Overhead lines requirements

The employer must ascertain the pole is capable of sustaining the additional or unbalanced stresses before employees climb it. Employers must check that elevated structures can support the loads imposed by climbing or installing/removing equipment—and if they cannot, brace or otherwise support the pole or structure so it will not fail (1926.964(a)(2)).

• Use the test methods in Appendix D when evaluating wood poles as noted in paragraph (a)(2).
• If inspection or testing shows insufficient strength, provide bracing, shoring, or other supports before work proceeds (1926.964(a)(2)).

Employees must wear electrical protective equipment or use insulated devices and must not contact the pole with uninsulated parts of their bodies when handling poles near exposed energized conductors. Employers must ensure each employee uses approved insulating protection or insulating tools to prevent contact with energized conductors (1926.964(a)(3)(ii)).

• Examples include insulating gloves, sleeves, protective equipment rated for the voltage, or insulated handling tools.
• Employers should perform a hazard assessment to select appropriate PPE consistent with OSHA guidance on PPE hazard assessment (PPE hazard assessment guidance).

No; a pole may not contact an exposed energized overhead conductor while it is being set, moved, or removed. Employers must prevent any contact between the pole and energized conductors during these operations (1926.964(a)(3)(i)).

• Use insulated devices, maintain safe clearances, and coordinate movements to ensure no contact occurs.
• If contact is possible, treat the pole and nearby items as energized and use insulated equipment and procedures (1926.964(a)(3)(ii)).

Employers must physically guard the holes used for placing poles or ensure employees attend (watch over) the holes whenever anyone is working nearby. This prevents falls into excavations used for poles (1926.964(a)(3)(iii)).

• Guards can be barriers, covers, or other physical means; alternatively an employee must be assigned to monitor the hole.
• Make sure guards or attendants remain in place for the entire time work is occurring near the hole.

When installed or removed lines can contact energized parts, the employer must use the tension-stringing method, barriers, or other equivalent measures to minimize the possibility of contact with energized power lines or equipment. The goal is to reduce the chance the new or removed conductors will touch energized parts (1926.964(b)(1)).

• Examples include controlled tension-stringing setups, insulating barriers, and temporary supports that keep conductors away from energized lines.
• Plan stringing operations and communicate between reel tender and pulling-rig operator to maintain safety (1926.964(b)(9)).

Employers must provide the protective measures in 1926.959(d)(3) whenever installing or removing conductors or cables close enough to energized conductors that a failure of the pulling/tensioning equipment, the conductor/cable being pulled, or previously installed lines or equipment could energize the pulling equipment or the conductor/cable being handled (1926.964(b)(2)).

• The three failure conditions triggering this requirement are: failure of pulling/tensioning equipment, failure of the conductor or cable being pulled, or failure of previously installed lines or equipment (1926.964(b)(2)(i)-(iii)).
• See the protective measures spelled out in 1926.959(d)(3).

If conductors being installed or removed cross over energized conductors in excess of 600 volts and if the circuit-interrupting devices' design permits, or for live-line barehand work when the devices' design permits, the employer must render the automatic-reclosing feature inoperable. This prevents automatic re-energizing while work is in progress (1926.964(b)(3) and 1926.964(c)(4)).

• Coordinate with the utility or circuit owner to ensure reclosing functions are disabled where required.
• If disabling is not possible, treat lines as energized and use appropriate protective practices and equipment.

Before installing lines parallel to existing energized lines, the employer must determine the approximate induced voltage in the new lines or assume the induced voltage is hazardous and take precautions. If induction could create a hazardous voltage, temporary protective grounds must be used unless the employer can demonstrate the lines are not subject to hazardous induction (1926.964(b)(4)(i)-(ii)).

• Appendix C provides guidelines for protecting employees from hazardous differences in electric potential.
• The note explains hazard thresholds: without protection, currents as low as 1 mA through a 500-ohm resistor can create a hazard; with protection for involuntary reactions, the threshold is 6 mA (1926.964(b)(4)).

Employers must keep reel-handling and pulling/tensioning equipment in safe operating condition, leveled and aligned; ensure employees do not exceed rated loads for stringing and pulling equipment; and repair or replace defective pulling lines and accessories (1926.964(b)(5)-(7)).

