Rotary Phase Converters and 5 Wire 3 Phase Power for Robots?

    Hi Guys,

    I’m still trying to find out what I need to power my Motoman UP6 w XRC Controller.

    I’ve learned that I need to supply 5 Wire corner-grounded Wye power with a Neutral in addition to the 3 Phases and safety Ground.

    What do I need in order to meet this requirement?

    I imagine the RPC outputs 3 Phase “Delta”with no neutral. Is there a way to wire this to create a neutral? Or do I need an additional Delta to Wye transformer?

    Also, how critical is the RPC itself? Is a 3 Phase induction motor acceptable to use with oil-filled capacitors, etc to balance the load, or are there reasons why a 3 phase generator is needed for the Idler motor?

    Can someone PLEASE try to explain this stuff to me so I can move forward?

    Has anyone used an RPC to power an industrial robot? Do you have any experiences or revelations you can share with me?

    Many thanks!

    Deke

  • Go to Best Answer

    well, no offense but i have to say that you are certainly not making it easy to help you.

    for example you are referring to something (that i sort of recall) but you did not reference it, just started another topic.

    also you are dealing with one specific product (Motoman robot system) but you are asking for support in general section when you may be better served forum section dedicated to Motoman.

    then you are using this forum where people from all around the world are having discussion but you are not saying where in the world you are and what type of power grid or national standard applies to you.

    you mention 240V single phase and 480V three phase so am guessing this is possibly somewhere in the North America (possibly USA or perhaps Canada/Mexico) or at least that is where the robot came from.

    further, you are not sharing any info that would be useful to those of us that are not very familiar with Motoman. for example I find it odd that someone would ask for "5 Wire corner-grounded Wye power" and you did not link any info that confirms details of actual robot controller power requirements.

    wiring of 3-phase circuits is normally in wye or delta configuration. in most places on this planet power is delivered through power grid in AC form using transformers. delta is is commonly used at input (primary) and wye is used at output (secondary) of a transformer.

    in case of a wye, center is grounded and optionally used as neutral. advantage here is that same 3Phase system can be used also as a single phase supply without any conversion.

    in some cases delta may be the output and in such case corner grounded delta is one of options.

    there is also a delta with center tap but i don't think to have ever come across corner grounded wye.

    then you mention talking to RPC sales team but did you ever consider contacting robot manufacturer?

    and finally, there is also no mention of potential RPC model or link to a manual of catalog page.

    also robot is not a very stable load, quite the opposite. yet you di not mention application.

    there is a huge difference in dynamics between robots between polishing optics and robot doing pick and place. but that is not mentioned either.

    to me this looks like you are not very interested in getting an opinion or advice.

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    Hi panic mode,

    Thanks for your response... If I have neglected to include information or describe my situation well, I can assure you that I had not intended to be unclear or make it difficult for members to help me.

    I have posted several times over the past year asking for help in getting my robot powered without having access to 3 phase electricity. I have a Motoman UP6 arm with XRC controller, and I've tried posting in the Yaskawa/ Motoman forum, but thought that perhaps someone with another brand of robot might have had some experience using a Phase Converter and creating pseudo-3 phase power to run their robot - and so that's why I tried the General forum.

    Let me try to correct my previous post and give some more specific information:

    First, I live in the USA, New Jersey to be specific. I am installing the robot in my garage, where I have basic residential power service... Single Phase 220-240VAC.

    Much of what I've included in my previous posts is information I've gotten from members on RobotForum or articles I've found online. I am technically proficient to a degree, but I have no robot-specific education or job experience. I am also not an electrician or electrical engineer, and I never even heard of Delta or Wye power until I started learning what I would need to power my robot.

    What I've learned so far is mainly from users like yourself, Robodoc, Skyefire, dieselxj, Pcarbines and others who replied to my posts kindly giving me their opinions... The issue is that many of you seem to have differing opinions: Robodoc told me that I would need real 3 Phase power from the utility grid and nothing else would work. Others said that a phase converter would work well if it were large enough to handle the large current variations that the robot would cause.

