545,767 active members*
1,834 visitors online*
Register for free
Login
IndustryArena Forum > MetalWorking Machines > Fadal > Bypassing Transformer on Fadal VMC15 (Operating in single phase)
Results 1 to 16 of 16
  1. #1
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    So i'm sure this sounds kinda dumb at first, but lets start with what the machine requirements are. 240V at 60Hz. That is the whole point of the transformer right. To take the variable power that you might have at your facility i.e. 210V, 220V, 230V, 240V, 250V, 260V, and to output at 240 volts... I'm assuming that is the point.

    So my input voltage at the panel is 121v on one leg at 123v on the other. Measures 241v across them. Sounds pretty perfect to me. Can I just by-pass the transformer completely and run power right to to the output side of the transformer? Gotta keep the surge protector in the circuit to. Obviously I would unhook the transformer from the loop. I'd probably just leave it in the machine though.

    The whole point to this is not to have to wire up the phase converter. Building an outbuilding for my machines and have power out there and put some lights in last week, but need to do insulation and sheet rock and maybe even floor epoxy if the funds become available. I know that the machine will only run at %65 power but I don't forsee that as a problem. I'm a one man show with a day job hogging and super speed is not my forte.

    I want to do the phase converter right and I'm thinking I might actually mount it up in the rafters and run a sub panel down the wall. (That way I don't have to listen to it)

    So the bottom line the million dollar the reason I post was to ask..... I'm I just being stupid?

  2. #2
    Registered
    Join Date
    Nov 2003
    Posts
    287

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    I have my VMC 15 running on single phase just like you suggested. I don't know what drives you have but mine require 110v and the VFD for the spindle will run on 220V single phase. I heard that you lose some spindle power by like 20% but haven't noticed it. T think there is a wiring diagram in one of the Fadal service manuals for wiring single phase but I can't find it right now. If I remember correctly it does matter which legs of the VFD you feed the single phase to. The manual I was looking at was for the VFD itself.

  3. #3
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Quote Originally Posted by vertcnc View Post
    I have my VMC 15 running on single phase just like you suggested. I don't know what drives you have but mine require 110v and the VFD for the spindle will run on 220V single phase. I heard that you lose some spindle power by like 20% but haven't noticed it. T think there is a wiring diagram in one of the Fadal service manuals for wiring single phase but I can't find it right now. If I remember correctly it does matter which legs of the VFD you feed the single phase to. The manual I was looking at was for the VFD itself.
    Just to clarify. You have a 3 phase transformer and just completely bypassed it? Thats my plan. Some people buy the T813/T814 Single phase transformer, but what I am getting at is I don't think I need to step my voltage up or down. I have the manual for the VFD in the back of the machine so I'll take a look at the wiring diagram.

    Would be kinda nice to avoid dealing with 3 phase right now. I'm thinking I might try to epoxy the floors so want to try to move machines around alot. May not happen I dunno.

    Thanks

  4. #4
    Registered
    Join Date
    Mar 2016
    Posts
    40
    Quote Originally Posted by breathe View Post
    Just to clarify. You have a 3 phase transformer and just completely bypassed it? Thats my plan. Some people buy the T813/T814 Single phase transformer, but what I am getting at is I don't think I need to step my voltage up or down. I have the manual for the VFD in the back of the machine so I'll take a look at the wiring diagram.

    Would be kinda nice to avoid dealing with 3 phase right now. I'm thinking I might try to epoxy the floors so want to try to move machines around alot. May not happen I dunno.

    Thanks
    Installation manual pages 69-72 helps out...

    http://www.flintmachine.com/pdfs/fadal-manuals/maintenance-manual/Installation_Procedures.pdf

  5. #5
    Registered
    Join Date
    Nov 2003
    Posts
    287

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Quote Originally Posted by breathe View Post
    Just to clarify. You have a 3 phase transformer and just completely bypassed it? Thats my plan. Some people buy the T813/T814 Single phase transformer, but what I am getting at is I don't think I need to step my voltage up or down. I have the manual for the VFD in the back of the machine so I'll take a look at the wiring diagram.

