Should I twist DC power and ground wires from a power supply?
Twisting wires reduces the magnetic loop area of the wires, this has two implications:
- Reduced susceptibility to noise from magnetic fields, with twisted wires an a smaller magnetic loop area, external magnetic fields will induce less current in the loop made by the wires than straight cables.
- Reduced magnetic radiation from loads that are switching. A magnetic loop is an antenna, switching loads and changing currents cause the antenna to radiate magnetic radiation, which can cause noise in other devices.
Generally its a good idea to twist the wires and reduce the radiation and susceptibility to noise.
I can't think of any reason why you wouldn't do this, on all of my prototypes/products I make sure the wires are twisted.
It would reduced radiated noise. No specific reason to really avoid it since the only real reasons are reduced heat dissipation and overkinking the cable which shouldn't happen if you do it properly.
It would also reduce noise that is coupled to the lines that enters the power supply (by ensuring the noise is picked up "identically" on both lines), but that barely matters at all for something like the kind of power supply you probably have.