oscillating volts and amps on XMT 304

Date 07-12-2008 17:10

What is wrong? I finally hooked up my Miller XMT 304 that I bought used and the volts and amps oscillate. The power cord is three phase but the plug in (house dryer) is one phase. So I tucked back the red wire and hooked it up as 1 phase for the three prone plug that I need. I'm running the black wire to the top (or v shaped prong) and the white and green to the other straight prongs. Whats the deal? Is it my welder or did I screw something up?

By aevald

Date 07-12-2008 20:42

Hello MetalFinagler, you really need to check on the proper orientation of the ground lug on the plug you are using to be sure that you have the ground wire(green) hooked up to the appropriate blade, I don't believe you do from your description. You have tucked back the correct wire for single phase use, however you may have hooked up one leg of the 220 to the ground wire to your machine which could pose a severe shock hazard to you and possibly damage your machine. Green is ground, black is a 110volt leg in 220volt single-phase operation and white is another 110volt leg in 220volt single-phase operation. BE VERY SURE of the proper connections on the plug that you are using and verify with a volt meter before trying to use your machine further. If possible get ahold of an electrician or other qualified electrical technician to help you with properly hooking up your machine. Best regards, Allan

By MetalFinagler (*)

Date 07-12-2008 21:09

um, yeah I definatly have it hooked up wrong then. I only had it plugged in for about a minute so hopefully nothing got messed up. Maybe I should read directions before I do anything like this from now on. I was assuming black was ground as it is for audio and jumper cables. Thanks Allan.

By MetalFinagler (*)

Date 07-12-2008 21:28

Well that was the problem. I guess its my one freebe. Thanks again Allan

By aevald

Date 07-12-2008 21:37

Hello again MetalFinagler, glad to hear that you got it figured out. You may want to go to www.millerwelds.com and see about downloading the owners/operation manual for your powersource and feeder, I believe they have it available in PDF. form for free. Good luck and happy welding! Best regards, Allan

By sbcmweb (****)

Date 07-13-2008 00:06

Black will be ground on a DC system generally. The input power is AC. Green is always ground on the Miller Inverters corded from the factory. I see you already have it figured out. Luckily, you only had 115 going in. On the older jumper link inverters, if you go hi voltage input with low voltage jumpered, you just fried the SCR & usually both IGBT modules. Bad news. No biggie here. Something you can keep in mind for the future. I just cut the red cord off on mine, since I knew I would never be running it off 3 phase. Good luck. S.W.

By fbrieden (***)

Date 07-13-2008 03:51

Drop the red and use the black, white, and green.