Welder Problem

[DRussell]

I have a Century 295 AC/DC welder with a high frequency arc stabilizer. A couple days ago I was welding on DCEN and it quit. I could not get an arc to start at all. There is nothing on DC. The high frequency arc stabilizer still worked. I switched over to AC and it would work just fine.

I tried it again today, still nothing on DC. AC works fine. The high frequency stabilizer works fine.

I took the top off of the welder today and looked at the wires inside. I don't see any wires burned through or even where it looks like they got hot.

Any ideas what is wrong with it?

 

[old]

I'd bet on one of the diodes has gone bad and is now an open both ways so no current

 

[DRussell]

Any idea where a new diode can be purchased?

This post was edited by DRussell on 12/18/2021 at 09:23 am.

 

[old]

If you have a welding supply store around they should be able to give you a place to get them. Many welding supply places also repair welders

 

[DRussell]

Thanks, I'll check with some next week.

 

[Janicholson]

I'll add to old's idea with the need to disconnect the components when checking them as they are often in a circuit that will chnge the reading. Search for a circuit diagram and trace electricity before taking things apart. Jim

 

[wore out]

(quoted from post at 09:39:10 12/18/21) I have a Century 295 AC/DC welder with a high frequency arc stabilizer. A couple days ago I was welding on DCEN and it quit. I could not get an arc to start at all. There is nothing on DC. The high frequency arc stabilizer still worked. I switched over to AC and it would work just fine.

I tried it again today, still nothing on DC. AC works fine. The high frequency stabilizer works fine.

I took the top off of the welder today and looked at the wires inside. I don't see any wires burned through or even where it looks like they got hot.

Any ideas what is wrong with it?

If you are able to determine a diode(s) is "bad", examine it closed (magnifying glass) for identifying numbers.

If you find some, GOOGLE them and see what comes up.

Likely, you can find them for a FRACTION of what they'd be from an "official source".

Of course, they may be unmarked to prevent just such a savings!

Just be careful, there's LOTS of voltage AND current inside a welder! Test diodes with the welder UNPLUGGED and the at least one "side" of the diode disconnected.

 

[guido]

DRussel,

Sometimes the diodes will take out some resistors too. It may not be in your case. 10 to 20 0hms is usually the resistors value. Just another component to check.

You will need to take one leg out of the circuit, (isolate it), this will insure no circuit interference,

Guido.

 

[old]

I still remember one of the guys I worked with at Tracker Marine and how he got him self zapped big time. We both work in the maintenance dept. One of the welders stop working as it should. He thought he had the breaker for it tripped but he tripped the wrong one ad he didn't check for voltage before putting his hand in it. He got across 440 3 phase and he was never right after that. Messed him up big time both physical and mental