Stupid Question?

[exurbia]

I hope this isn't a stupid question. Feel free to have a go at me if it is....

I have two Meanwell RS150-48 power supplies,

Q. Can I connect the outputs in series to give me plus and minus 48Vdc the same way I would with two single winding transformers?

Thanx in advance.

 

[DF96]

Are the outputs isolated?

 

[exurbia]

do you mean isolated from the earth or from each other?

 

[exurbia]

Not sure if this helps.
when I connect across the + and - signs I get 49 volts dc
If I connect either of the outputs to earth the voltage falls from approx 7v to zero after a few seconds.

 

[exurbia]

I have looked at meanwell site and it show this as a single output does this mean 48V or 24 0 24?
I'm a bit out of my depth here.....

 

[DF96]

do you mean isolated from the earth or from each other?

Isolated from earth. I assume that two quite separate PSU boxes are otherwise isolated from each other.

If I connect either of the outputs to earth the voltage falls from approx 7v to zero after a few seconds.

This suggests it is really a -24 0 +24 supply. However, which voltage falls? You need to remember that every voltage is between two points, but usually we measure voltage from earth. The output you earth must be at 0V from earth. So are you saying that connecting one terminal to earth makes the other terminal drop its voltage too?

I have looked at meanwell site and it show this as a single output does this mean 48V or 24 0 24?

'Single output' may mean 0-48V supply.

I think you need to contact them and ask.

 

[DF96]

The data sheet here appears to show an isolated output, with just a capacitor from -ve to ground. However, the text does not say that the output is isolated.

 

[Ketje]

Looks like the output is floating, if not the C to ground is useless.
Best to put a diode (1N4007) in blocking direction across each supply.
Mona

 

[biggerdog]

I did it with a pair of RS-25-12's for use with op amps, no problems encountered so far.

 

[jitter]

I just had a closer look at my RS-75-12 and this one has an output that is completely isolated from earth. Its block diagram is exactly the same as your RS-150-48.

Not sure if this helps.
when I connect across the + and - signs I get 49 volts dc
If I connect either of the outputs to earth the voltage falls from approx 7v to zero after a few seconds.

By "connecting across" in the last sentence you mean put a meter across it and not short circuit it, right?

 

[exurbia]

Thanks everyone for your input. I decided on the suck it and see method, hooked em up as intended and stood back. Nothing happened and I now have a 48-0-48 supply.
As this approach seems quite usable I will now buy the nice cheap meanwell supplies.
Anyway they are now for sale with the Nu Force monos...There wasn't enough grunt for my Cold Amp units.