Can I connect two motors in parallel to a single driver?
You can, but the currents add up: the sum of the two motors' continuous currents under load must not exceed the driver's rating. This limit is 15 A for the KS250 and 30 A for the PT500. Since the pulses of both motors will arrive at the same time at start, the total peak must also fit into the 45 A / 5 s or 40 A / 15 s window.
Points to watch when connecting in parallel:
- Currents add up. Measure each motor's current under load separately and add them. The total must not exceed 15 A on the KS250 and 30 A on the PT500.
- Starting pulses overlap. If two motors start at the same time the pulse doubles as well. Using a ramp (built in on the KS250, the RMP pot on the PT500) brings this total down to typically 2-4 times the nominal current.
- The motors cannot move independently. Both run in the same direction at the same speed. If separate control is needed, use two separate drivers.
- Load imbalance. If the motors have different loads one draws more current than the other; the strained motor heats up first.
- AntiSwitch gets confused. Current sensing sees the total current. When one motor reaches its end stop the total current rises and both motors stop together. If the end points of the motors matter separately, parallel connection is not suitable.
In the wiring, run a separate arm to each motor and choose the cross sections according to their own currents; the common supply arm must be sized for the total current.
The full topic: DC Motor Driver Selection Guide