[Jkountz]

Im looking for help in choosing the proper power supply for my proposed setup.
I have two steppers Nema 34 900oz.in driving the X slaved together.
I have one Nema 23 500oz.in on the Y and on the Z.
The total amps for all 4 motors is 22, 6A each for the 34's and 5A each for the 23's. So I took the usual 67% of this and it comes to 14.75 A. Ok so now I know I need at least a 15amp supply. Right?
Moving on. The Inductance for the Nema 34's is 3.3. For the Nema 23's its 2.5. So the max V for the 23's is 50.59. For the 34's its 58.13V. I arrived at this figure by multiplying the Sq root of the inductance by 32.
Soooooooooo.
The power supply Im looking at is a 50VDC 20A unregulated.
My worry here is that since the max V for the 23's is 50.59 that this might me too close for comfort? I would just go to a 48VDC supply but I cant seem to find one with 15A or more.
Suggestions or comments? Am I going about this right?

Thanks!!

Heres a link to the specific power supply Im looking at
http://www.kelinginc.net/KL-5020.pdf

[ger21]

The difference between 48 and 50V shouldn't really make any difference. The motor will just run a little hotter, but I wouldn't think much at all.

[James Newton]

I like lead acid batteries. Pretty much darn near unlimited current. Then you just have to keep up with the current drain by recharging the batteries. The 15 amps is peak... there are lots of times when the motors aren't moving or aren't moving at full speed. So a 48 volt, few amp battery charger will do just fine. Not sure if that helps, but 48 volt chargers are certainly available.

[H500]

50v won't hurt the motors. The inductance equation gives 42v for my motors, but during testing, I've gone as high as 60v.

Although it's good to have a big power supply, I doubt that you will need more than 5 amps for all 4 motors. Even at 60v, my 4 amp motor will not draw more than 1 amp peak under load.