For everyone's safety, clearance is required from our primary and secondary power lines, poles and transformers.
If your business is planning on doing work at a location that is at or near Duquesne Light Company (DLC) energized 138kV electric lines, there are certain risks attendant to the performance of your work. Your work must conform to the Occupational Safety and Health Administration standards, including those concerning work near all energized electric lines, which are codified at 29 CFR 1910.333.
A minimum working clearance must be maintained from all overhead conductors. This is based on 29 CFR 1910.333(c)(3)(i) which states:
- "(A) When an unqualified person is working in an elevated position near overhead lines, the location shall be such that the person and the longest conductive object he or she may contact cannot come closer to any unguarded, energized overhead line than the following distances:
- (1) For voltages to ground 50kV or below — 10 ft. (305 cm) and
- (2) For voltages to ground over 50kV — 10 ft. (305 cm) plus 4 in. (10cm) for every 10kv over 50kv.
- (B) When an unqualified person is working on the ground in the vicinity of overhead lines, the person may not bring and conductive object closer to any unguarded, energized overhead lines than the distances given in paragraph (c)(3)(i)(A) of this section."
This section also notes: "For voltages normally encountered with overhead power lines, objects which do not have an insulating rating for the voltage involved are considered to be conductive."
A minimum clearance also must be maintained from all overhead conductors to any part of all cranes, mechanized equipment or trucks with dump bodies. This is based on the requirements listed in 29 CFR 1926.600(a)(6) which states, "All equipment covered by this subpart shall comply with the requirements of Paragraph 1926.550(a)(15) when working or being moved in the vicinity of power lines..."
The referenced paragraph 1926.550(a)(15) states:
- "(a)(15) Except where electrical distribution and transmission lines have been deenergized and visibly grounded at point of work or where insulating barriers, not a part of or an attachment to the equipment or machinery, have been erected to prevent physical contact with the lines, equipment or machines shall be operated proximate to power lines only in accordance with the following:
- (i) For lines rated 50kV or below, minimum clearance between the lines and any part of the crane or load shall be 10 feet:
- (ii) For lines rated over 50kV, minimum clearance between any part of the crane or load shall be 10 feet plus 0.4 inch for every 1kV over 50kV, or twice the length of the line insulator, but never less than 10 feet."
Your attention is also directed to the following subparagraph 1926.550:
- "(a)(15)(iv) A person shall be designated to observe clearance of the equipment and give timely warning for all operators where it is difficult for the operator to maintain the desired clearance by visual means:
- (a)(15)(v) Cage type boom guards, insulating links, or proximity warning devices may be used on cranes, but the use of such devices shall not alter the requirements of any other regulation of this part even if such device is required by law or regulation.
- (a) General requirements. (1) The employer shall comply with the manufacturer’s specifications and limitations applicable to the operation of any and all cranes and derricks. Where manufacturer's specifications based on the determinations of a qualified engineer competent in this field and such determinations will be appropriately documented and recorded. Attachments used with cranes shall not exceed the capacity, rating, or scope recommended by the manufacturer."
In the future, if you have work in an area where you or your employees will be working near DLC lines or where your equipment may come into contact with DLC facilities, please notify your DLC Account Manager or call DLC at 412-393-7100 and a DLC representative will be sent to the job site to assist you.
DLC is providing this information to assist your company in maintaining safe working conditions for your employees. DLC, however, does not assume any responsibility or obligation with regard to your employees or to your company's compliance with OSHA standards. Compliance with all OSHA standards, including, but not limited to those identified above is solely the responsibility of your company.