CTSP Electrical Hazards and Utility Line Safety 2 — Questions and Answers
Question 1: Before beginning tree work in proximity to utility lines, a tree care company's most important first step is to:
- Post warning signs at the work site perimeter
- Contact the utility company to coordinate the work and establish safe procedures (Correct answer)
- Inspect all PPE for the crew
- Notify the local fire department
Correct answer: Contact the utility company to coordinate the work and establish safe procedures
Coordinating with the utility company before work begins ensures lines can be de-energized, insulated, or that proper approach distances are established before any crew member enters the work zone.
Question 2: When a tree limb falls onto an energized power line, what is the FIRST action a ground worker should take?
- Call 911 and warn bystanders to stay well back from the area (Correct answer)
- Cut the limb free using a fiberglass-handled tool
- Pull the limb away using a rigging rope already attached to it
- Approach carefully to assess whether the line is still energized
Correct answer: Call 911 and warn bystanders to stay well back from the area
The immediate priority is life safety — alerting emergency services and keeping all personnel clear prevents additional injuries from step potential and contact hazards.
Question 3: The 'Limited Approach Boundary' in electrical safety is defined as:
- The distance within which an unqualified person faces a shock hazard and may not enter without an escort (Correct answer)
- The maximum chainsaw bar length permitted near distribution lines
- The minimum climb height allowed above energized conductors
- The boundary established by the utility for public access during outages
Correct answer: The distance within which an unqualified person faces a shock hazard and may not enter without an escort
The Limited Approach Boundary marks the point at which an unqualified person is at risk of shock and must not cross without a qualified escort or specific authorization.
Question 4: For energized lines rated above 50kV, how much additional minimum approach distance must unqualified workers add for every 10kV above 50kV?
- 1 inch (2.5 cm)
- 4 inches (10 cm) (Correct answer)
- 6 inches (15 cm)
- 12 inches (30 cm)
Correct answer: 4 inches (10 cm)
Per OSHA 1910.333, unqualified worker minimum approach distances increase by 4 inches for each additional 10kV (or fraction thereof) above 50kV.
Question 5: Which personal protective equipment provides primary electrical isolation for qualified line-clearance arborists working near energized conductors?
- Class E hard hat alone
- Rubber insulating gloves with leather protectors and other rubber insulating equipment (Correct answer)
- Fiberglass-handled tools used without gloves
- Fire-resistant (FR) clothing as the sole protection
Correct answer: Rubber insulating gloves with leather protectors and other rubber insulating equipment
Rubber insulating gloves (with leather protector gloves over them) and other rubber insulating equipment provide the primary barrier between the worker and an energized conductor.
Question 6: In aerial lift operations, 'two-blocking' refers to:
- Placing two wooden wedges to stabilize a cut section
- The load block or hook contacting the boom tip, which can cause catastrophic rigging failure (Correct answer)
- A procedure requiring two workers to visually clear power line proximity
- Dual blocking of outrigger pads for stability on soft ground
Correct answer: The load block or hook contacting the boom tip, which can cause catastrophic rigging failure
Two-blocking occurs when the hook block contacts the boom head or tip sheave, placing extreme stress on the line and potentially causing the hoist rope or load to fail.
Question 7: ANSI A300 Part 7 (Integrated Vegetation Management) is most relevant to electrical utility tree work because it:
- Sets minimum electrical rating requirements for arborist equipment
- Establishes best management practices for utility right-of-way vegetation management (Correct answer)
- Requires all arborists to obtain an electrical contractor license
- Mandates rubber insulating gloves for all outdoor tree work
Correct answer: Establishes best management practices for utility right-of-way vegetation management
ANSI A300 Part 7 provides industry best management practices (BMPs) for integrated vegetation management programs, which are central to utility right-of-way and line-clearance work.
CTSP Electrical Hazards and Utility Line Safety 2
Before beginning tree work in proximity to utility lines, a tree care company's most important first step is to: