Perhaps:
OSHA Standard 29 CFR 1910.269 covers the operation of and maintenance work on electric power generation, transmission, and distribution lines and equipment, including such work performed in aerial lifts. See, for example, paragraphs: (g)
Personal protective equipment; (k)
Material handling and storage; (l)
Working on or near exposed energized parts; and (p)
Mechanical equipment. The electrical safety work practices contained in Section 1910.269 apply only to qualified employees (and, to a limited extent, line-clearance tree trimmers).
1 We assume that your question concerns work covered by 1910.269.
Paragraph 1910.269(l)(1)(i) requires that at least two employees be present during:
(A) Installation, removal, or repair of lines energized at more than 600 volts;
(B) Installation, removal, or repair of deenergized lines if an employee is exposed to contact with other parts energized at more than 600 volts;
(C) Installation, removal, or repair of equipment, such as transformers, capacitors, and regulators, if an employee is exposed to contact with parts energized at more than 600 volts;
(D) Work using mechanical equipment, other than insulated aerial lifts, near parts energized at more than 600 volts; and
(E) Other work exposing an employee to electrical hazards greater than or equal to those posed by operations that are specifically listed above.
However, paragraph 1910.269(l)(1)(ii) provides three exemptions to the above:
(A) Routine circuit switching, if the employer can demonstrate that conditions at the site allow the work to be performed safely;
(B) Work performed with live-line tools if the employee is neither within reach of nor otherwise exposed to contact with energized parts; and
(C) Emergency repairs to the extent necessary to safeguard the general public.
If the work does not fall under the activities listed in paragraph 1910.269(l)(1)(i) or if the work falls under that paragraph but is one of the exempted activities listed in paragraph 1910.269(l)(1)(ii), then there is no OSHA requirement to have two employees present. For work practices that require at least two employees, the standard does not specify where the second employee must be located during the performance of the work. OSHA intends, however, for the second employee to be immediately available in the event of an accident and to point out poor work practices on the part of his/her fellow employee.
Additionally, if two or more employees are present at a field location, then 29 CFR 1910.269(b)(1)(i) requires that at least two persons trained in cardiopulmonary resuscitation (CPR) be available. The exception to this is that if all new employees are trained in first aid, including CPR, within three months of their hiring dates then only one trained person need be available.