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  1. Replies
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    Rheostat question for 2hp DC motor

    I have a 2hp DC lathe motor, shunt wound, drawing 8 FLA and RPMs from 400 -2000. It all runs off an old school rectifier from an 220ac outlet.

    The rheostat that is on there now (not original but...
  2. Thread: VFD for DC motor?

    by jhg
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    15,528

    My lathe is a model 25. 20 inch swing, # 4 morse...

    My lathe is a model 25. 20 inch swing, # 4 morse tapers, 8 foot bed w/power tool carriage and all the tooling like tool rests, steady rest, face plates, chucks, duplicator and etc etc.

    It is a...
  3. Thread: VFD for DC motor?

    by jhg
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    Its an Oliver pattern makers lathe. About 2300lbs...

    Its an Oliver pattern makers lathe. About 2300lbs worth. I tried posting some pictures but they are too big.
    All the name plate data has been posted.
    jhg
  4. Thread: VFD for DC motor?

    by jhg
    Replies
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    15,528

    Thanks for the explaination regarding VFD's/DC...

    Thanks for the explaination regarding VFD's/DC motors.
    I certainly don't want to do anything that would jepordize the motor. I plan on using this lathe without having it rewound, $$$.
    The only...
  5. Thread: VFD for DC motor?

    by jhg
    Replies
    25
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    15,528

    I should have mentioned this is a direct drive...

    I should have mentioned this is a direct drive motor, unique to the rest of the machine. No pulleys, and there is no way I would ever replace the motor. Its 1926 vintage, all original and just...
  6. Thread: VFD for DC motor?

    by jhg
    Replies
    25
    Views
    15,528

    VFD for DC motor?

    I have a lathe with a (giant) 2hp shunt wound single phase DC motor that runs via a rectifier and has an infinite speed range between 400 and 2000 RPM's. It draws 8 amps @ 230 volts and has a 1 hour...
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    Using the tablesaw would be the easiest solution....

    Using the tablesaw would be the easiest solution. Can I wire two 30 amp 3 phase outlets on the same circuit and achieve this? One plug to the planer and one plug to the saw.

    jhg
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    I have a FW design 10hp RPC that works great. Now...

    I have a FW design 10hp RPC that works great. Now I have two 7.5hp load motors in my shop- a wood planer and a tablesaw.
    The motors are both made by Baldor and are of the same rpm. Identical motors...
  9. Replies
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    You still need to cool the idler using its fan. I...

    You still need to cool the idler using its fan. I wouldn't pull it off.
    Buuuut.....
    You could use an auxillary fan to cool it though- a quiet desk fan for example, in place of the OEM noise maker-...
  10. Thread: Static or rotary?

    by jhg
    Replies
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    3,284

    Resist the siren song of a static converter. The...

    Resist the siren song of a static converter. The primary initial advantages of a static- lower cost and seemingly easier application are soon offset by limited performance.

    I have very little...
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    What are some things I should be looking for in a...

    What are some things I should be looking for in a used transformer to step up fron 230 3 phase to 460?

    Are there things to avoid? Do they call out the winding material?


    I will be adding this...
  12. Replies
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    Nameplate data is as stated in first post. It is...

    Nameplate data is as stated in first post. It is a 3 phase motor with internal overload that equals two wires.

    1)There are 10 leads from the speed drum switch to the motor not including the...
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    Thanks everyone. I can easily upsize my breaker....

    Thanks everyone. I can easily upsize my breaker.

    Outside of that issue, where it seems I have been fortunate in that my machines must not be working too hard, even though I seem to be :0) are...
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    Wel,l not really. An unloaded 5hp motor should...

    Wel,l not really. An unloaded 5hp motor should not be tripping even a 30 amp breaker that also feeds an RPC.

    Anything to contribute to the motor questions?
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    I have a three speed 5hp induction motor. It...

    I have a three speed 5hp induction motor. It will only start on the slowest speed- 8xxrpm without tripping the breaker. It will run on the second speed 17xxrpm, but trips the 30 amp breaker feeding...
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    Aaaah, so you add caps AFTER the first load...

    Aaaah, so you add caps AFTER the first load motor? In this way their influence is only brought "online" when the second motor is added? This is how you get around high phases at the idler. Now I...
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    Its not "upgrading" to up size the circuits that...

    Its not "upgrading" to up size the circuits that service the idler when the result is a less balanced
    RPC. (if you then run more than 7.5hp load) Its kept at 7.5hp to produce better balanced...
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    7.5 hp single motor or 7.5 hp total motors. ...

    7.5 hp single motor or 7.5 hp total motors.

    The circuits in Fitch's plan are sized for 7.5 hp total. Not more than that. My assumption is he did that to keep costs within a resonable realm for an...
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    I think its worth pointing out the FW plan is...

    I think its worth pointing out the FW plan is sized only to 7.5 hp to keep the idler capacity vs load motor ratio within a reasonable window for the generated leg to produce a fairly "clean" 3rd leg....
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    My motor was gone into and changed from 440 to...

    My motor was gone into and changed from 440 to 220 3 phase. They clearly did not rewind the whole motor. They went into one end and brought out 3 new leads. This is clearly seen by the new leads and...
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    Ha Ha- it turns out the motor has been re-wound...

    Ha Ha- it turns out the motor has been re-wound already- changed to 220!

    Thanks everyone. I'll be able to use what I learned here anyway- one day there will be a need for 440 in my shop.
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    My RPC is under 250 all three legs. IIRC they are...

    My RPC is under 250 all three legs. IIRC they are 246-248 or so, load motor running.

    I think I am dreaming that this machine is going to have nine leads hidden under the box. Its a special motor...
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    Thanks for the tip. I was just doing a search and...

    Thanks for the tip. I was just doing a search and just found that. I will see this weekend whats inside. Hoping for the best. I am on the hunt for a transformer too, just in case.
    This machine has...
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    Dumb question- why can't the motor be wired 220?...

    Dumb question- why can't the motor be wired 220? Does it care as long as it sees the voltage it needs?
    jhg, thinking that he'll get out of this somehow...
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    I have a 10hp 220v RPC. I have a newly aquired...

    I have a 10hp 220v RPC. I have a newly aquired machine with a 440 only motor.

    What is my path of least resistence cost & effort wise?
    Is it to build a 440 capability into my RPC, or can/is it...
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