NCCCO Power Line Hazard Identification and Safety Procedures 2

Question 1

What is the minimum safe approach distance for a crane near power lines up to 350 kV?

Accepted Answer

20 feet

Answer

OSHA requires a minimum 20-foot clearance from power lines up to 350 kV for cranes and their loads. For higher voltages, greater distances are required.

Question 2

Before beginning crane work near power lines, what must the employer do?

Accepted Answer

Identify all power lines in the work area, determine voltages, establish safe approach distances, and create a work plan

Answer

OSHA requires employers to identify power lines, determine voltages, establish and communicate minimum approach distances, and create a specific plan for safe operation near energized lines.

Question 3

What is an 'encroachment' or 'trigger' distance in relation to power lines?

Accepted Answer

A predetermined distance from the power line that triggers additional safety measures (dedicated spotter, slower operations) before reaching the minimum approach distance

Answer

The encroachment distance is a buffer zone beyond the minimum approach distance. When any part of the crane enters this zone, additional safety measures activate (dedicated spotter, reduced speed).

Question 4

If a crane contacts a power line and the operator cannot break free, what should they do?

Accepted Answer

Stay in the cab, warn everyone to stay away, and call for emergency help to de-energize the line

Answer

The operator is safest inside the cab. If they exit while the crane is energized, stepping onto the ground while touching the crane creates a path for current through their body.

Question 5

What is 'step potential' and why is it dangerous near an energized crane?

Accepted Answer

Voltage difference between two points on the ground near an energized source — current flows through your body between your feet

Answer

When current flows through the ground from an energized crane, voltage decreases with distance. The voltage difference between your two feet can drive current through your body — potentially lethal.

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO Power Line Hazard Identification and Safety Procedures 2