Cranes: 1926.1408 Table A
For cranes near lines up to 350 kV, 29 CFR 1926.1408 first asks whether the equipment or load could come closer than 20 ft (the trigger). One option is then to use Table A by line voltage:
- 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
A 69 kV line falls in the over 50 to 200 kV row, so 15 ft. Traps: using the 20 ft trigger as the Table A value for every voltage is a listed common error; 20 ft is only the over 200 to 350 kV row. And each range includes its upper bound: a line of exactly 50 kV takes 10 ft, because 15 ft applies only over 50 kV. Treating the boundary as exclusive is a listed common error. The table is stepped; never interpolate.
Other equipment: 1926.600(a)(6)
Backhoes, excavators and other non-crane Subpart O equipment use 29 CFR 1926.600(a)(6), not Table A:
- lines rated 50 kV or below: 10 ft
- lines over 50 kV: 10 ft plus 0.4 in for each 1 kV over 50 kV (or twice the insulator length), never less than 10 ft
At 115 kV: 115 − 50 = 65 kV; 65 × 0.4 in = 26 in = 2 ft 2 in; 10 ft + 2 ft 2 in = 12 ft 2 in. The trap is multiplying the full voltage: 115 × 0.4 in = 46 in gives the wrong 13 ft 10 in. The 0.4 in applies only to the kV above 50.
In transit
Under 1926.600(a)(6)(iii), equipment travelling with no load and boom lowered needs:
- 4 ft for lines below 50 kV
- 10 ft for lines over 50 kV up to and including 345 kV (so 230 kV takes 10 ft)
- 16 ft for lines up to and including 750 kV
When 1926.600(a)(6) does not apply
The rule does not apply where the lines are deenergized and visibly grounded, or where insulating barriers are erected to prevent contact. A spotter, operator experience or short duration is not an exception.