Electronic – How to connect PCU to Stepper driver (NEMA 23)

stepper motor

  • I have bought a stepper motor, NEMA 23 (Bipolar, 4 wires, 23HS30-2804S-PG15)
  • I also have PCU 350W 48V 7.3A 115/230V (S-350-48)
  • I also have stepper driver (DM556T, Digital Stepper Driver 1.8~5.6A 20-50VDC)

(I hope it fits together..)

I want to connect it together, but:
DMT556T has connections named: V+ and GND
PCU looks like this:
PCU picture

My confusion is like an output is (I think marked) V+ and V- , ground is where I connect it from the wall and it doesn't look marked like an output.

So how should I connect these together?

I was googling like crazy and found two:

  • a) Some people connected V+ to V+ and V- to GROUND and driver
  • b) Some additionally connected on PCU from "a loop" from GROUND to V- (so ground on PCU has input from wall and at the same time is connected back on PCU on V-)

I saw so many videos and saw these approaches I believe – but none of them explained why and when it is applicable and what drives this decision?

Best Answer

The A/C (input) side of your supply is Earth, Neutral, and Line. The D/C (output) side is V+ and V-. For the D/C side you usually use the V- as "ground". You could also use V+ as your "ground" to get a -48 V supply.

This type of supply is "isolated" meaning there is not normally a connection between V- and Earth. You can connect them together, if you need your DC ground to be common with Earth.

The decision comes down to whether or not you want your DC ground to be tied to Earth potential.

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