CIT - Certified Irrigation Technician Electrical Systems and Wiring Questions and Answers

Question 1

A technician is installing a low-voltage irrigation system. According to the National Electrical Code (NEC), what is the minimum required burial depth for low-voltage landscape wiring (under 30 volts)?

Accepted Answer

6 inches

Answer

The National Electrical Code (NEC) Section 300.5(A) specifies that low-voltage landscape lighting and irrigation wires (under 30 volts) must be buried at a minimum depth of 6 inches. This depth helps protect the wires from accidental damage from activities like aeration or light digging.

Question 2

When making a wire splice in an irrigation valve box, which of the following is the most critical feature of the connectors used?

Accepted Answer

They must be waterproof and approved for direct burial.

Answer

Valve boxes are wet, damp environments, and splices are susceptible to corrosion, which can lead to electrical failure. Using waterproof connectors, often filled with silicone or grease, is essential to protect the copper connection from moisture and ensure the long-term reliability of the system.

Question 3

An irrigation system has a total load of 1.5 amps on a 24-volt circuit. To properly size the transformer, a technician should select a transformer with a VA (Volt-Amps) rating that is:

Accepted Answer

Slightly greater than 36 VA

Answer

To calculate the required VA, multiply the voltage by the amperage (24V x 1.5A = 36 VA). However, it is a best practice to size the transformer slightly larger than the calculated load to avoid overheating and to accommodate potential future additions or voltage drops. Operating a transformer at its maximum capacity can shorten its lifespan.

Question 4

A technician measures the resistance (ohms) across the two wires leading to a normally closed solenoid and gets a reading of 'OL' or infinity. What is the most likely problem?

Accepted Answer

A broken wire or a bad splice.

Answer

An 'OL' (Over Limit) or infinite resistance reading on a multimeter indicates an open circuit. This means there is a break in the electrical path. In an irrigation system, this is most commonly caused by a completely broken wire, a disconnected wire at the solenoid, or a failed wire splice somewhere along the path.

Question 5

Which type of wire is specifically designed and rated for direct burial in landscape and irrigation applications?

Accepted Answer

UF-B

Answer

UF-B (Underground Feeder) cable is the correct choice as it is designed for direct burial in the ground without the need for conduit. Its outer jacket is water, fungus, and corrosion resistant, providing the necessary protection for underground applications. THHN and Romex are not rated for direct burial.

CIT - Certified Irrigation Technician Practice Test

CIT - Certified Irrigation Technician Practice Test

CIT - Certified Irrigation Technician Electrical Systems and Wiring Questions and Answers