    I'm sorry... I just realized that I got Delta mixed up with Wye ... I think it was RoboDad that mentioned "corner grounded delta"... Robodoc had said that the controller needed to have a Neutral bonded to the chassis, and I believe he had mentioned 5 wire with a neutral being necessary.

    The RPC I was thinking of is the American Rotary AD-5. My robot is roughly 2kVA/ 2HP, so I'm considering a 5HP RPC and hoping that will be large enough. Here is a link:

    http://americanrotary.com/products/view/…l-smart-series/

    But I've also been curious about cobbling together my own manual-start RPC with a 3 phase 5HP motor, various capacitors to help balance the load, heavy duty contactors, etc.

    In the literature for my robot, it says Power Requirements are approx 1.6kVA. I've also read up to 2.5kVA in other brochures/spec sheets. Some members have said that I probably won't need the full-rated current capacity, as overloads can be tolerated for short periods.

    If members that have gone through this (with whatever robot they have) will respond with their experiences/conclusions, I'll be able to use that knowledge to help figure out the best move forward for me.

    To end this very long post, I'll just add: If you (or anyone) has any thoughts on the above and wants to respond, I'd be happy to give you any info you might need to help me sort out my dilemma.

    Many Thanks!

    Deke

    Edited once, last by Dekatronic (April 11, 2022 at 4:27 PM).

    you continue to ignore tips and advice. you still refer to some past posts and you did not link them. clearly you think someone else should find time to do a selective forensic type of research in a busy place like this forum specifically to help you. your fate in humanity is greater than mine.

    specially since you still did not post details on your controller. i am not a Motoman guy and don't know the details on XRC. in fact i don't know how many XRC variants are there. i tried little research ad found that there is something called XRC-2001. so there may be KRC2002, XRC-2005 etc. you still do not provide any hard data so everything mentioned here is still no more than speculation. no link to a controller manual, no picture of the nameplate, no screenshot from the manual of power requirements... not very productive if you ask me.

    in fact all your so called "research" is bunch of vague opinions and speculations from anonymous guys on the internet (such as myself) who are careful not to say anything bold. so you still don't have a shred of evidence from real manual of you product or info from manufacturer. you are simply assuming that conservative tips and suggestions are somehow more important than actual info from the your product documentation?

    you have not heard of wye-delta, have no electrical experience and don't know if neutral is needed or not but you want to build own RPC converter and power a robot with it? sounds like asking first guy from a nearby bus-stop to do a bridge or airplane wing load analysis. i am starting to wonder what have you considered so far?

    maybe you are only considering getting some cheap second hand motor, figure how to turn it into RPC by watching a YouTube video by some kid in India and then connect robot to it... :winking_face:

    but i may be wrong...

    it may well be that you do have a plan in mind and test it with different loads before actually connecting robot to it. maybe you have right tools for the job and you plan to see how your RPC handles varying loads, measure voltage and current of each phase, frequency, etc and check for peaks of any anomaly and specially transients when load changes. maybe you also plan to add some small PLC or smart relays to ensure that RPC start is always using certain condition (no load for example). maybe you are planning to add protection to stop it if things get out of hand (overcurrent, overvoltage, undervoltage, overtermperature, GFCI).

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    Dear Panic,

    I am sorry that I didn't include all the information you thought I should have included... But I do not expect ANYONE to do research for me or provide easy, pat answers to my questions. I do not think that my fate in humanity is greater than yours - or anyone else's for that matter. But I must tell you that your attitude is making me think I should just find another website forum.

    Perhaps I thought this website was something that was intended to help and encourage people that are less knowledgeable and gifted than you obviously are. I humbly beg your pardon, sir!

    After yesterday's response from you, I did post some info in the Bio section on who I am and I included my website address, so you could see what I feel are my core talents. I am a cinematographer and film director who thinks they are somewhat handy and mechanically oriented. I am trying to learn what I need to know to get my robot working and use it as a camera platform to shoot some beautiful footage of jewelry, beer, liquor pouring, and other interesting subjects to attract new clients and hopefully continue to make a living.

    Like I said, I am NOT an engineer. I don't have an electrician's license and I've never worked with 3-phase power before. But I'm not an idiot either, and I resent your insinuations. I've been posting on this website in various forums for several months now, hoping to connect with SOMEONE who has done what I'm trying to accomplish, or knows things that I don't. Does every human being need to re-invent the wheel for themselves?

