The 20 ft assessment, 29 CFR 1926.1408(a)(2)
Before work begins, the employer determines whether any part of the equipment, load line or load, including rigging and lifting accessories, could get closer than 20 ft to a power line. Consider the crane out to its maximum working radius in the work zone.
The traps: 10 ft is the old general rule. Measuring from the current position is the other listed error.
The three options
If the assessment says the crane could come within 20 ft, the employer uses one of:
- Option (1): deenergize and ground the line.
- Option (2): keep 20 ft of clearance.
- Option (3): keep the Table A clearance for the line's voltage.
A flat 10 ft for any voltage is not an option. Ten feet is the Table A figure only for lines up to 50 kV.
Table A clearances
- Up to 50 kV: 10 ft
- Over 50 to 200 kV: 15 ft
- Over 200 to 350 kV: 20 ft
- Over 350 to 500 kV: 25 ft
- Over 500 to 750 kV: 35 ft
- Over 750 to 1,000 kV: 45 ft
- Over 1,000 kV: set by the utility owner/operator or a registered professional engineer who is a qualified person for power transmission and distribution
The value after "to" is included in that band. A line rated exactly 200 kV is in the over 50 to 200 kV band, so 15 ft; putting a boundary voltage in the higher band is the listed error. A 230 kV line is over 200 to 350 kV, so 20 ft.
Above 1,000 kV there is no number; the crane operator does not set it, and 45 ft stops at 1,000 kV.
Getting the voltage, 1926.1408(c)
The employer gets the voltage of lines near the work zone from the utility owner/operator, who provides it within 2 working days. The 24-hour figure belongs to OSHA reporting of hospitalizations, amputations and eye losses. Five working days and 10 calendar days are not in the section.