I'll mention this because Jonathan maybe didn't see you had 50V drives but these 3nm will be running slightly less than there ideal voltage.?

Because you have 50V Max drives then you'll need to run these motors with no more than absolute Max 48v and even thats on the high side. This is because the motors will produce current (back EMF) when de-accellerating which gets passed backdown thru the drives to the PSU, if the psu can't absorb this current then some can feed back at a much higher rate than 50v and damage the drives. sometimes esp with linear regulated type PSU's it can trip them out as they try to protect there circuits, thats why unregulated supplys are prefered.

So to be on the safeside you really need to be less than 48V or use a unregulated toroidal transformer supply which can handel the EMF much better.

Really if your looking to run 3nm and esp 4nm to there full potential they need much more voltage than 48V, 65/70v is much better for 3nm and 70/75V for 4nm so then you need drives that can handle 80V.

This is why I always say buy the drives/motors/psu after you have at least designed the machine. This way you can size them to suit.!

It's very common thou for eager new folks to rush out and buy drives/motors etc first it's also silly common for them to buy or be sold the wrong size PSU which doesn't match the drives or motors.!! I see far to meny 36V supplys bought with 50V drives and 3nm motors which want 60+ V to work to full potential. .