Meanwell SPV-300-24 Problems

  • So I have myself a problem which I am hoping someone can resolve for me - possibly by saying no you are just an idiot…...

    I bought myself a Meanwell SPV-300-24 power supply which arrived yesterday. I wired it up with an old PC power cable which I have since confirmed is fine by connecting it up to a 12v power supply I had lying idol. The cable itself is definitely wired in correctly (L,N,E) and I have confirmed that a connection has been made in each case with a multi-meter (not while plugged in, obviously). This is the first power supply I have owned that doesn't have a switch to select either 120v or 240v. I am in the UK so use 240v (I realise officially 230v) but the unit is designed to automatically deal with either or so I believe.

    The problem is when I turn the Meanwell on not a lot happens. No noise, no fan activity, there isn't a power on LED unfortunately which in this case would help. However, when plugged in I do record a small voltage of 0.8v from the V+ V- terminals.

    Essentially what I am looking to find out is whether I have bought a dud or I'm missing something and I'm the dud!

    Any help on this matter would be most gratefully received.

  • administrators

    Is the output connected to the Duet? If it is, are you sure you have the + and - output terminals connected the right way round to the Duet?

    If is isn't connected to the Duet, are you sure you are measuring the output at the correct terminals? That PSU has + and - remote control terminals too.

  • I have my Duet already to go but I haven't yet connected it. I wanted to check that the PSU was working correctly before joining it up. I have been checking the voltage using each combination of the V+ and V- terminals and that is where I get the 0.8v reading. The other two terminals are marked RC and PV which I am a little unsure about.

  • administrators

    The RC input is for external power on/off, but the datasheet implies (but doesn't actually state) that if left unconnected then the power will be on. You could try connecting RC+ to RC- in case it makes any difference.

    The PV terminals are for controlling the voltage. Unfortunately the datasheet doesn't say what happens if you leave them unconnected. You may need to apply 5V to them to make the PSU work.

  • Thanks very much for both of your replies.

    I see what you are saying and it does make sense to me but I'm a little concerned about trying anything that may mean I can't return it if that's what it comes to. Just to confirm though that although there are 2xV+ and 2xV- there is only 1xRC and 1xPV if that makes things any clearer?

    Perhaps I have simply bought the wrong thing? Any suggestions for viable alternatives would be appreciated.

  • Ok, this gets stranger.

    Attaching a 24v fan between +V and -V,
    External 5v supply connected to PV (+5v red wire) and -V (GND white wire).

    Turning on 5v power and then PSU and both the 24v fan and the PSU fan rotate as expected but only for a few seconds. Turning off both the 5v and the PSU then turning on only the PSU and again both the 24v fan and internal fan rotate but this time for about 10 seconds and then stop!

    I'm not entirely sure why or what this means…...............

  • administrators

    It may mean that the PSU is faulty and some sort of overload or overheat detection is triggering.

  • Yes I am beginning to wonder. Sadly a new Duet set up without a PSU is not much good to anyone. How would this sound to you as a suitable replacement?

  • administrators

    That looks suitable (assuming 350W is sufficient for your machine), and it doesn't have the complication of remote control.

  • Thanks for the reply. Yes I worked out about 280.5w

    Steppers (rated current x rated voltage + 50%) = 2 x 2.8 + 2.8 = 8.4 x 5 steppers = 42w
    Duet = 5w
    Heater cartridge = 40w x 2 cartridges = 80w
    Fans = 3w x 2 fans = 6w
    Panel Due = 3.5w
    Heated Bed (4 ohm of resistance according to my multi-meter at least) = 144w

    I thought less complication might be a good thing!

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