    Since you said you don't know the Motoman XRC very well, perhaps I should just thank you for your time and let you get on with your busy life.

    PS: My XRC controller is from 1999. It is called the XRC. Not an XRC 2001. I have whatever technical info that Yaskawa put up on their website. To me, it was less than enlightening in terms of what I was trying to find out.

    And if I did cobble together a RPC myself, I would definitely test the Hell out of it before trying to power up my robot. That leads to other questions I have: If the robot load and current demands keep changing, how effective IS IT to try to balance the RPC with Capacitors? Balance for WHAT? Heavy Load? Light Load? And what particular 3 Phase Motor should I even consider, because the leading RPC manufacturers talk about their custom-made Baldor motors with "special" windings. And do I need to have a voltage regulator between the RPC power and robot controller?

    These are some of the questions I have. There are no books that I've found that would help answer these questions. I've searched the web for information for more hours than I'd like to admit. But yet, here I am...still hoping to learn what I need to know.

    Someone who has traveled this route themselves could probably answer these questions in 10 minutes.

    So Thanks Anyway,

    Deke

    • Best Answer

    FYI, I do concur with what panic mode is saying and I can tell you, they are one of the most respective members here as they usually are one of the first to spare valuable free time and write lengthy replies to ANYONE.......do you think their responses took a couple of minutes to write....just think about that for a second.

    Firstly you need to appreciate this is an industrial robotic forum.

    Industrial and not domestic applications are where the majority of members knowledge, experience reside from.

    Secondly, moderating these boards and information from ALL members is based on 'their' free time, timescales and experience and not necessarily a priority to visit robot forum before they check their mobile phones for texts in a morning.

    Thirdly, experienced members are very unlikely to get involved due to liability possibilities as it's domestically related and not commercial and as there are no specific robot manufacturers documentation supporting domestic installations, so to point you to any reference is a big fat doughnut for starters unless a visiting member happens to have something relative to your topic.

    Fourthly, looking at your multiple threads (which is not allowed).

    The reason people create multiple threads is to try and get a faster response by the misconception of it reaching a wider audience, big mistake, it actually works against you.

    Especially in specific specialized areas as yours as it is very unlikely, someone whom has already taken this journey and achieved a success is likely to visit here again to offer support to others (depending on the individual intentions of course).

    So have you ever thought that maybe your threads need revising with more specifics?

    Unless someone has had success with an RPC and the exact system you are intending to use, then ALL information from ANYONE will be purely speculative and therefore, they may be reluctant to offer advice due to this and other liabilities, especially as it's domestic and not industrial.

    Quote from Dekatronic

    Someone who has traveled this route themselves could probably answer these questions in 10 minutes.

    Exactly my point, so unless 'that' person visits, reads and understands your post, you are left wanting.

    That is the nature of public forum's, get used to it.

    So I suggest the following:

    1. Contact Motoman directly and pose your question to their technical support, they will have been asked this many times and at least they will be able to provide the exact electrical specs that you could pass on to perspective RPC suppliers (whether you understand them or not is down to you).

    2. Why people do not contact OEM's and expect Robot Forum to provide immediate answers will baffle me till I push up the daisies.

    3. Revise your post (including removal of multiple threads (which is not allowed).

    4. Remove ALL the rhetoric from your posts, people get bored of reading and will not respond.

    5. Create ONE thread, in the OEM board, or the General board containing JUST your questions.

    6. Search the forum thoroughly, the below thread is a classic example, especially in specialized topics.

    The date and also the amount of posts the members have made is a clear indication 'that' person is not a regular visitor/poster.

    Phase converter for Staubli RX90 & CS7MB - Stäubli & Bosch Robot Forum - Robotforum - Support and discussion community for industrial robots and cobots (robot-forum.com)

    7. The above topic actually contains some information you could cross reference and explore further:

    - The robot may or may not be the same specs as yours.

    - Irrespective, it would provide a 'baseline' to investigate further.

    - Locate the specs of the above robot and compare it to yours.

    - Locate the specs of the RPC mentioned.

