MEANWELL RSP PSUs - Not working on startup, work fine on restart (2)

Thread Starter


Joined Apr 18, 2024

I am having a problem where our power supplies sometimes don't work on startup. This condition presents on machine startup after the machines have been turned off 2-3 days. Here is the sequence of events:
  1. Machine is turned off.
  2. 2-3 days pass.
  3. Machine is turned on. Note: we run the power supplies using the remote on/off signal. This signal allows us to turn on the machine and provide AC to the power supply, and then selectively turn on the DC output.
  4. Remote ON, power supply does not provide any power. PSU is receiving AC because status light is on.
  5. Turn off primary power to machine for at least 30 seconds.
  6. Restart.
  7. Remote ON, power supply works fine.

PSU model: RSP-750-24. Note, this only occurs after machines have been in service 3+ months, where power is cycled (AC applied) once per day. Remote ON circuits work fine, no major visible corrosion on units.
PSUs are run on CC mode, with voltage left to swing to max 24 V output.

Any ideas? Anyone encounter this issue before?
I have 100% seen this issue before except on the RSP-2000-48. I reported the issue to our distributor in Jan 2023 who sent it up to Meanwell and was assured that it was an isolated issue. I received an order of 100 units of which 30 were red light out of the box and many of the others had the issue you are describing. Following this my distributor forced me via the courts to buy the remaining 600 units I had a blanket P.O. for. I believe they knew there was an issue but once they got them off their dock it became a warranty issue and did not affect their sales.

Anyway, 14 months after my initial report, I get an email from my supplier stating that there was a "software" issue with the 600 units that they sent us and they would like to pick them up to be "corrected" and returned at some unknown point in the future. Why would I buy 600 power supplies ($168,000) to keep them around for 14 months?? We used the units that seemed to pass initial testing only to later learn that the problems were intermittent and would come and go.

The issue could not be software and in my opinion was a lie. I believe these were COVID era builds with subpar or substitute components and that did not go thru a UL test update. I believe they knowingly let us use these POS in our products. I have shipped back the remaining 230 that I had direct to Meanwell for "the fix" The first 26 that I got back has worse or the same problem.

If anyone else has seen these problems I would like to hear your story, it may not be on the scale that we have experience but I believe there is a pattern that would have been easy to disguise shipping them to people buying one or two at a time.
Happy to share my contact information.

Moderator edit: New thread created from this.