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Eurybates

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  1. Liked to come here from time to time. Looks like there are no posts for 2019 ...or I just can't find them!. Funny enough, I can still login. Makes me wonder if Mark is OK. What happened?. The combined knowledge of this forum was fantastic. Oh well. over and out
  2. OK. Figured it out. Was not drawing it correctly and now it's embarrassingly obvious. If anybody stumbles onto this post and wants the complete details for constant torque dahlander (including easy to understand magnetic pole diagram) just reply to this post and I can email. Cheers
  3. Hi all. Hoping that somebody has had this issue and could maybe shed some light. I recently detailed a motor unaware that it was a 2 speed. It appeared to be a two pole two parallel path connection with six leads out. I had a look at the supplied 3 position barrel switch to discover it was not a reversing switch but a pole changer. The motor is 36 slot with six groups consisting of six coils each with a pitch of 1 – 10 constant (or) 1-5-7-9-11-13 concentric / 0.5mm copper wire and 48 turns (one in hand). I should have noticed it was under pitch while winding. What is worse, I then decided to double cross sectional area halve the turns and turn it into a series connection.. which would have worked had it been a parallel to begin with!. I thought at first that it must be a two star type connection which I have done many of before, however each lead has two circuits and there was no internal star or any other internal connection All 12 conductors are accounted for. Normally the 2 wye are supplied by the consequent connection on each phase and the other open ends are the second star point made externally by links (or a switch) for the 2 pole and then the external star is supply for the 4 pole with the consequent connections left open. After some research I came across the dahlander parallel wye or series delta. But here is my issue I can not draw it out with the magnetic north and south poles to make sense on paper as a line type diagram. Normally my rule is if I can draw it then it will work. Would anybody be able to help me with this? Just with the North in and South out diagram when series delta or parallel wye. It would be a load off my mind and much appreciated.
  4. Really, If you don't agree with Mark, then the best thing to do is to find the inter-cable-phase-adapter, Make sure the termination is nice and tight. Swing on it a few times and go research the power triangle for a while before dedicating your life to three phase theory. If this does not work, then get a job talking as much *beep* your body can handle without imploding into approx. 10 micro-farads. Best of luck PS.. If this post is not deleted, I will assume that LMP forum is dead and gone. ) .. Was good talking
  5. 2014 now. Have not signed in for a while!. I wonder how most people see ABB in New Zealand?. Since I have had a couple of beers and have recently been very unhappy with the electric motor industry in NZ .....Thought I should start some pub-chat. Who else thinks that big corporations are deliberately killing the Electric rewind/repair trade to better motor sales? ie: Baldor. Admittedly, they are a better motor than the old aseas, but seriously, they don't stand a chance against the superior Weg. There are so few people now who can be called a motor rewinder in New Zealand. This specialized trade is deliberately being crushed and knowledge is being lost. Well.. That's my rant for tonight. I will wake up tomorrow, open my eyes and face another day knowing that my trade is dying a slow and painful death.
  6. Had a problem with a tiny 20amp DC lucas generator recently. Was actually a foreigner (for my brothers tractor). Rewound the fields and inadvertently transposed them. A lot of times in the past especially with excitation fields of the self excited design you lose residual when you heat (or) do an AC drop test during the testing process. This is not normally a problem as you simply flash it back into life and away you go. BUT no matter how much I flashed this little sucker, it just refused to play ball. I had to pull it down and reverse the field winding for it to start self exciting again. It had me beaten for a long time until an "old timer" came along and told me that it was SO OLD that the laminations had established a memory and essentially turned from it from a temporary magnet into a semi-permanent and that by getting the poles mixed up (regardless of electrical polarity) makes it impossible to flash your old north to south. Anyway..It works now. I just thought I would share this as it may benefit somebody else in the future and it sure had me befuddled for a while. I would also be interested to know if there was an alternative (other than un-screwing pole pieces or reversing field) . Would sending AC at high current through the fields kill the residual thus allowing you to re-magnetize? Eurybates
  7. 50 mic for the start cap does not sound high enough. I think, do as Marke says...only maybe check current at startup instead...should be easy with clipon - if it does not drop before ol operates then starting torque is crap or motor is overloaded from seizedcompressor . Probably a reason why start cap is dead..try 130ish and see what happens. ps your two runs in par should be rated at 400ish Volts and the start should be about 230 ish..If not then your start cap is probably incorrect.
  8. Insulated bearings are another, yet expensive option. Just a little carbon shaft brush will do the trick (from retainer on stator to shaft of rotor)...will cost a couple of bucks. As for standards!.. Who knows, they are mostly bullocks anyway. Good luck.
  9. Wow No replies, I`m not surprised though really. It was not a compund!. It was a series with a bifilar winding. First time I have ever come across one. A Zero inductance coil (don`t ask). I`m still not convinced that it is doing anything at all! Anyway it is either strenghtening the magnetism or eating up stray flux ...maybe it was increasing Eff. who knows? it is interesting though, that it was the winding that had burnt from what appears to be overload conditions! All four consistant. Still interested in knowing more...May have to study a little Tesla to understand.
  10. Hi, I'm hoping somebody else has come across this wind and can explain. I have recently detailed the shunt/series pole pieces for a 4pole dc with interpoles. each pole piece has 4 wires out. 2 for series and 2 for shunt. no problems there..the large csa series winding is in top then wound clockwise to bottom and out to standard crossovers ..however the small csa (500 turns - 2 in hand) is in top wound clockwise joined at the ends and back out the top again! effectively cancelling itself out magnetically with 2 seperate leads out (the same yet opposite polarity). put a compass on them at test bench with zero pole results (as expected)..Whats going on? greatfull for any insights.
  11. Hi I came to post the same comment as sharath/Shartah!. Can't say I'm too happy that I'm older now than I thought I was already. On top of that I have to push back three times to go back one page.proving that It just gets harder as you get older. **beep** I did appreciate the belated happy new years email though. Best Regards Eurybates PS don't suppose you have a backup of old forum?
  12. The reason why nobody has replied to your post is most likely because it is very hard to see details of comm wear in the photo. It simply looks like a roller coaster. I can see there are dust grooves which is good!. The question should be "why has this happened now?" Have you recently had the machine serviced? Did you replace brushes and are they the correct grade? What about brush spring tension? When it was undercut, were the comm segments bevelled? You should have a ducting result sheet for exact (or to 2 decimal places) resistances. As for foreign contaminent ..there would be lots of thin little lines around comm. I think (going by the picture) that you have premature wear, where the brushes have been running!. In other words, I don't really know. You should take this machine to a motor rewinder/repairer shop or ring up a company who deals in supplying brushes to industry such as morganite carbon (thats not a plug) they are just an example I know of. They will take one look at the comm and tell you why. Sometimes it is worth spending the money now to get problems sorted before they get out of hand. Apart from the above...all I can suggest, is that you upload a better photo.
  13. Probably a bit late now, but just rewound a 400V 50Hz to 400V 60Hz for same application. May have been a much faster and cost effective alternative..... Just to have my say.
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