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Old 10-21-2018, 03:55 PM
Razorhunter Razorhunter is offline
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Default Miller CP300 vs CP302 what are the differences?

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.
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Old 10-21-2018, 05:56 PM
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digger doug digger doug is offline
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IIRC deltaweld 450.
Could be they bumped the number up to 452
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Old 10-21-2018, 08:47 PM
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weldor2005 weldor2005 is offline
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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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Old 10-23-2018, 12:51 AM
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GWIZ GWIZ is offline
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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.

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.



Net weight 287 lb.

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


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.
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Old 10-23-2018, 12:00 PM
Razorhunter Razorhunter is offline
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Thank you Sir. THAT is exactly what I was looking for.
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