• Verify load ratings for stringing lines, conductor grips, rigging, and hoists and ensure operations do not exceed those ratings (1926.964(b)(6)).
• Remove defective pulling lines from service immediately and tag or mark them until repaired or replaced (1926.964(b)(7)).

Employees may not use conductor grips on wire rope unless the manufacturer specifically designed the grip for that application. Employers must ensure grips used are appropriate for the intended use (1926.964(b)(8)).

• Always follow manufacturer instructions and specifications for conductor grips.
• Using improperly rated grips can lead to slippage, dropped loads, or conductor damage.

Employers must ensure reliable two-way communications between the reel tender and the pulling-rig operator and must keep employees out from directly under overhead operations while conductor or pulling lines are in motion, except when necessary to guide the stringing sock or board over or through the sheave. Employees may only operate the pulling rig when it is safe to do so (1926.964(b)(9)-(11)).

• Unsafe conditions include employees in prohibited locations, hang-ups, and slipping conductor grips (note to (b)(10)).
• Plan movements and maintain communication to prevent workers from being below moving conductors (1926.964(b)(11)).

Before using or supervising live-line barehand techniques on energized circuits, an employee must complete training conforming to 1926.950(b) in the technique and in the safety requirements of 1926.964(c). This ensures workers understand the unique hazards and procedures for live-line barehand work (1926.964(c)(1)).

• Training should cover procedures, emergency actions, equipment limitations, and minimum approach distances.
• OSHA guidance on PPE hazard assessments can inform employers’ selection of protective equipment for such work (PPE hazard assessment guidance).

Before live-line barehand work, the employer must determine the nominal voltage rating of the circuit, the clearances to ground of lines and other energized parts where work will be done, and the voltage limitations of equipment employees will use (1926.964(c)(2)(i)-(iii)).

• Use this information to verify equipment ratings, minimum approach distances, and safe work planning.
• Document findings and ensure workers are trained on these site-specific conditions (1926.964(c)(2)).

Insulated equipment, insulated tools, and aerial devices and platforms used for live-line barehand work must be designed, tested, and made for that technique, and employees must keep tools and equipment clean and dry while in use (1926.964(c)(3)(i)-(ii)).

• Use only devices and tools rated and certified for live-line barehand applications.
• Establish cleaning and inspection protocols to maintain insulation integrity during use.

Employers must provide a conductive bucket liner or other conductive device for bonding the insulated aerial device to the energized line or equipment, and the employee must be connected to that liner (for example, by conductive shoes or leg clips). The employee must bond the conductive device to the energized conductor with a positive connection before contacting the energized part, and the connection must remain attached until work is complete (1926.964(c)(6)-(7)).

• Bonding equalizes potentials between employee/bucket and the energized part to prevent hazardous differences in potential.
• Provide electrostatic shielding where potential differences pose a hazard (1926.964(c)(6)(ii)).

Aerial lifts used for live-line barehand work must have dual controls: upper controls within easy reach of the employee in the bucket and lower controls near the base of the boom that can override operation at any time. Lower ground-level controls may not be operated while an employee is in the lift except in an emergency (1926.964(c)(8)(i)-(ii) and (c)(9)).

• Ensure lower controls can immediately stop or override boom movement.
• Train operators and spotters on when emergency ground-level control use is permitted.

Before elevating an aerial lift into the work position, employees must check all controls (both ground and bucket) to ensure they are in proper working condition, and they must ground the body of the truck or barricade it and treat it as energized before elevating the boom (1926.964(c)(10)-(11)).

• Perform functional tests of upper and lower controls and emergency stop features.
• Grounding or barricading the truck body prevents hazardous potential differences at the worksite.

A boom-current test consists of placing the bucket in contact with an energized source equal to the voltage to be encountered for at least 3 minutes and measuring leakage current; it must be performed before starting work each day, any time a higher voltage is encountered, and when changed conditions indicate a need for another test. The leakage current must not exceed 1 microampere per kilovolt of nominal phase-to-ground voltage (1926.964(c)(12)(i)-(ii)).

• Immediately suspend work if any equipment malfunction is indicated by the test (1926.964(c)(12)(iii)).
• Keep records or logs of boom-current tests and corrective actions when tests fail.

