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Subchapter 5. Electrical Safety Orders
Group 1. Low-Voltage Electrical Safety Orders
Article 60. Oil and Gas Wells
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§2548.25. Wiring Methods.

(a) Where drilling platforms are not enclosed around the drilling operation, all wiring and equipment within 25 feet of the casing of the well being drilled shall be of the type required for Class I, Division 2, or be installed in enclosed areas supplied with adequate ventilation. The electrical power supply to wiring and equipment within positive pressure ventilated areas shall be arranged to prevent energizing the electrical wiring and apparatus until air pressure has been established, for not less than 2 minutes, and arranged to automatically actuate an audible and visual alarm with a 5-minute shut-down time delay to allow safe operational shutdown prior to de-energizing the wiring and apparatus when the ventilation fails.

Enclosed areas supplied with positive pressure ventilation from a nonhazardous area shall be permitted to be classified as nonhazardous areas, provided no flammable vapor source exists within the enclosed areas.

(b) Special locomotive cables and other equivalent portable cables may be run in cable trays under the following conditions in all locations:

(1) Open cable trays may be run horizontally under floors or ceilings.

(2) In all locations, solid covers shall be installed on horizontal runs where persons or materials may accidentally contact the conductors.

(3) Vertical runs of trays shall be totally enclosed.

(4) Where the rig moves over a series of wellholes and a transverse section of cable tray drops trailing cables in a long fixed runway tray, cleats or other means shall be used to secure the cable against shifting in the moving section of the tray.

(5) For single hole setups onshore, cables may be buried in the earth or run in covered, wooden troughs between outdoor units of equipment. A substantial nominal 2-inch thick wooden cover, or equivalent, shall be installed over the trough.

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.


1. Editorial correction of NOTE filed 11-2-83 (Register 83, No. 45).

2. Amendment deleting Title 24 cross reference filed 8-27-86; effective thirtieth day thereafter (Register 86, No. 37).

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