Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums
 
Miller Welding Discussion Forums - Powered by vBulletin

Results 1 to 10 of 13

Hybrid View

  1. #1
    Join Date
    Oct 2013
    Posts
    5

    Default MM 250X voltage questions

    Hi, all,
    I've been a long time reader of this forum, but never had a need to sign in and post before. Tons of great info here! I am learning to weld (self-taught), and purchased a used 250X. Last night, I noticed the volt meter fluctuating, which I haven't noticed before (at least not to this extent). I was welding 1/8 steel, with the volts set to 17.3. When I released the trigger, the meter was reading 16.4, but after a few seconds reset to 17.3.
    This morning, I went back out to fool around some more with it. While welding, the voltage drops, then fluctuates (bounces!) between 16.2 and 17.3, rarely getting over 17.0. When I release the trigger, it usually stops at 16.4, then, four seconds later, bounces back to 17.3. I then thought to check the voltage without load: I turned the gas off, opened the drive wheels, and pulled the trigger. The voltage read 17.3 for 2 seconds, then dropped to 17.0 and held. When the trigger was released, four seconds later, the voltage went back up to 17.3. I pulled the cover off of my sub-panel to make sure the input voltage wasn't dropping, but it stays at 240V.
    I assume this isn't normal, that the voltage should remain fairly constant. Can someone point me in a direction to problem and cure? Thanks in advance!

  2. #2
    Join Date
    Aug 2004
    Location
    Milan Michigan
    Posts
    1,633

    Default

    Thats normal that they jump around a little, Maybe a question for cruizer but I'm pretty sure why it bounces around is becuse of your arc length.

    Unless your experiencing a problem dont worry about it.

  3. #3
    Join Date
    Oct 2013
    Posts
    5

    Default

    Thanks for the reply, Portable Welder. I wondered if that might be the case... that the bouncing voltage was normal. The thought ran through my mind as I watched it that if I had a machine without a digital readout on it, I wouldn't know that the voltage was fluctuating!

  4. #4
    Join Date
    Sep 2005
    Posts
    831

    Default

    Voltage will vary a little with changes in stick out length.

    I am not familiar with the 250X, I use to own a 251. Anyway, if you have the wire speed set a little to high, the power source may not be able to maintain your preset voltage.

  5. #5
    Join Date
    Jun 2009
    Location
    greenfield new hampshire
    Posts
    858

    Default

    correct me if i am wrong, the mm250 was millers new welder when they retired the mm200, the 250 was millers first digital mig at that time, and they carry a slightly bad reputation for the way they weld. i would not worry at the least for the variation in voltage. line voltage changes all the time, which will show up on the dial. are you using a 6 or 8 wire with a 50 amp plug. a lite wire will increase ressistance and lower the voltage

  6. #6
    Join Date
    Oct 2004
    Location
    Edmonton, Alberta
    Posts
    7,233

    Default

    Well yes, unless your a robot, or a hudderite, the fluctuation is completely normal as the internal computer is watching your stickout and increasing or increasing the voltage to maintain the weld

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Welding Projects

Special Offers: See the latest Miller deals and promotions.