hello and of course...help

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Hello all,  I have been doing lot of reading on this site and I am truly impressed with the knowledge and info available.  Good job every one.Well i guess i just wanted to say hello and ask the library of knowledge available here a question.I have a very, very old Weldanpower 150 that was riding around in the back of my service truck for the odd emergency on plow and construction equipment.  Great little machine, surprisingly capable.  Anyhow the Kohler 10 horse finally let go (some extra holes in crankcase) and I happen to have a 13 horse Honda sitting in the corner looking for a home.  Well I mated the two and now I have a problem, the recifier for the exciter keeps burning out.  I am aware that the flashing voltage of the Kohler was only 1.5-4 vdc but it was also available with a briggs or murphy at 12-14 volts.  As far as I can see on Lincoln's website the internal parts were all the same.  Any ideas??thanks Keith
Reply:Well I mated the two and now I have a problem, the recifier for the exciter keeps burning out. I am aware that the flashing voltage of the Kohler was only 1.5-4 vdc but it was also available with a briggs or murphy at 12-14 volts. As far as I can see on Lincoln's website the internal parts were all the same. Any ideas??
Reply:Thanks Sandy.  The rectifier used is a 34 A 800V bridge and it burns out only 1 of the diodes.  Engine rpm are both 3650 unloaded.  Also the resistance of the rotor is right on spec.  I'm just a little stumped as the thing worked really well prior to me messing with it.Keith
Reply:The rectifier used is a 34 A 800V bridge and it burns out only 1 of the diodes. Engine rpm are both 3650 unloaded. Also the resistance of the rotor is right on spec. I'm just a little stumped as the thing worked really well prior to me messing with it.
Reply:I have a portable (miller) 225 amp with a kohler engine on it, it has diferent rpm settings for weld and power, for weld the specs are 3000 rpm your engin sounds to be running about 20% higher rpm which might be effecting your welder (just a thought I dont know for sure) also if you solder a MOV or metal oxide varistor I would say 100 or 125 volts and 20 joules rated, one across each diode it should protect the diode from the voltage spikes cause when you break your ark from welding If it explodes like a firecracker use a higher voltage. These things are cheap enoughanother thought is your diode getting cooled good enough because over heating will kill them very fastLast edited by mattc; 03-19-2006 at 06:25 AM.Matt the Alaskan red neck
Reply:glad mattc is back wih us IF it Catches...Let it Burn
Reply:thanks, I never went too far just went under cover untill all the excitement blew overMatt the Alaskan red neck
Reply:Thanks for the suggestion.  I'l look into it.  The engine rpms are right on spec according to the manual.Keith