Hi both,

Thanks for the responses. I'm not going to pretend that I'm not a little confused, been so out of my depth on this project, so please bare with me.

For the SMPS which drives the 4 DM542Ts, the drivers will most likely be running at 1.36 amps (RMS), not really sure if I'm supposed to go by RMS or peak but that's another question. I read somewhere that if micro stepping you should go by RMS?

So (theoretically) we have 4 drivers running at 1.36 amps = 5.44 amps

Now I just need to work out the volts. Correct me if I'm wrong but it would not be a good idea to run at 48V on the PSU? Someone mentioned this to me before as it's very close to the 50V limit of the drivers. As such, what would be a safe voltage to run the PSU at? Once I have that number I can do the calculation for power and work out the MCB for these drivers.

Once I've got this correct, I'll move onto the bigger drivers.