Hi everyone,
I blindly use twisted pair cables for power lines. I twist Power and Return cables. Also, I always twist differential signal cables. For example; Tx+ and Tx- in RS422..

I don't know the benefits. Can someone clarify when do we need to use twisted cables.

 

Take a transformer changes in one coil will be inducted in the other one but phase shifted (180 degree)
twisted wires behave the same.
pulses are a change and inducted in the other wire but with Pi radians shifted hence they eliminated.

that's why we use twisted pairs but the impedance is effected hence maximum transmission frequency limited by cable quality.
Picbuster

 

In the case of high power cables there is a cancellation effect of radiated energy (EMI/RFI) when the conductors are twisted together.
Max.

 

It can have these effects:
Cancel radiated energy from the wires.
Cancel noise pickup in the wires from EMI sources.
Provide a constant cable characteristic impedance.