Need to rewire AC output on a Miller Big 40

[serfur1]

I have a DC weld Miller Big 40 (70's era), but it does provide 120v AC. There used to be an optional 7500W kit for AC output which I'm assuming was just a junction box for splicing a new wire, probably a fuse and directions of where to hook up the wiring to get 7.5KW out of the generator instead of the standard 3KW. Does anyone know anything about this or where on the generator to hook up to? I've had the cover off and the exising 120V circuit is just taped into the winding on the bottom. I was halfway expecting to see taps to hook to.

[MAC702]

This would best be asked to Miller's Tech Support. Call 1-800-4-A-MILLER. They'll let you know what you can and can't do.

Do you have your owner's manual? Get it here: http://www.millerwelds.com/service/ownersmanuals.php

[propanehotrod]

I have a 1990-ish big40 g and want to do the same thing, There is a schematic on one panel that shows the generator putting out 12kw in 3 phase and 8kw in single phase. and it says optional. I want to know if its just a matter of hooking up leads in the right place or if it was a whole different generator that was "optional" . Miller wont talk to me because there are no #'s anywhere on the machine. Sombody lost/ took off the serial numbers on the engine and the welder before I got it. I'd appreciate some help figuring out the year of the welder and if the auxiliary power "option" is do-able.

[LawsonWeldingLLC]

lol and here i was hoping to see someone asking how to rewire to use ac output on the welder
http://www.millerwelds.com/om/o450n_mil.pdf page 16

[LawsonWeldingLLC]

lol and here i was hoping to see someone asking how to rewire to use ac output on the welder
http://www.millerwelds.com/om/o450n_mil.pdf page 16

[LawsonWeldingLLC]

and here i was hopin someone was talkin about pulling ac weld output from the welder lol
http://www.millerwelds.com/om/o450n_mil.pdf
page 16

[propanehotrod]

Thats what Im talkin about but my welder dosent have the junction box. Can I still do it by adding a box and if so where do i tap in to the generator?

[propanehotrod]

Here are some pics of my big40 g when I had it apart to replace radiator and water pump
61136

61138

61139

61140

Hoping somone can tell me the year too.

[propanehotrod]

Here is the schematic that makes me think the AC rewire is possible
The Delta (triangle) in the upper right says optional AC

[duaneb55]

Unfortunately it's not a simple matter of rewiring or hooking a couple wires up. The optional 12.5/8.5kVA is a completely different stator than the standard unit. That's why 12KW Auxiliary Power Kit was listed as a "factory only" option. The only reconnect capabilities was to convert from a 12KW 3-phase output capacity to 9KW 1-phase.

The reconnect capabilities of the standard stator is to provide a 240V outlet rather than 120V only.

[propanehotrod]

So you'r sayin im stuck with 3kw generator output?

[Broccoli1]

So you'r sayin im stuck with 3kw generator output?

Yup:cool:

[LawsonWeldingLLC]

Hutch aint to far away ya wanna get rid of it ? lol

[propanehotrod]

Id trade for a 3 phase bobcat! :D