Certification Examination Practice

Illinois Transmission Line Technician Certification Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of a transmission line?
• To supply power to residential homes
• To distribute low-voltage electricity
• To transfer high-voltage bulk power over long distances
• To step down voltage for industrial use

Rationale: Transmission lines carry high-voltage power across long

distances before distribution.

• OSHA requires fall protection at what minimum height for transmission

tower work? 1 / 4

• 2 feet
• 4 feet
• 6 feet
• 15 feet

Rationale: OSHA mandates fall protection at 6 ft for construction activities,

including transmission work.

• The most common material used for overhead transmission conductors

is:

• Copper
• Aluminum Conductor Steel Reinforced (ACSR)
• Brass
• Annealed steel

Rationale: ACSR provides strength from steel and conductivity from

aluminum.

• Which device protects a line from lightning surges?
• Recloser
• Sectionalizer
• Surge arrester
• PT

Rationale: Lightning/surge arresters divert overvoltage spikes to ground. 2 / 4

• What is the main purpose of grounding transmission structures?
• Aesthetic appearance
• Provide a low-resistance path for fault current
• Reduce radio noise only
• Prevent conductor galloping

Rationale: Grounding ensures faults quickly travel to earth, clearing

through system protection.

6. The minimum approach distance (MAD) is based on:

• Weather conditions only
• System voltage and worker qualification
• Worker age
• Conductor diameter

Rationale: MAD is determined by voltage level and whether the worker is

qualified.

7. A transmission line operating at 345 kV is classified as:

• Distribution
• Sub-transmission
• High voltage transmission
• Low voltage 3 / 4

Rationale: Anything above ~230 kV is considered high-voltage transmission

in the U.S.

• What is the primary hazard when climbing a steel lattice tower?
• Static electricity
• Fall hazard
• Arc flash
• Wildlife

Rationale: Fall hazard is the primary risk during tower climbing.

• Which PPE is mandatory when working near energized lines?
• Hard hat only
• Hard hat, safety glasses, FR clothing, and gloves
• Safety vest only
• Steel toe boots only

Rationale: Full PPE is required to mitigate multiple hazards.

• What instrument measures current in transmission lines?
• Voltmeter
• Ammeter
• Thermometer
• / 4