United States
Hong KongCrane power line clearances
Twenty feet is the default minimum clearance for crane assembly near lines up to 350 kilovolts. Ten feet applies to general work near lines up to 50 kilovolts. The activity decides which applies.
Power lines kill crane operators and riggers regularly, which is why Subpart CC treats them at length.
The two figures
| Situation | Minimum clearance |
|---|---|
| General work near lines up to 50 kilovolts | 10 feet |
| Crane assembly and disassembly, lines up to 350 kilovolts | 20 feet |
Above those voltages the required distance increases. The exam works with the base figures.
A scenario describing a crane working near a distribution line and one describing an electrician on a scaffold produce different answers from the same standards. Read what is being done before reaching for a figure.
Assume energized
Lines are treated as energized unless the utility owner has de-energized and visibly grounded them at the worksite.
Not switched off somewhere. De-energized and visibly grounded, confirmed at the site.
Encroachment prevention
Where work must occur closer, the employer implements measures: a dedicated spotter, range control devices, proximity alarms, or an insulating link.
A spotter is the most common and their only job is watching the clearance. They do not rig, signal or do anything else.
Operator certification
Crane operators must be certified and separately evaluated by their employer, under 29 CFR 1926.1427. Certification alone is not enough - the employer must also evaluate. Assume they are live. Read the activity.
Inspection
A comprehensive inspection at least every 12 months, alongside shift and monthly inspections.
Common questions
What clearance is required from power lines?
10 feet for general work near lines up to 50 kilovolts, and 20 feet as the default during crane assembly near lines up to 350 kilovolts.
Are lines assumed energized?
Yes, unless the utility owner has de-energized and visibly grounded them at the worksite.
What if work must occur closer?
Encroachment prevention measures such as a dedicated spotter, range control devices, proximity alarms or insulating links.
Is crane operator certification enough?
No. The employer must also evaluate the operator separately, under 29 CFR 1926.1427.
How often is a comprehensive crane inspection required?
At least every 12 months.