Why should control wiring be routed separately from power wiring?

• A. To minimize costs
• B. To shorten overall ground path
• C. To minimize interference and improve safety
• D. To reduce current in the circuit

Answer: (C)

Separating control wiring from power wiring reduces the chance that disturbances from the power side will affect the control side. Power conductors carry higher currents and switching transients, which create electrical noise, voltage spikes, and magnetic fields. These can couple into the low-voltage control circuits, causing false readings, misoperations of valves or sensors, or unstable controller behavior. By routing control wiring separately, you limit this interference and keep control signals clean and reliable. It also enhances safety by reducing the potential for high-voltage arcing or contact with control conductors, and by keeping sensitive control devices isolated from the switching noise of the power system. In practice, run control cables in their own conduit or duct, and cross power lines at right angles when paths must intersect, maintaining adequate separation and, if needed, shielding.