    Would be kinda nice to avoid dealing with 3 phase right now. I'm thinking I might try to epoxy the floors so want to try to move machines around alot. May not happen I dunno.

    Thanks
    Yes, mine had the 3 phase transformer and was run previously on 3 phase power. I completely bypassed the transformer and feed 110v to the servo drives and 220v to the VFD. Runs perfect.

  6. #6
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    So according to this link

    https://www.fadalcnc.com/media/pdf/P...ranformers.pdf

    They appear to want you to stay under 240V. So I've got an idea. Again might be dumb, but I think I'll try it tonight. If I need to step my voltage up or down I could just run it through the two lines on the transformer and leave the 3rd input empty. This would allow me to basically use the 3 phase transformer as a single phase transformer. Again might be dumb but I dunno, might work ok. I'm hoping I can run some juice to it tonight and see what happens. Shouldn't do anything bad. In the end I'll probably just bypass the whole thing. Voltage drop over that distance ought to bring me under the 240V limit. I'm only 1volt away anyway.

  7. #7
    Registered
    Join Date
    Nov 2003
    Posts
    287

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    My guess is your measuring 241V at your panel, but the voltage at the machine could easily drop 1v due to distance to machine and also load. I wouldn't think that 241V versus 240V at the VFD would matter.

  8. #8
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Quote Originally Posted by vertcnc View Post
    My guess is your measuring 241V at your panel, but the voltage at the machine could easily drop 1v due to distance to machine and also load. I wouldn't think that 241V versus 240V at the VFD would matter.
    I'd agree with that. I spoke with my maintenance supervisor at work and he considered a few extra volts to be nill. His response was that the power companies won't guarantee anything better than +/-%5 anyway. The electronics have to be built to handle some fluctuations.

    I did bypass the transformer tonight. I jumpered line 2 and 3 together on the Vector drive cause is said to do that in the manual, but I'm wondering if that was a mistake. Vector drive showed an internal Temp Fault when I hit the switch the first time. I turned power off and cycle back on and now the lcd just flickers. Hoping the Drive isn't fried. (Wonder if I should try without line 2 engaged on the vector drive. the transformer schematics seem to indicate that. I jumpered because the vector drive manual said to do so.

    Hitting the machine green power button makes no noise on the machine. Monitor comes on though. I can't move any of the axis though cause when I press jog it give me an axis overload #3 alarm on all three axis and resets the amps. Not sure what the issue is. Nothing getting hot and there is no magic smoke so far so I guess I just gotta start plugging away and the diagnosis. Hard to tell what it could be. Machine was not under power for 3 years when I bought it.

    All 3 amps are flashing red leds at me when I look in that cabinet. Not sure if they are doing that before I hit the green button or not. Sounds like the error could be coming from a communication issue. Computer tells drive to move motor. Motor doesn't move Drive maxes everything out and motor doesn't respond axis faults.

    Who knows. I'm no cnc mechanic, but I may be by the time I'm done.

    Thanks for the help.

  9. #9
    Registered
    Join Date
    Nov 2003
    Posts
    287

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    I would check voltages at drives and computer power supply to start. Was machine functional before? I think this the VFD manual that i used for wiring, I am not see the jumper, on the VFD


    http://itscnc.com/images/tech%20docs...-1%20v11-1.pdf

  10. #10
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Quote Originally Posted by vertcnc View Post
    I would check voltages at drives and computer power supply to start. Was machine functional before? I think this the VFD manual that i used for wiring, I am not see the jumper, on the VFD


    http://itscnc.com/images/tech%20docs...-1%20v11-1.pdf
    Hmm, I'll try without the jumper and see what happens. Hope I didn't screw it up by jumpering.

    Checked the power supply. Its toast. At least its not running. Not showing voltage going in or out. I was kinda confused thought. The output side of the power supply board had dc 12v and 5v at some of the terminals. Not sure where thats coming from. Certain isn't the computer power supply.

  11. #11
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Quote Originally Posted by breathe View Post
    Hmm, I'll try without the jumper and see what happens. Hope I didn't screw it up by jumpering.

    Checked the power supply. Its toast. At least its not running. Not showing voltage going in or out. I was kinda confused thought. The output side of the power supply board had dc 12v and 5v at some of the terminals. Not sure where thats coming from. Certain isn't the computer power supply.

