Home JGAurora A5 & A3S Modifications & Upgrades

Safe A3S Power Supply Replacement

jollypikejollypike Posts: 12Member
edited April 2018 in Modifications & Upgrades
I know that people recommend an inexpensive LED power supply to replace the woefully underpowered power supply shipped with the A3S, but, as an electrical engineer, I can say there are some problems with this that worry me. The first problem is that the power supplies are unsafe unless mounted in another enclosure as the LV terminals are exposed to touch (hence don’t comply with BS7671 wiring regulations for Low Voltage supplies if used without an enclosure - then cooling issues come into the equation). The second is that some of these supplies are so cheap you worry about the quality.

i’ve been doing some research and found for example the Power Pax or Mean Well IP rated ranges of 600w (up to 25 Amp) power supplies which do comply (e.g. Mean Well HLG-600H-24) . There are different versions (some models have tuneable voltage and current pots for example for C.V. and C.C. operation). They’re also IP rated! But they’re not cheap.

Hope this helps someone.
Post edited by jollypike on

Comments

  • Samuel PinchesSamuel Pinches Posts: 2,997Administrator
    One option is to use a standard LED power supply, and to print a cover for the terminal end. There are several designs on thingiverse. A good quality brand is MeanWell. On the wiki there is a link to a meanwell power supply that is used in the A5. This is a good option for upgrading the A3S as the bed is smaller.
  • jollypikejollypike Posts: 12Member
    edited April 2018
    Hi Samual, thanks for your input, There’s still a problem with this. Apart from the dubious quality of many cheap LED PSU’s (same with ATX PSU’s), as you say Mean Well being a good make, these psu’s often have grilles for cooling across their entire length and so are still unsafe - a paperclip or other conducting object would cause harm. Even a cover for the rear terminals probably wouldn’t make them comply with the IET regulations (BS7671 in the UK) except by being inside another enclosure (protection by enclosure).

    indeed I read an article about their use with LED’s which was indicating that even placing these out of reach (say in a loft) wasn’t acceptable as an untrained person could access the loft and come to harm. Only an enclosure was acceptable (and obviously that enclosure must be cooled or act as a heatsink).

    As an electrical engineer I’ve had this safety discussion a few times with designers LOL.
    Post edited by jollypike on
  • Samuel PinchesSamuel Pinches Posts: 2,997Administrator
    Yes, that is true, perhaps a full printable enclosure, or a large hobby box is a better idea? But as for quality, the meanwell power supplies are excellent. They are UL listed, for what that’s worth.
  • jollypikejollypike Posts: 12Member
    edited April 2018
    Hi Samuel, yes Mean Well are brilliant. I couldn’t find the model number before. Hence why I mentioned Power Pax. However I’ve found it now and updated my post - HLG-600H-24. These are quality IP rated PSU’s which are fully enclosed but they are very EXPENSIVE LOL. Still I’d always choose this over a cheap one where my safety, or my children’s, pets and house safety is at stake!

    Its the same with computer ATX PSU’s. Always buy higher power than you need so you don’t stress it, and buy quality!
    Post edited by jollypike on
  • Samuel PinchesSamuel Pinches Posts: 2,997Administrator
    edited April 2018
    They sound like an excellent option! :smile:
    If you find a good price somewhere, let me know, and we can add it to the wiki!
    Post edited by Samuel Pinches on
  • jollypikejollypike Posts: 12Member
    The best price I’ve found for Mean Well PSU’s in Europe is time.eu. In Sterling the HLG-600H-24 is still £145 including sales tax! The Power Pax 600w one is a similar price from led-supplies.com. That’s quite cheap compared to some of the PSU’s we use at work but still half the cost of the A3S (without mods).

    Personally I think I’d use a bench PSU as they can be used for all sorts of projects LOL,



  • Samuel PinchesSamuel Pinches Posts: 2,997Administrator
    edited April 2018
     Would another option be to make a small PCB board to run two cheap 240w Dell DC external brick power supplies in parallel?   Or you could add an external mosfet to the printer, so that you can use a different power supply for the heat bed, and still use the original power supply for the rest of the printer .
    Post edited by Samuel Pinches on
  • jollypikejollypike Posts: 12Member
    Good idea Samuel

    Or buy some of these super cheap iP rated power supplies (min order 5). You’ll need a few when they blow up and have a spare for a couple of friends LOL.

    https://www.alibaba.com/product-detail/Factory-outlet-600w-25A-50A-constant_60511544440.html?spm=a2700.7724838.2017115.270.22137ae8X28UG0
  • Samuel PinchesSamuel Pinches Posts: 2,997Administrator
    edited April 2018
    I have done some reading, and apparently my suggestion to run 24V switch mode power supply’s in parallel is not a good idea, as they do not share the load equally. Apparently it is better to run to 12 V power supplies in series, is that puts equal load on each power supply consistent.

    That high power LED power supply you’ve posted looks like it should work fine. But it would be nicer, if we could find a brand-name product that would give greater confidence in its reliability...👍 However if you can find one that is IP 67 rated, you could submerge it in a bucket of water, that way it could never catch fire! 😂😂😂
    Post edited by Samuel Pinches on
  • jollypikejollypike Posts: 12Member
    I’d agree Samuel, running them in series is more sensible. Or just buy a 24v psu!

    i think Mean Well is still the best choice because it will be safe and guaranteed.
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