Single phase 240 vs 3 phase 240 into dyn4

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Thread: Single phase 240 vs 3 phase 240 into dyn4

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    Default Single phase 240 vs 3 phase 240 into dyn4

    I have 2 servo driven spindles on single phase 240 that are not performing as they should according to specs. One of them is the 1.8kw driving my mill turn spindle. It will give a lost phase fault if i run it faster than 2700rpm and horsepower is also lacking. Maybe a horse and a half before it also gives lost phase fault. Servo is supposed to run at 3k max and nearly 3 horsepower continuous, much higher peak. Been running that one for a long time and living with it since its enough power for most of what i do but the full 3k rpm would definitely be nice.

    Recently i built a servo driven bt30 with a 1kw servo and it is having the same issues. Supposed to run at 5k max and 1.5hp continuous. Faults at 4500rpm and about 0.8hp.

    I have checked my line voltage and it is at 238 so no problem there. The max rpm issue on both servos is the same with nothing attached to the shaft. Ive been talking back and forth with dmm to try and solve the issue, but its taking a while to go back and forth with emails. He mentioned that sometimes residential power can have issues providing enough power and there is a firmware that might address the rpm issue. Not really sure why single phase 240 would behave different in residential vs commercial, but the firmware change could hopefully help
    Still waiting for a response from dmm about sending drives in for update. Seems odd though, i always assumed dmm was commonly used by hobbiest and small businesses, not uncommon to be on residential power. So why don't all drives have this firmware update?

    Im starting to wonder if the real fix is 3 phase power. Is it likely my servos would perform closer to specified rpm and power on 3 phase? The specs show no difference for single phase vs 3 phase, but maybe this was a mistake or a lack of single phase testing. I noticed many other drives have derated specs for single phase.

    If 3 phase will help, is there any issue with a thousand dollar 5hp rotary converter? Do i need something higher quality for something like this? The 2 servo spindles dont run at the same time so i dont think i would need more than 5hp.

    Thoughts?

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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    Quote Originally Posted by QuinnSjoblom View Post
    I have 2 servo driven spindles on single phase 240 that are not performing as they should according to specs. One of them is the 1.8kw driving my mill turn spindle. It will give a lost phase fault if i run it faster than 2700rpm and horsepower is also lacking. Maybe a horse and a half before it also gives lost phase fault. Servo is supposed to run at 3k max and nearly 3 horsepower continuous, much higher peak. Been running that one for a long time and living with it since its enough power for most of what i do but the full 3k rpm would definitely be nice.

    Recently i built a servo driven bt30 with a 1kw servo and it is having the same issues. Supposed to run at 5k max and 1.5hp continuous. Faults at 4500rpm and about 0.8hp.

    I have checked my line voltage and it is at 238 so no problem there. The max rpm issue on both servos is the same with nothing attached to the shaft. Ive been talking back and forth with dmm to try and solve the issue, but its taking a while to go back and forth with emails. He mentioned that sometimes residential power can have issues providing enough power and there is a firmware that might address the rpm issue. Not really sure why single phase 240 would behave different in residential vs commercial, but the firmware change could hopefully help
    Still waiting for a response from dmm about sending drives in for update. Seems odd though, i always assumed dmm was commonly used by hobbiest and small businesses, not uncommon to be on residential power. So why don't all drives have this firmware update?

    Im starting to wonder if the real fix is 3 phase power. Is it likely my servos would perform closer to specified rpm and power on 3 phase? The specs show no difference for single phase vs 3 phase, but maybe this was a mistake or a lack of single phase testing. I noticed many other drives have derated specs for single phase.

    If 3 phase will help, is there any issue with a thousand dollar 5hp rotary converter? Do i need something higher quality for something like this? The 2 servo spindles dont run at the same time so i dont think i would need more than 5hp.

