i think the slope coils made for a flatter, better bead. That along with 100,000+uf transformes that machine.