Hello
As the title says, I have been reading the forum for a few years. I try to find answers from what others have asked, rather than ask repeat questions. Following an introduction to welding course at the local agricultural college, I bought a Murex Tradesmig 130 and an unbranded oil cooled arc welder. My wife and one of my sons also did a course at the college, and the three of us have been having fun with the welders.
The Murex has been losing power and recently stopped welding. The wire feed and gas valve still work and after a few hours with a multimeter, I have determined that there is power going everywhere it should right up until it comes out of the main transformer and into the AC side of the rectifier/diode bridge, but nothing coming out of the DC side. Based on this, I have decided to replace the diodes and the capacitors, and have now removed them from the welder.
The capacitors look as if they will be relatively easy to source. The old capacitors look like I remember capacitors looked like when I did O level Physics in the early 1970s. I think the key for these is the 10,000 mF and 63v and their size (so that I can screw new ones in without any modification. Interestingly, the existing capacitors seem to be dated March 1986 (and made in Hungary). If the replacements last as long as the originals, I will be well pleased.
However, I am not so sure about the diodes. They are rather different from what I was expecting. There appear to be 12 of them. Six marked EMW BYY 57 (in blue ink) and six marked EMW BYY 58 (in red ink) with the 57s on one aluminium plate and the 58s on the other. They seem to be pushed through the aluminium plates on one side, soldered to thinner plates on the other side with their wired joined.
If anyone has replaced diodes/rectifier/bridge on a Murex Tradesmig 130 and could tell me what (and where) to purchase, I would be very grateful.
Thank you
Jonathan E
As the title says, I have been reading the forum for a few years. I try to find answers from what others have asked, rather than ask repeat questions. Following an introduction to welding course at the local agricultural college, I bought a Murex Tradesmig 130 and an unbranded oil cooled arc welder. My wife and one of my sons also did a course at the college, and the three of us have been having fun with the welders.
The Murex has been losing power and recently stopped welding. The wire feed and gas valve still work and after a few hours with a multimeter, I have determined that there is power going everywhere it should right up until it comes out of the main transformer and into the AC side of the rectifier/diode bridge, but nothing coming out of the DC side. Based on this, I have decided to replace the diodes and the capacitors, and have now removed them from the welder.
The capacitors look as if they will be relatively easy to source. The old capacitors look like I remember capacitors looked like when I did O level Physics in the early 1970s. I think the key for these is the 10,000 mF and 63v and their size (so that I can screw new ones in without any modification. Interestingly, the existing capacitors seem to be dated March 1986 (and made in Hungary). If the replacements last as long as the originals, I will be well pleased.
However, I am not so sure about the diodes. They are rather different from what I was expecting. There appear to be 12 of them. Six marked EMW BYY 57 (in blue ink) and six marked EMW BYY 58 (in red ink) with the 57s on one aluminium plate and the 58s on the other. They seem to be pushed through the aluminium plates on one side, soldered to thinner plates on the other side with their wired joined.
If anyone has replaced diodes/rectifier/bridge on a Murex Tradesmig 130 and could tell me what (and where) to purchase, I would be very grateful.
Thank you
Jonathan E