    Thoughts?
    You never want to use an RPC on any servo drives unless it is the last resort, it can be done but must be balanced very well, you would need a line Reactor and a Power filter before the drives if you used a RPC

    I would say there firmware update will be right if there is a problem with that side of it, they test extensity with single phase power, but everyone's supply can be slightly different mine is 245v

    There normally is a limit on RPM related to voltage supply

    What is your Main supply Circuits Amp rating

    Mactec54


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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    Quote Originally Posted by mactec54 View Post
    You never want to use an RPC on any servo drives unless it is the last resort, it can be done but must be balanced very well, you would need a line Reactor and a Power filter before the drives if you used a RPC

    I would say there firmware update will be right if there is a problem with that side of it, they test extensity with single phase power, but everyone's supply can be slightly different mine is 245v

    There normally is a limit on RPM related to voltage supply

    What is your Main supply Circuits Amp rating
    200a service

    When i look at a couple other servo brands, they have derated specs fir single phase amd the numbers are lining up pretty much right on. Clear path shows an 11% reduction in rpm on single phase and thats about what im seeing. Just coincidence?



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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    Heard back, they said 3 phase wont help much. Going to send both in for firmware and lighten my main pulley as well. He said the current inertia of it is really pushing its limits and could be cause for the faulting



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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    Quote Originally Posted by QuinnSjoblom View Post
    Heard back, they said 3 phase wont help much. Going to send both in for firmware and lighten my main pulley as well. He said the current inertia of it is really pushing its limits and could be cause for the faulting
    The only DMM that have a derating is for the Dyn2 which are low voltage drives and use the same motors up to 750w

    That was my thoughts as well but you said it did it with no pulley so I did not post, servos in general don't react well if the inertia is around or close to the motors max

    You did not say in your other post if you are using a Braking Resistor which would help when slowing down, if not it will fault out

    DMM have done extensive inertia testing so will know what will work and what will not, I built most of there test rig for there inertia testing

    Mactec54


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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    Did you get a resolution to this because ive been pushing **** uphill with it for the better part of two years?



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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    I have also had this issue to a degree. I can use the motors up to 2000 rpm just fine but if I try to push them harder under analog voltage they over current fault. I can get them to move at speed under position control but I have to have all of the acceleration settings turned down far to get them to not fault. They are driving axis and replaced motors half their size. I am running them on residential power, 240 volts, 200amp supply, line filter installed, noise filters etc.

    Also the drives encoder response is 5ms behind the input commands. So the encoder feedback is nearly useless for using the drives in analog control with linuxcnc controlling position.



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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    What did DMM say about this? Cause i got the royal run around. I suspect if i posted my email chain allot of people wouldnt buy from them anymore.



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    Default Re: Single phase 240 vs 3 phase 240 into dyn4

    I have a lot of emails from them back and forth explaining things but none of it helped. Initial blame was placed on my wiring, which was exactly how the manual stated. It then went to a bunch of different suggestions in between but none worked.

    The email chain left off with them claiming that linuxcnc was at fault and they didn't want to accept my scope images that i sent them showing that the drives encoders had a slow response. My issue attempting analog control in speed mode was that since the drives did not send timely encoder feedback to the control, the control would cause the drives to over accelerate to get to speed and fault out.

    I just gave up on them. I switched them to position mode and turned the acceleration way down and even then the Z axis 1.8kw cant reach full speed. Sadly my G0704 with steppers can accelerate faster than the DMM.

    I also had issues with the drives loosing all of their settings after a fault and power cycle but I could not replicate it to prove it. They would basically revert back to some previous setting occasionally after a fault.

    Overall I did not get what I thought I was paying for and they don't function in many of the modes they are advertised as having. If no one believes me I would love to see a post where someone has large DMM servos on an axis, in speed mode, analog control and the controller running the position loop. I was unable to find anyone else who had success. There are a couple posts in dynomotion if I remember where they got them to "work" but they observed the same encoder issue and used a filter to get around it. But this won't solve synchronized motion issues if you are masking the issue.



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Single phase 240 vs 3 phase 240 into dyn4

Single phase 240 vs 3 phase 240 into dyn4

Single phase 240 vs 3 phase 240 into dyn4