    - Contact the RPC supplier mentioned, quoting those specs and yours and see what they respond with.

    - Maybe ask if any 'trial units' are available.

    Whilst I can't offer any specific advice, the above areas are exactly how I would go about finding a solution and at the end of the day, you can read/research all you want, but at some point you need to make the leap to try something out......keeping a fire extinguisher to hand.

    Good luck in your search for a solution...... :top:

    Dear Kwakisaki,

    Thanks so much for your reply. I appreciate your clarity and your attempt to offer some help without including a side-order of Derision.

    To All Members Who Have Read My Posts: I apologize for wasting your time. I guess I got mislead by thinking of my robot as "Industrial", where I should have looked for forum that caters more to Hobbyists who happen to have an Industrial Robot, than to Industrial professionals.

    I kept posting thinking that I might have a better chance of finding the answers I need if I kept refreshing my question rather than letting it sink to the bottom of the pile. I must have missed the rule about NOT posting multiple times. Mea Culpa!

    Kwakisaki, do you recommend that I go back over my posts and Delete them all, except for this current one?

    Needless to say, I will not beat a dead horse by posting again on this forum. If a member has affinity with my situation and can offer some advice, I would be grateful.

    Kwakisaki, I will try following some of your other suggestions.

    Thanks to everyone for your help.

    Cheers!

    Deke

    Edited once, last by Dekatronic (April 12, 2022 at 2:24 PM).

    Quote from Dekatronic

    I have posted several times over the past year asking for help in getting my robot powered without having access to 3 phase electricity.

    and year later it is still not resolved. what does that tell you?

    Quote from Dekatronic

    I have no robot-specific education or job experience. I am also not an electrician or electrical engineer, and I never even heard of Delta or Wye power until I started learning what I would need to power my robot.

    i am an electrical engineer with years of experience, telling you what you should know.

    Quote from Dekatronic

    I'm sorry... I just realized that I got Delta mixed up with Wye ... I think it was RoboDad that mentioned "corner grounded delta"... Robodoc had said that the controller needed to have a Neutral bonded to the chassis, and I believe he had mentioned 5 wire with a neutral being necessary.

    GIGO principle... without sufficient and accurate data there is no good answer.

    and i've been reading your posts carefully to correct and clarify things.

    Quote from Dekatronic

    But I've also been curious about cobbling together my own manual-start RPC with a 3 phase 5HP motor, various capacitors to help balance the load, heavy duty contactors, etc.

    that is what most people reading your post would conclude. and they are cautious to not say anything that is unsafe to someone without necessary experience and qualification.

    Quote from Dekatronic

    In the literature for my robot, it says Power Requirements are approx 1.6kVA. I've also read up to 2.5kVA in other brochures/spec sheets. Some members have said that I probably won't need the full-rated current capacity, as overloads can be tolerated for short periods.

    speculation and hearsay without link or screenshot of actual document. you still think someone will just go to Motoman website, start digging for information. this is something you should do and just post link to specific files and pieces of information. you have yet to begin doing that.

    Quote from Dekatronic

    If members that have gone through this (with whatever robot they have) will respond with their experiences/conclusions, I'll be able to use that knowledge to help figure out the best move forward for me.

    this is industrial forum. industrial robots are normally powered by 3-phase power from the grid. very few people deviate from that. and there are very few people that offer help or share their experience. and even fewer would know about actual details that may help others. for them problem is solved and it works. very few would have any clue about switching capacitors, special windings, voltage regulation etc.

    Quote from Dekatronic

    In the literature for my robot, it says Power Requirements are approx 1.6kVA. I've also read up to 2.5kVA in other brochures/spec sheets. Some members have said that I probably won't need the full-rated current capacity, as overloads can be tolerated for short periods.

    that is true, robot slowly moving camera is not a very demanding load. robot wielding heavy payload very rapidly is.

    Quote from Dekatronic

    If members that have gone through this (with whatever robot they have) will respond with their experiences/conclusions, I'll be able to use that knowledge to help figure out the best move forward for me.

    agreed. but if you check, you will find that very few people are offering help. those people need help. your help. if you have a problem you need to compile and present the case the best you can with hard info and direct links.

