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  1. P

    Insufficient Electrical Supply? Manual lathe slow to start

    Ok so a happy ending to this saga: I tried adding 100uF capacitors to each capacitor bank (bringing it to 150 uF L1 & L3) and 250 uF (L2 & L3). This boosted the voltage to my generated legs quite high at idle (275V ish). Fired it up anyway and it helped a little, but not a huge change, and I...
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    Insufficient Electrical Supply? Manual lathe slow to start

    Sorry I was out of town for the weekend and away from the computer. Thanks very much for all the thoughtful replies! I'm with JST on this one, and others that have suggested the rpc is the weak link. To clarify a few themes that I might not have explained very well: Yes the mfg recommends 6awg...
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    Insufficient Electrical Supply? Manual lathe slow to start

    Thanks for the reply - It's a good point about the WEG. I replaced it with a TEFC cast aluminum instead of the original ODP (whatever Japanese motor was in there since the 70s). The motor frame size now is a 4 Kw where it used to be 3.7, so a little bigger. Also a good point about running...
  4. P

    Insufficient Electrical Supply? Manual lathe slow to start

    Ok, I guess I didn't fully understand that post. Are you saying: disconnect the 10hp rpc idler motor from the rpc box connect the 5hp lathe motor (without belts) to the rpc box run the rpc, and see that the 5hp motor starts quickly like the 10hp does. If it starts slowly then the new 5hp motor...
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    Insufficient Electrical Supply? Manual lathe slow to start

    Thanks this is really helpful. It puts me in the pocket of what the phase converter company suggested. I'll be adding 100uF to each leg so it'll be 150uF and 250uF. I guess I'll just keep an eye on the voltages. Yesterday I ran an extra 10gauge wire across the shop and spliced it into the...
  6. P

    Insufficient Electrical Supply? Manual lathe slow to start

    My bad, it's 8AWG in conduit, which is rated to 50A. Edited my post above to correct, thanks for catching it
  7. P

    Insufficient Electrical Supply? Manual lathe slow to start

    California, definitely 60hz. Just got off the phone with the phase converter company and they recommended boosting the generated leg with extra capacitors. They said 100-200 uF per line. Anyone have an opinion on that? Seems easy enough and inexpensive. The current run capacitors are: L1 -> L3...
  8. P

    Insufficient Electrical Supply? Manual lathe slow to start

    Wow, incredible, thank you for all the great and prompt responses. I will try to give some more info related to the above answers: To the last post: that was my old thread. I reposted here because it's become a more generic electrical issue and the problem isn't solved Keep in mind that this...
  9. P

    Insufficient Electrical Supply? Manual lathe slow to start

    I'm having continued issues getting my manual Mori Seiki lathe (MS-850) to come to full speed quickly. This was a machine-specific question but I'm moving it to the general forum because I've narrowed it down to a more general electrical issue. The problem is: at startup, the motor starts...
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    Slow Startup on Mori Seiki MS-850

    Thanks From the 'Line in' connections to the end of the thermal relay are all 0.5-0.7 Ohms with the contactors pushed in. The motor connections are buried now so I measured just upstream of the motor terminals. I guess that rules out the contactors and the relay... Line to line (measured at...
  11. P

    Slow Startup on Mori Seiki MS-850

    Ok so this is curious. I bought a new WEG 00418ET3EAL112M-W22 motor and got it all hooked back up. This motor is 4kw and the old one was 3.7, so I figure no biggie, same frame size and a little extra power never hurt. But strangely, when I turn the machine on, it's actually the same issue - the...
  12. P

    New Motor Issues on Mori Seiki Lathe

    JST that fixed it! One leg of the transformer was connected to the generated leg. Switched it and it fires up no problem. Thank you! This thing is almost ready to rip
  13. P

    New Motor Issues on Mori Seiki Lathe

    Good point, I will check that. I was just digging into the transformer actually. Here is a photo of how it's currently wired. I saw another post that jumped the high voltage coils like the way that I'm drawing. Should I jump the high voltage coils like this?
  14. P

    New Motor Issues on Mori Seiki Lathe

    I replaced the motor on my Mori Seiki MS-850 lathe that I'm trying to get fired up. I replaced it because it was spooling up very slowly, and I took off the old motor and it was full of what looked like drywall dust and in bad shape. So I replaced it with a brand new WEG that fits the same frame...
  15. P

    Slow Startup on Mori Seiki MS-850

    That's a really good point. I hadn't considered that. It has 220/440 on the original 1973 motor plate. But it only has the 3 main wires, so maybe it was somehow wired internally for the higher voltage. Either way, a 2023 motor will get it ripping Thanks I feel like I lucked out. If you're...
  16. P

    Slow Startup on Mori Seiki MS-850

    I pulled the motor apart and it was filled with dust and looked terrible. It was hard to tell what was going on, but the insulation on the windings looked black in places and it was quite brittle, showing signs of overheating. Even though there weren't any shorts phase to phase or to ground...
  17. P

    Slow Startup on Mori Seiki MS-850

    haha thanks. I'm stoked I pulled the brake off completely to make sure it really wasn't binding and it still has a slow ramp...
  18. P

    Slow Startup on Mori Seiki MS-850

    I'm setting up a nice clean Mori MS850, but there is a problem where it takes longer than it should to spool up to speed. For example 500 rpms takes about 5 seconds to get to speed, 1000 rpms takes a good 12 seconds to ramp up. My friend has the exact same machine and his is very snappy. Not a...

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