How to determine if welder is bad.

[lhearold]

I have recently gotten a lincoln weld-pak 175 HD mig welder. It worked fine for a couple of weeks, now however, I need to keep the wire speed way fast even on the lowest amp settings to keep form burning thru sheet metal. It appears as though the amperage is set too high. Is there a way to check the different amperage settings without taking the machine to a service center? THe nearest one is approx 25 miles (40km) from me and if possible I would rather be able to have a definate idea what the problem is before I go deal with the service people. Any one have any suggestions?

Thanks,

Larry

 

[shenion]

The power setting on the welder select different taps on the transformer. Either it works as designed or it does nothing.

Have you changed to a different wire? Different gas?

Since the minimum setting is about 30A, you would want to use 0.6mm wire to reduce the current.

Maybe you technique has changed. You can reduce the current by increasing the gap between the gun and work, angling the gun to 45 deg and to a small extent by increasing the gas flow.

 

[lhearold]

Lincoln doesn't say what amperages for what settings. It has settings of A thru D with A being the lowest and D being highest. The wire speed settings are 1 thru 10 with 1 being the slowest. According to their settings, to weld 16 gage sheetmetal, the settings should be A-3 using .006mm wire nd a gas setting of 15 lph (80/20 mix). Started out that way and it worked fine for about 4 days (I'm replacing panels on a car). No problems keeping the proper distance on contact tip, etc. Next day it would burn the wire off right up to the tip at that wire speed and burn thru the panel, just as if the amperage was too high! Had to increase wire speed with all other settings being the same. Right now, in order to keep from burning thru, I'm running the wire speed at around 8 and keeping the tip about 1/2 inch to 3/4 inch away from the surface. I'm using the Lincoln wire that I get thru the welding supply house here. Just think its strange that it should do so well then all of a sudden change.

Larry

 

[shenion]

The only thing I could think of is a short in the primary windings. That could raise the output voltage.

Could possibly be a bad switch. Does the A-B-C-D switch still move like it used to do, with no sloppiness, binding and still has definite detents where the positions are?

 

[solenoid]

wire feeding
sometimes when their is a restriction on feeding the wire can cause this effect.
some clues for you
wire twisted on the reel not coming off layer by layer, wire reel hub tension too tight, tension arm on wire feed too tight. liner full of copper dust etc, kinked liner and torch,tip worn.wire speed too low in relation to volts setting.