    Quote from Dekatronic

    I do not expect ANYONE to do research for me or provide easy, pat answers to my questions.

    ....

    PS: My XRC controller is from 1999. It is called the XRC. Not an XRC 2001. I have whatever technical info that Yaskawa put up on their website.

    you claim one thing then say something exactly opposite. that is exactly why this is not moving in direction you expected.

    Quote from Dekatronic

    Like I said, I am NOT an engineer. I don't have an electrician's license and I've never worked with 3-phase power before. But I'm not an idiot either, and I resent your insinuations.

    ....

    That leads to other questions I have: If the robot load and current demands keep changing, how effective IS IT to try to balance the RPC with Capacitors? Balance for WHAT? Heavy Load? Light Load? And what particular 3 Phase Motor should I even consider, because the leading RPC manufacturers talk about their custom-made Baldor motors with "special" windings. And do I need to have a voltage regulator between the RPC power and robot controller?

    These are some of the questions I have. There are no books that I've found that would help answer these questions. I've searched the web for information for more hours than I'd like to admit. But yet, here I am...still hoping to learn what I need to know.

    my insinuation that you do not have right skill, tools or experience is confirmed by your own words. you do not know what you are talking about and do not know how to collect, organize, present or evaluate technical information. i am not saying that you are not smart but this is not your cup of tea.

    people doing research may stumble at Wiki. not the greatest or most reliable resource but it does have decent info on questions you have. sorry if my posts rubbed you the wrong way, just trying to help. maybe just start considering replies and get with the flow, you will find results much faster.

    take care and good luck with your project

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    Dear panic mode,

    Thanks for your reply.

    Well, I tried to present my questions as clearly as I could... On other forums that I've joined in the past, if a member that is trying to help another needs specific information in order to understand the issue -for example a photo or specs - they usually ask the person that posted the question to provide the additional info that would help them answer the question. I could easily fill my posts with Yaskawa manuals, photos of the inside of my controller, etc. - but I thought this would be "jumping the gun" and

    didn't want to upload tons of files without knowing if they were needed. I'll try to upload the Yaskawa manual for the XRC controller in this post. If I understood correctly, I am only allowed one attachment per post.

    I guess I see now that, to you, I am like some of the advertising clients I used to deal with who would ask me for my recommendations on the best camera for their personal use. I would try to provide an honest answer, but it was ludicrous in a way because there are just too many variables to be able to provide a really meaningful answer. I am sorry that I don't know more.

    Being an electrical engineer, you seemed to be the type of person who might know the pitfalls of what I'm trying to do, and might help me to avoid unnecessary disasters. It's like asking my doctor questions about some physical symptoms that might be bothering me... I could Google all the medical sites and try to cram a medical education in a few days time, but it would not come near having someone who is knowledgeable and experienced take a look at the problem and give me their educated opinion.

    In any case, I sincerely want to thank you for your time and effort. I will go back and delete all my past Posts, and will hope that someone who has had an experience that might help me - will see this post and respond.

    Lastly, here is the brochure for the XRC controller ... It is not as informative as the full manual, but it is all I could find on the Motoman site that was under 8MB. I will post this for anyone that is interested.

    Best Wishes,

    Deke

    do not worry about past posts. lets make sure that no new threads are created on same issue for same robot. please just stick to the details relevant to the problem itself. avoid flowery descriptions and unnecessary fluff like mention of other forums, doctors etc.

    you do not need to post entire file, a simple link to a file would be sufficient. screenshot of some detail could also be a compact and clear statement (and confirmation) of some detail.

    the file you shared is just a sales flyer and the specs shown are not supporting anything you believed:

    there is no 480V, no voltage tolerance, no mention of FLA or power, no mention of neutral conductor or how the supply is referenced etc. that is a good indication that document is only glossing over some key points without going into details.

    as an example of more detailed info, here is excerpt from some other robot manual:

    note the absence of colors and other distractions. also that document is more than 200 pages long. info on power requirements is rather specific mentioning voltage tolerance, reference to phase symmetry, power etc. mentioned phase symmetry and grounded neutral rule out delta configuration and specially corner grounded delta. well one could still use delta but with help of isolation transformer that would convert the delta to wye.

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

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