I have a project using a Raspberry Pi and four FadeCandies. It is powered by 4 x Mean Well RS-150-5 power supplies. I know that i need to keep the +ive circuit for each power supply separate while making the -ive common, to all power supplies as well as the LED -ive.
My question is: Each power supply has two +ive and two -ive terminals, with a voltage fine adjustment on one of the +ive terminals. Each power supply has two feed out wire pairs. Can I connect the two +ive terminals on the same power supply together (through power injection out in the project), or should I connect both positive wires to the same terminal? The other option is to ensure that each terminal has it’s own circuit to supply, not just each power supply. This option would be significantly more difficult to achieve.
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Hi Phillip
Short answer for both paragraphs is Yes.
Please read on:
This is a 5V,26A single supply. I think the duplication of +and - terminals is for connection conveniences you don’t have too many wires stacked up on the same terminal. I think the 2 positives and the 2 negatives are internally connected together,+ to + and - to -. A continuity check will confirm this. The small range voltage adjustment will affect both terminal sets (look up data sheet on MeanWell web site).
DO NOT connect power supplies together in parallel. This is normally done for redundancy purposes. When required this is done via schottky diodes (big ones) where 2 or maybe 3 supplies are connected in parallel. The voltages need to be carefully set so each supply picks up an equal share of the load. EACH power supply should be capable of supplying the total load so in the case of a power supply failure you would have a HOT standby with a no-break continuation of function.
My bench supply is a dual (tracking and independent) supply and I sometimes connect in parallel via diodes when I need a bit more current than the 3 Amp capability of the independent supplies. But I try to avoid this unless absolutely necessary.
Cheers Bob
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Thanks Bob. I was hoping this was the case, but I couldn’t be certain from the information I could find. The continuity check confirmed it too. One less issue to deal with in the project. Thanks again.
Phil
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Glad I/we could be of assistance. If you don’t ask you will never find out,
Cheers Bob
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on each supply they are duplicates unless other wise stated .in most cases check and look at the front panel you will see a short black line darker than the others between the output connections on the voltage label…
if the they are are multi tapped…thus different voltage levels. there will be dividers and different voltages written above the terminals…if you see 3 positives together with only a single output voltage supply then they are duplicate the all came from the same rail for example…there is not 3x 12volt separate transformer windings generally unless other wise stated by the operators manual…which you will find on the web …just brows the model or part number and then a space and type “specs” an if in most cases you will see manufacturer threads and spec sheets which will tell you about your supply.
(This reply has been sitting as a draft for months. I’ll post it just update.) Thanks Brian. There doesn’t seem to be any sort of black line on the labelling for the outputs. What had me uncertain was that I could remember reading somewhere that the voltage adjustment on these power supplies only affected one of the outputs, which I considered meant that they were managed separately. However the two positive terminals showed continuity with the multimeter, as Bob said that demonstrates that they come from a common rail.
