Power source and wire feeder or integrated MIG welder?

[Goober]

Question for those more experienced than I in welding - I picked up a good condition CP252TS for cheap a few weeks ago and am wondering if I should get a wire feeder for it and sell my 250MP MIG machine or if I should sell the CP252 and keep my 250MP. All my welding I do is in the shop, so portability isn't an issue, and I have 3 phase (from a large rotary phase converter). I am pretty happy with the 250MP but I see that the CP252 has 100% duty cycle at 250 amps vs 60% for the 250MP. I have some intermittent work hardfacing heavy machinery where 100% duty would be nice, but most of my stuff is medium sized fabrication on steel. Are there relative advantages of the power source + feeder over the integrated machine? Does one weld better than the other? (since I don't have a wire feeder at the moment I can't really evaluate the CP252TS head to head against the 250MP). Does the CP252 use less or more electricity than the 250MP? I was thinking that keeping the CP252, selling the 250MP and replacing it with a 211 set up for small diameter wire would leave me with an ideal all round setup (I already have dedicated red-colored stick machine and a Dynasty 200DX - so my bases are covered). If I do get a wire feeder which one is a good match for the CP252? I see a lot of them paired with 22A or 24A - is that a good choice? what's the collective wisdom say?

[cruizer]

Yeah, no the 3 phase rotary wont work well with that machine. Nuke the board is short order
.

[buffumjr]

This may answer your questions.

http://shdesigns.org/Welding/CP-250/cp-250.shtml

Lots to read, but lots of info.

[Goober]

I'm not interested in converting the CP252 to single phase, seeing as it's a straight inductive load with no sensitive electronics I'm comfortable running it from a 20hp rotary phase converter. Looking more for feedback on the relative merits of an industrial power supply + wirefeeder vs. an all-in-one MIG machine.

[buffumjr]

I'm not interested in converting the CP252 to single phase, seeing as it's a straight inductive load with no sensitive electronics I'm comfortable running it from a 20hp rotary phase converter. Looking more for feedback on the relative merits of an industrial power supply + wirefeeder vs. an all-in-one MIG machine.

OK, Going back to your original post, you are looking for 100% duty cycle MIG for intermittent "big jobs" that require it. If you have bumped up against the 60% duty cycle of your current machine, and it is an annoyance, then the industrial strength machine is a no-brainer. If the 60% duty cycle doesn't really interfere with your work flow, then "go with what you know.". The one warning is what we hobbyists find so annoying. "You're gonna need this." and "You're gonna need that." and you look up toward the end of the process, and you've laid out hundreds, maybe thousands. So, it boils down to just how annoying is a 60% duty cycle. Answering that one question should answer your original question.

A 20 hp phase converter costs about $3,000 (Grizzly) and weighs about 300 lbs. Gadfry! Then, there's Larry the Electrician to wire it up. Then, there's the location of the converter, takes floor space, maybe the size of a small closet. Then, there's whether you need the welder mobile or static. Why not buy a brand new red or blue industrial strength that can be wired to single phase? Same money, less hassle. Warranty. Support.

[Goober]

OK, Going back to your original post, you are looking for 100% duty cycle MIG for intermittent "big jobs" that require it. If you have bumped up against the 60% duty cycle of your current machine, and it is an annoyance, then the industrial strength machine is a no-brainer. If the 60% duty cycle doesn't really interfere with your work flow, then "go with what you know.". The one warning is what we hobbyists find so annoying. "You're gonna need this." and "You're gonna need that." and you look up toward the end of the process, and you've laid out hundreds, maybe thousands. So, it boils down to just how annoying is a 60% duty cycle. Answering that one question should answer your original question.

A 20 hp phase converter costs about $3,000 (Grizzly) and weighs about 300 lbs. Gadfry! Then, there's Larry the Electrician to wire it up. Then, there's the location of the converter, takes floor space, maybe the size of a small closet. Then, there's whether you need the welder mobile or static. Why not buy a brand new red or blue industrial strength that can be wired to single phase? Same money, less hassle. Warranty. Support.

Definitely - if I had to buy and install a 20hp rotary phase converter to use this CP252TS machine it would be a no-brainer - I would sell it. Luckily I already have the 20hp rotary installed and working to power the mill, surface grinder, pedestal grinders, lathes etc.., it's capacitor tuned for near-perfect leg voltages when running a 5hp load (the big lathe), so it'll be a bit off when running the CP252TS at 250A output, but not too bad, I could add a few more capacitors and switch them into the circuit when I will be running the CP252TS full bore. As it is, all I would have to buy and setup in order to switch from the 250MP to the CP252TS is a wire feeder - I have 3 bernard Q-guns setup with sleeves for small, medium and large wire - standard miller ends that fit the 250MP. The hassle factor of having to stop every 10 minutes doing dozer blades and backhoe buckets is what prompted me to consider this change to the CP252TS. Also, the 250MP can just barely do spray arc with .045 - I'm pretty sure the CP252TS would handle spray arc no problems, but can't test it without a wire feeder. Maybe what I need to do is find a place to rent a wire feeder and try this puppy out.

[Broccoli1]

As for power use I imagine they are about the same since they are both transformer machines.

With each one set to respective welding amps- the 3-phase machine will always be more efficient but I doubt so much that a one man shop one would notice it the electric bill.

If you were switching to a new inverter machine you would see a noticeable power use difference.

[buffumjr]

Congrats! Looks like you have your question answered, and a plan in place. Rent before buy is brilliant! Dozer blades! Wow. But I thought that kind of work was stick territory.