Well dressed = less exposedWire dress, i.e. how and where you route your wires, can have a profound effect on the performance of your control system. Electronics can be quite sensitive to fast, high voltage and current pulses borne on wires and the resultant radio waves generated by such pulses. Symptoms include erratic behaviour or simply locking up.
All such nasties are generally called electrical noise or EMI. EMI is most commonly generated by any device that switches high currents on and off very rapidly, especially if there is some kind of inductance (coil) in the circuit. Typical sources of EMI therefore include motors (especially ones with brushes), contactors, arc welders, variable frequency drives and solenoids, but in general included anything where high voltage or current is switched.
To reduce the risk of EMI upsetting your controllers, keep all high power wiring away from the electronics. Keep the input wiring of your controller well away from the output wiring and any high power circuits. Make sure no potentially noisy wires are routed close to the controller electronics.
So dress those wires properly and reduce your exposure to EMI!