    I removed the Jumper and that didn't change anything on the VFD. I also switched power from L3 to L2 on the VFD and that also didn't seem to do anything, but there may be other issues at hand.

    I don't think the DC power supply is working. Which explains that amps being out. I've got a decent 650Watt computer power supply that can take its place. May get a chance to wire that in tomorrow. Tired now, gotta get some sleep.

  12. #12
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Apparently I don't know how to use a multi-meter. power supply fan is dead but power supply appears to be working. (I was checking voltage from ground to the terminals. Voltages looked good when I measured from the negative to the terminals. That confuses me though. Should I have a separate machine ground hooked up?

    Looks like input voltage to the amps is 124v AC which is where it should be. Voltage across the big blue capacitor is 10V DC but it should be 160V DC. Somethings wrong there. Not sure what.

  13. #13
    Registered
    Join Date
    Nov 2003
    Posts
    287

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    A dedicated ground would be good. You do have 2 hot legs and a neutral wire going to the machine, correct? I believe the voltage at the big blue capacitor is were the drives get their power., This should be what ever the drives require, If not check power feeding this power supply.

  14. #14
    Registered
    Join Date
    Jun 2010
    Posts
    98

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    So I decided that troubleshooting with my changes thrown in the mix was probably causing issues that weren't accounted for so I bit the bullet and wired up the phase converter this weekend. I didn't do anything fancy just hard wired it to the knife switch. I've got just over 240v on the good legs so I jumpered for 250v and that brought it down to around 236v so that good. The wild leg was reading 260-262v so I jumpered that for 260 but it didn't drop much on the output side of the transformer. Not sure if its worth trying to step down the wild leg, but that's what I tried to do.

    Turned the machine on and now I'm getting power to the amps (Green lights) Drives are still flashing red leds, but I can jog the machine now so I'm not sure if that is a bad thing or not.

    VFD in the back of the machine still just has flickers on the LCD. and when I try to run it in MDI I get two messages. First I'll get #9 line fault which means its not getting the 12V ready signal from the drive. Then it tries to reset and the next error I get is #10 Spindle motor overload. So I got something messed up there. May have a fried drive I dunno. Heard some people have tossed the drives and switched to yasakawa drives. Going to see if I can find an issue with the vfd and then start looking for replacements. May be a blow capacitor or something in the drive. I hear you can have them repaired for around $1500.

    Anyway I'll probably start a new thread for the drive. Thanks for your input will try to remember to update if I find a quick/easy solution.

  15. #15
    Registered
    Join Date
    Jun 2015
    Posts
    37

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Ever get a solution to this? Just bought a vmc10 and would sure be nice to not have to buy a transformer or phase converter as I don't plan on using over 7-8 hp of the machine anyways

  16. #16

    Re: Bypassing Transformer on Fadal VMC15 (Operating in single phase)

    Quote Originally Posted by vertcnc View Post
    Yes, mine had the 3 phase transformer and was run previously on 3 phase power. I completely bypassed the transformer and feed 110v to the servo drives and 220v to the VFD. Runs perfect.
    I'm pulling this from an old thread, but I have a 3 phase VMC 3016 and would like to run it single phase. Transformers are all but impossible to find and too expensive for me, so I was hoping you could share what you did to convert your machine over and if there have been any issues since.

Similar Threads

  1. Replies: 8
    Last Post: 06-14-2021, 01:42 AM
  2. Fadal VMC15 convert to single phase
    By narleyskier in forum Fadal
    Replies: 2
    Last Post: 05-18-2015, 03:34 PM
  3. Convert three phase transformer to single phase?
    By jimjovan in forum General CNC Machine Related Electronics
    Replies: 5
    Last Post: 09-16-2013, 11:32 PM
  4. 813 or 814 single phase transformer pic
    By zcases in forum Fadal
    Replies: 2
    Last Post: 06-19-2012, 10:40 PM
  5. Single phase back to 3 ph VMC15
    By davisboys in forum Fadal
    Replies: 4
    Last Post: 04-06-2006, 01:26 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •