Announcement

Collapse
No announcement yet.

Miller legend low auxiliary power!!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Miller legend low auxiliary power!!

    I have a miller legend I picked up and seems to weld pretty well but the auxiliary power isnt putting out full 110 or 220. I already cleaned the commutator. Brushes moved freely and look almost new. Recepticles read 120 very briefly then drop to around 82-89 volts with fine adjustment turned all the way up on front of machine. Voltage will drop if fine adjustment is turned down but wont go up higher than previous. Can anyone help me out narrowing my problem down? Thanks in advance.

  • #2
    Will try to look at diagrams tomorrow.

    Comment


    • #3
      That would be great! Thanks!

      Comment


      • #4
        I assume you have downloaded the cog BBB Have you measured the voltage at the 100 hz outlet?
        Do you have a meter that will check freq at the 60 hz power outlet? Given your symptoms it doesn’t seem like the probable issue but it would be good to verify engine speed first. Should be adjusted for about 62.5 hz at the outlet, no load. However, I suspect a voltage regulator board problem, or perhaps an issue with the fine voltage control rheostat or associated wiring. Open the machine and do a good visual check of the control for burned spots, cracks, corrosion, etc. I would also check every connection on all the wires connecting that control to the regulator board.

        Comment


        • #5
          Wow not sure what is going on here but cog BBB souls say manual. In addition to the above, a very common problem is the connections on the adjustable resistors R2 and R4. R2 is a very likely suspect here. Check the connections at the end but especially at the adjustable band. Mark exactly where it is and then take it loose, clean its contact areas both on the band and the resistor and reinstall the band. At least a 50-50 chance that will solve your problem. You should be able to locate it using the manual; if not, come back for assistance. Good luck!

          Comment


          • #6
            I have printed off the manual for this machine or at least I believe. Everything looks the same.

            I'm not sure my tester does hrz but it put out the same low voltage on the the 100 hz side. Had the same low voltage at 1t terminal block. Nothing looks burnt but the r2 resistors are pretty rusty looking. I should just mark them and then clean them up then reassemble?

            Comment


            • #7
              Short of having a HZ meter , and since your checking low voltage anyway and to get to the point of where 41 was going initially ...try raising the rpm up a 100 rpm's +/- and see if your voltage follows along?

              Comment


              • #8
                Originally posted by Big88sub View Post
                I have printed off the manual for this machine or at least I believe. Everything looks the same.

                I'm not sure my tester does hrz but it put out the same low voltage on the the 100 hz side. Had the same low voltage at 1t terminal block. Nothing looks burnt but the r2 resistors are pretty rusty looking. I should just mark them and then clean them up then reassemble?
                Yes, mark where the band is on the resistor and clean it up well. I’m guessing that’s where your problem lies if it looks rusted up.

                You can buy a Kill-a-Watt meter (brand name) at Lowe’s, HD, or HF. It will measure freq as well as volts and Amos and is kind of nice to have to see how much power your household appliances are drawing also. Not very expensive.

                Tarry’s idea is good just to see if it changes anything.

                Comment


                • #9
                  I have a blue point multi meter so it probably does have hz. The rpms from my many years as a welder and mechanic sound dead on and also compared to my dads trailblazer with an onan but I'll mess with it tomorrow and check my meter. I'll keep yall posted and appreciate the input.

                  Comment


                  • #10
                    Ok so I cleaned resistors and their counterparts with no real change. Started looking around in my manual some more and found how to adjust r2 and r4. Started adjust and voltage came up some. About 121 steady on rc4. Checked my voltage on welding leads while I was at it and that was about 61. I adjusted r2 and r4 multiple times and after first adjustment havent been able to raise voltage anymore. I dont want to be adjusting them further and burn something else up. They are probably a good inch and a half from where they both started.

                    Comment


                    • #11
                      I'm thinking it may be the rheostat. How does one test that?
                      I did raise the rpms at least 100 aswell. It did seem to help a little. Any higher is beyond what it should be for sure.

                      Comment


                      • #12
                        OK. Getting an improvement by raising the RPM is a good sign. You really should get the RPM set accurately with a frequency meter sometime soon to keep troubleshooting. That is absolutely the first step to troubleshooting a voltage problem.

                        One of the most important things you can do with the rheostat is a really thorough visual inspection with a good light, and maybe even a magnifying glass. Look for cracks, discoloration, etc. I'd remove it from the machine for a really good look unless you can see it very clearly. Then, put an ohmmeter on it and turn it from one end to the other. I really like an old-fashioned analog meter for this, because you can see the needle jumping around if the wiper contact is intermittent. Some digital meters have an analog bar graph along the edge of the screen (usually on the bottom on mine) which is somewhat of a substitute, but not as good as an old analog meter. I sure do like my Simpson 260 meters! It should move smoothly from almost zero to whatever the rating of the part is--I didn't look it up again, but it's in your parts list--I think maybe 50 ohms? Check the manual.

                        Having to move the adjustment on R2 that far indicates that there is something else wrong. You are a wise man not wanting to get carried away with the adjustments. I'm guessing either a bad/corroded connection between the rehostat and the regulator board, or the wiring from the generator to the rheostat, or a component on the regulator board that has shifted in value.

                        Just on general principles, I would also check the exciter circuit bridge rectifier SR2 using the diode test function of your meter, just to make sure you aren't getting excessive forward voltage drop and thus limiting the voltage out of the bridge. If you need help with how to do that, just ask. And check all the connections to/from the bridge.

                        Comment


                        • #13
                          Found a writeup I did a while ago on diode bridge testing, so if you don't know how to do it, here it is.
                          Click image for larger version

Name:	DIODE BRIDGE TESTING.jpg
Views:	96
Size:	300.6 KB
ID:	611832
                          Attached Files

                          Comment


                          • #14
                            If a guy were to look for a used Simpson 260, any particular series over another?

                            No hijack intended.

                            Comment


                            • #15
                              I like the 260-6 and up. -6 Gets you to standard banana plugs for the leads, and batteries are a D cell and a 9-volt. Some real early ones had funky batteries. The -6 uses plain banana jacks in place of the old pin jacks / plugs that were easy to break off. The models with a P-suffix have a circuit breaker built in that protects the meter from stupid actions by the operator. :-). M-suffix is for the mirror scale to avoid parallax and allow very precise measurements, but if I need that precise of a measurement for everyday stuff I probably won’t be using a 260. The 260-7 series has male plugs for test leads recessed into the panel vice the female bananas in the -6. You can read all about al the models with pics and specs at simpson260.com.

                              Comment

                              Working...
                              X