Miller CP300 vs CP302 what are the differences?

[Razorhunter]

Can anyone tell me the differences between these two machines here, even if very minor?

Also, are there any other Miller transformer based MIGs out there that are either still being made, or that are newer than the old CP's? I'm wanting to find a good transformer machine with 100% duty cycle, and I'd like to know any other models to look out for. (Nothing decades old, more recent preferably)
Thanks for any help guys.

[digger doug]

IIRC deltaweld 450.
Could be they bumped the number up to 452

[weldor2005]

They also have a DW 302. Do your research, I've heard from Miller that the Delta weld line is making the switch to transitors shortly.


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[GWIZ]

Without specific serial numbers it maybe hard to know for sure.

First they both appear to be Three phase machines.

Manuals are not always accurate as to what supply voltages are required, you will need to double check the welders data plate, you do not want to get stuck with a 520 volt Only machine.

Both
Appear to have carbon brushes that span across the transformer winding's for voltage control.
Can be an issue on a well used machine as to wear parts along with the surface of the transformer.


**********

CP-300

Net weight 287 lb.

Looks like the Inductance Stabilizer can be selected without opening the unit up.
two positions.


****************
CP-302

323 lb.

Just a note from A manual
Constant speed wire feeders are used with constant voltage (CV) power sources.

Looks like the 302 has an internal Inductance Selection transformer, will need to open up the machine to select taps.
two position tap.

The 302 replaced three diodes with three SCR's.
Best I can tell or Guess, the 300 uses a contactor to kill welding power, so you hear a big click and relays contacts wear out.
I don't see a contactor in the 302 so I assume they incorporated the use of SCR's to switch off welding power in place of the contactor.

[Razorhunter]

GWIZ,
Thank you Sir. THAT is exactly what I was looking for.

[bunkclimber]

I think Miller has gone all inverter now,even with the bigger power supplies.I only see the CP302 in the lineup now.The older CP250s and CP300s are transformer based 3phase CV MIG weld power sources unkillable under normal conditions..a few recipes for single phase conversion are out there for them on the 'net to try as well..after killing my second XMT inverter in a row($1500 in just parts to repair) I went with a CP250TS for my MIG source..it's just not as portable as the XMT. The CP252 and CP302 versions add a reactor on the output side..any of them is a safe bet for longevity..

Originally Posted by Razorhunter

Also, are there any other Miller transformer based MIGs out there that are either still being made, or that are newer than the old CP's? I'm wanting to find a good transformer machine with 100% duty cycle

[monckywrench]

Miller manual downloads:

https://www.millerwelds.com/support/manuals-and-parts

[Razorhunter]

Bunkclimber, thanks for the reply Sir. Hey can any of you guys tell me about this Miller CP200? Its listed as an "arc welder" and it looks unlike any other I've ever seen. I believe its just an older model from a different era, as ALL of the CP200's were indeed MIG welders correct? (as opposed to "arc" welders) ??? Am I correct?

[Razorhunter]

I'd rather have a CP300 or 302, but at that price I may grab it. Its out of state, but not too far off my route I'll already be taking anyway. I just don't know about the quality of that "Oxomatic" wire feeder thats shown though...?

[Norcal]

Originally Posted by Razorhunter

I'd rather have a CP300 or 302, but at that price I may grab it. Its out of state, but not too far off my route I'll already be taking anyway. I just don't know about the quality of that "Oxomatic" wire feeder thats shown though...?

But what is the voltage/phase? Seeing the pin & sleeve plug on the machine could mean 230/460V 3Ø, but if you have 240V 3Ø there are lots of options, run of the mill 120/240V 1Ø limits options. But I did not look up the manual for that machine to see what supply voltages Miller offered either.