If I switch from 12V to a 24V system, what changes on the driver and cabling side?
For the same mechanical power, doubling the voltage roughly halves the current. This cuts transmission loss to a quarter, reduces the required cable cross-section and eases the voltage drop budget: a 3% drop is 0.36 V at 12V but 0.72 V at 24V. On the driver side the KS250 15 A and PT500 30 A limits do not change.
The gain from moving to 24V appears in the current. When the current halves at the same power:
- Because transmission loss is P = I² x R, cable and connection losses fall to roughly a quarter.
- You can go a longer distance with the same cable cross-section. In low-voltage systems the cross-section is most often determined not by current-carrying capacity but by voltage drop; at 12V a 3% drop is only 0.36 V, whereas at 24V you have a budget of 0.72 V.
- The fuse rating also falls with the current; the general rule is 125-150% of the continuous current.
What does not change on the driver side:
- The KS250 and PT500 already work at 12/24V, so you do not need to change the module.
- The current limits stay the same: KS250 15 A continuous / 45 A peak (5 s), PT500 30 A continuous / 40 A max (15 s).
Preparing for the change: the motors must be rated for 24V, the input signal levels must suit the new voltage, and the AntiSwitch thresholds (the A1/A2 pots on the PT500) must be recalibrated. In the calculation, the resistivity of copper is taken as approximately 0.0175 Ω·mm²/m.
Full topic: DC Motor Driver Selection Guide