NCCCO Hazard Identification and Power Line Safety 1 — Questions and Answers
Question 1: Under OSHA 1926.1408, what is the minimum required clearance when operating a crane near an energized power line rated at 50 kV or less?
- 10 feet (Correct answer)
- 6 feet
- 15 feet
- 20 feet
Correct answer: 10 feet
OSHA 1926.1408 Table A specifies a minimum 10-foot clearance for lines up to 50 kV unless the line is de-energized and grounded, or an insulating link is used.
OSHA 1926.1408 Table A establishes that for power lines up to 50 kV, the default minimum clearance is 10 feet. For voltages above 50 kV, add 0.4 inch per kV above 50 kV. These clearances apply to all crane parts — boom, load line, load, and counterweight — at all times during operations.
Question 2: Before any crane operation near power lines, the employer must attempt to determine the voltage of the lines. If the voltage cannot be determined, what clearance applies?
- 10 feet minimum until the utility confirms the voltage (Correct answer)
- The maximum clearance in Table A (45 feet for 750 kV)
- Zero clearance if insulated boom covers are installed
- 5 feet if a spotter is present
Correct answer: 10 feet minimum until the utility confirms the voltage
OSHA 1926.1408(b) states that if the voltage cannot be determined, the minimum 10-foot clearance in Table A applies until the utility owner confirms the actual voltage.
Per OSHA 1926.1408(b)(1), when the operator cannot determine the line voltage, the 10-foot minimum applies as a baseline default. The employer must contact the utility owner for actual voltage information and, where feasible, have the utility de-energize or relocate the line before work begins.
Question 3: Which hazard recognition step is required when a crane must work within the Table A distances of a power line?
- Contact the utility owner and obtain written confirmation of voltage and whether de-energizing is feasible (Correct answer)
- Install a warning flag on the boom tip and proceed
- Post a sign at the site entrance noting the power line
- Reduce swing speed to less than 2 RPM
Correct answer: Contact the utility owner and obtain written confirmation of voltage and whether de-energizing is feasible
OSHA 1926.1407 requires the employer to contact the utility before encroaching on Table A distances to discuss de-energizing, insulating, or relocating the line.
OSHA 1926.1407 mandates that before any operation near power lines, the employer determines if any part of the crane or load could enter the Table A zone. If so, the utility must be contacted to de-energize the lines, install insulating sleeves, or relocate them. Until those controls are in place, cranes cannot operate within Table A distances.
Question 4: If a crane boom accidentally contacts a power line and the crane becomes energized, what should bystanders on the ground do?
- Stay away and not touch the crane or any grounded object near it (Correct answer)
- Immediately grab the outrigger pads to stabilize the crane
- Run toward the crane to help the operator exit
- Pour water on the contact point to quench the arc
Correct answer: Stay away and not touch the crane or any grounded object near it
When a crane contacts a power line, ground current can radiate outward. Anyone touching the crane or standing close can complete a circuit and be electrocuted. Bystanders must stay clear until the utility cuts power.
An energized crane creates a step potential gradient in the ground around it. Anyone within that zone can be killed by current flowing through their body between two points at different voltage. Bystanders must not touch the crane, load line, or any equipment in contact with the ground near the crane. Emergency calls should be made from a safe distance.
Question 5: Under OSHA 1926 Subpart CC, which person is responsible for identifying power line hazards before crane setup begins?
- The employer or competent person conducting the hazard assessment (Correct answer)
- The signal person assigned to the lift
- The utility company's field representative only
- The crane manufacturer's field service technician
Correct answer: The employer or competent person conducting the hazard assessment
OSHA 1926.1402 requires the employer to assess the site for power line hazards before equipment is assembled or used. A competent person typically conducts this assessment.
Per OSHA 1926.1402(a), before erecting or using equipment, the employer must determine if any part of the equipment or load could be within the Table A distances of a power line during operations. This pre-assembly survey is the employer's responsibility and is typically delegated to a competent person who documents the findings.
Question 6: A spotter (dedicated observer) is used during operations near power lines. Which of the following is a correct requirement for the spotter?
- The spotter must be positioned to clearly see the crane and power line and be in direct communication with the operator at all times (Correct answer)
- The spotter may also serve as the signal person for the lift simultaneously
- The spotter must stand between the crane and the power line
- The spotter's role is optional if the operator has a line-of-sight view
Correct answer: The spotter must be positioned to clearly see the crane and power line and be in direct communication with the operator at all times
OSHA 1926.1409 requires the dedicated spotter to maintain continuous observation of the crane's proximity to the line and communicate in real time with the operator.
Under OSHA 1926.1409, the dedicated spotter must: (1) be positioned to see the clearance between the crane and the line, (2) give timely warning to the operator, and (3) not be assigned any other duties while serving as spotter. Combining the spotter and signal person roles is prohibited because split attention can result in a strike.
NCCCO Hazard Identification and Power Line Safety 1
Under OSHA 1926.1408, what is the minimum required clearance when operating a crane near an energized power line rated at 50 kV or less?