Miller Bobcat 250 voltage drop

I bought a Miller Bobcat 250 at auction. The motor runs great but there is
a distinct drop in voltage. The generator only puts out about 103v and, hav
ing seen that, I haven't tried to weld with it yet. I live in a VERY rural
area with little or no access to certified Miller repair and am wondering i
f this is something that I can address myself. Where do I look for diagnost
ic info or parts? Anyone with any ideas of what I should be looking for wou
ld be greatly appreciated.
Reply to
koomie66
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Page 42/43 have a schematic of a Bobcat 250 NT.
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Page 50 here.
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My quick look, says they are the same.
I don't know how I would troubleshoot your symptom, so my first call would be to Miller.
Mikek
Reply to
amdx
Don't know if this applies to Miller, but in the Honda welder/generator that I have (EW170), there is a coil under the flywheel that provides excitation voltage to the generator field winding. If that voltage is low for some reason, the generator output voltage will drop. When I first got my unit running, with a Chonda motor replacement, I hooked up 12v dc in place of this voltage, since this engine didn't have the exciter coil installed. Very bright load test lights! Guess what...the Chonda has the mounting bosses for this little coil in place. Pretty good copy.
bill
Reply to
Bill Martin
Thanks Mike... Both web addresses were handy... I'll let you know how it goes... Thanks again!
Reply to
koomie66
Don't know yet if it will apply either... but I appreciate the post... Thanks!
Reply to
koomie66

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