Which of the following reflects best practice for separate paths in an irrigation installation?

• A. Run power and low-voltage control wires in the same trench to save digging
• B. Separate the control wiring from power wiring to reduce interference and safety risks
• C. Use a single shared trench for aesthetic reasons
• D. Co-locate wiring under sprinkler heads for short lengths

Answer: (D)

The main idea here is to minimize interference and safety risks by keeping electrical power wiring separate from low-voltage control wiring in an irrigation installation. Running control wiring in its own trench or conduit, spaced apart from power conductors, reduces electrical noise that can cause valve misoperation and lowers the chance of a fault from one circuit affecting the other. It also simplifies troubleshooting and meets common safety expectations.

Putting power and control wires in the same trench invites interference and potential safety hazards, so that setup is not recommended. Using a single shared trench for aesthetics or convenience undermines separation and can complicate maintenance or fault isolation. Co-locating wiring under sprinkler heads—even briefly—exposes conductors to moisture, vibration, and maintenance damage, and it makes individual circuit repairs harder.

So, the best practice is to keep control wiring separate from power wiring, typically in distinct trenches or conduits, with clear separation to maintain reliability and safety.