Electrical Components & Controller Programming Flashcards

A Wi-Fi-enabled smart irrigation controller loses its internet connection. How will it handle scheduled irrigation?

Answer: The controller continues running its locally stored schedule until the connection is restored and updates can be downloaded

Smart controllers store their current schedule locally and continue operating on that schedule during internet outages. Once connectivity is restored, the controller downloads any updated weather data or schedule changes from the cloud.

A controller's display shows an 'ERR' or fault code on a specific zone. After verifying the zone wiring is intact, what component inside the controller is most likely responsible?

Answer: The triac (solid-state relay) that switches power to that specific zone output

Each zone output on a controller is typically controlled by a triac (solid-state relay). If the triac has failed (often from a surge or short circuit on the zone wiring), it cannot switch 24 VAC to the zone, triggering a fault code even though the wiring and solenoid are fine.

What is a 'program' in the context of a multi-program irrigation controller?

Answer: An independent watering schedule with its own set of assigned zones, run times, start times, and watering days

A program (typically labeled A, B, C on the controller) is an independent watering schedule. Different zones can be assigned to different programs with separate watering days and start times, allowing turf, shrubs, and drip zones to operate on different schedules.

A soil moisture sensor is connected to an irrigation controller. When the soil moisture level is above the setpoint, the controller will:

Answer: Skip or suspend scheduled irrigation cycles until the soil moisture drops below the setpoint

A soil moisture sensor overrides the controller's scheduled watering when soil moisture is adequate. When the sensor indicates moisture above the threshold, scheduled irrigation is suspended. When moisture drops below the threshold, irrigation resumes on the next scheduled cycle.

When replacing a controller battery, what is its primary function in most modern irrigation controllers?

Answer: To maintain the real-time clock (date and time) during power outages so the schedule runs at the correct times

In modern controllers with non-volatile memory, the battery's primary function is maintaining the real-time clock during power outages. The programming is stored in non-volatile memory (which doesn't need power), but the clock needs continuous power to keep accurate time.

A decoder-based two-wire irrigation system requires what additional component at each valve location that a conventional multi-wire system does not?

Answer: A field decoder module that receives signals from the two-wire path and activates the specific solenoid valve

In a two-wire decoder system, each valve (or group of valves) has a field decoder that receives encoded signals from the controller via the two-wire communication path. The decoder interprets its unique address and activates the corresponding solenoid when signaled.