Employers must ensure employees maintain the minimum approach distances established under 1926.960(c)(1)(i) from grounded objects and from lines and equipment at different potentials than the live-line bonding, unless insulating guards cover those grounded objects and other lines and equipment. This includes maintaining phase-to-ground clearances when positioning the bucket and while approaching, leaving, or bonding to an energized circuit (1926.964(c)(13)-(15)).

• Establish minimum approach distances based on nominal voltages per 1926.960(c)(1)(i).
• Use nonconductive measuring devices to help employees maintain required clearances (1926.964(c)(18)).

Except during emergency restoration, employers must stop live-line barehand work and tower/structure work when adverse weather conditions—such as nearby thunderstorms, high winds, snow, or ice storms—would make the work hazardous despite implementing required work practices. For live-line barehand work, winds that reduce clearances below the minimum approach distances also prohibit work unless insulating guards are used (1926.964(c)(5) and 1926.964(d)(4)).

• Identify weather conditions that can change clearances or equipment performance and suspend work proactively.
• Adverse weather exceptions are limited to emergency restoration operations only (1926.964(d)(4)).

Where differences in potentials at the worksite pose a hazard to employees, the employer must provide electrostatic shielding designed for the voltage being worked. Employees must bond the conductive bucket liner or device to the energized conductor by a positive connection before contact (1926.964(c)(6)(ii) and 1926.964(c)(7)).

• Electrostatic shielding prevents hazardous potential gradients across the bucket and worker.
• Ensure shielding is rated and tested for the specific nominal voltage of the circuit.

Employees may not use handlines between the bucket and the boom or between the bucket and the ground; nonconductive handlines from conductor to ground are allowed if not supported from the bucket. Employees must not pass uninsulated equipment or material between a pole or structure and an aerial lift while a bonded worker is attached to an energized part (1926.964(c)(16) and 1926.964(c)(17)).

• Restrict use of ropes or lines that could create conductive paths into or out of the bucket.
• Prevent passing uninsulated tools or materials that could bridge potentials and create a shock hazard.

If the boom-current test indicates any malfunction in the aerial lift equipment, the employer must immediately suspend live-line barehand work from that aerial lift (1926.964(c)(12)(iii)).

• Remove the equipment from service and have it inspected and repaired by qualified personnel before returning it to use.
• Document test failure, corrective actions, and re-test results.

Employers must ensure no employee is under a tower or structure while work is in progress unless it is necessary to assist employees working above; employees must use tag lines or similar devices to control tower sections being raised unless using them would create a greater hazard; and employees may not detach a loadline from a member or section until they have safely secured the load (1926.964(d)(1)-(3)).

• Use tag lines to control orientation of raised sections and prevent uncontrolled motion.
• Secure loads and rigging points before disconnecting loadlines to prevent dropped sections.

A nonconductive measuring device must be readily accessible to employees performing live-line barehand work to help them maintain the required minimum approach distance (1926.964(c)(18)).

• Examples include insulated measuring rods or marked nonconductive poles.
• Train workers in using the device to verify clearances before proceeding with bonding or contact.

An employer may omit temporary protective grounds only if they can demonstrate the lines being installed are not subject to induction of a hazardous voltage; otherwise, the lines must be treated as energized and temporary protective grounds placed to prevent hazardous differences in electric potential (1926.964(b)(4)(ii)).

• Use Appendix C guidelines to design grounding locations and arrangements that prevent hazardous potentials.
• When in doubt, treat the lines as energized and apply temporary grounds to protect employees.

Examples of unsafe conditions include employees in prohibited locations under moving conductors, conductor and pulling line hang-ups, and slipping of the conductor grip. If these or other unsafe conditions exist, employers must not continue pulling operations until hazards are corrected (note to 1926.964(b)(10) and 1926.964(b)(11)).

• Maintain communication and stop the operation when hang-ups or slippage occur.
• Re-secure grips, clear personnel from hazards, and only resume when the pulling rig can be operated safely (1926.964(b)(10)-(11)).

While approaching, leaving, or bonding to an energized circuit, the employee must maintain the minimum approach distances established under 1926.960(c)(1)(i) between themselves and any grounded parts (including lower boom and truck parts) and between themselves and conductive objects energized at different potentials (1926.964(c)(14)).

• Employers should set and enforce site-specific minimum approach distances based on the nominal voltages per 1926.960(c)(1)(i).
• Use nonconductive measuring devices to confirm distances before bonding.