§ 2940.2. Clearances.  


Latest version.
  • (a) No employee shall be permitted to approach or take any conductive object without an approved insulating handle closer to exposed energized parts than shown in Table 2940.2-1 through Table 2940.2-3 unless:
    (1) The employee is insulated or guarded from the energized part (gloves or gloves with sleeves rated for the voltage involved shall be considered insulation of the employee from the energized part), or
    (2) The energized part is insulated or guarded from the employee and any other conductive object at a different potential.
    (b) When performing work with live line tools, minimum clear distances in Table 2940.2-1 through Table 2940.2-3 shall be maintained. Conductor support tools, such as link sticks, strain carriers, and insulator cradles, shall be permitted to be used provided that the clear insulation is at least as long as the insulator string or the minimum distance specified in Table 2940.2-1 through Table 2940.2-3 for the operating voltage.
    TABLE 2940.2-1
    ALTERNATING CURRENT - MINIMUM
    APPROACH DISTANCE
    Nominal Voltage in
    Distance
    Kilovolts Phase to Phase
    Phase to Ground Exposure
    ft-in
    0.6 to 15
    2-1
    15.1 to 36.0
    2-4
    36.1-46.0
    2-7
    46.1-72.5
    3-0
    72.6-121
    3-4
    121.1-145
    3-7
    145.1-169
    4-0
    169.1-242
    5-3
    242.1-362
    8-6
    362.1-552
    11-3
    552.1-765
    15-0
    NOTE 1: These distances take into consideration the highest switching surge an employee will be exposed to on any system with air as the insulating medium and the maximum voltages shown.
    NOTE 2: The clear live-line tool distance shall equal or exceed the values for the indicated voltage ranges.
    TABLE 2940.2-2
    AC LIVE-LINE WORK MINIMUM
    APPROACH DISTANCE
    WITH OVERVOLTAGE FACTOR
    PHASE TO GROUND EXPOSURE
    Max
    anticipated
    per-unit
    Distances in feet-inches
    transient
    over
    Maximum Phase to Phase Voltage in Kilovolts
    voltage
    121
    145
    169
    242
    362
    552
    800
    1.5
    6-0
    9-8
    1.6
    6-6
    10-8
    1.7
    7-0
    11-8
    1.8
    7-7
    12-8
    1.9
    8-1
    13-9
    2.0
    2-5
    2-9
    3-0
    3-10
    5-3
    8-9
    14-11
    2.1
    2-6
    2-10
    3-2
    4-0
    5-5
    9-4
    2.2
    2-7
    2-11
    3-3
    4-1
    5-9
    9-11
    2.3
    2-8
    3-0
    3-4
    4-3
    6-1
    10-6
    2.4
    2-9
    3-1
    3-5
    4-5
    6-4
    11-3
    2.5
    2-9
    3-2
    3-6
    4-6
    6-8
    2.6
    2-10
    3-3
    3-8
    4-8
    7-1
    2.7
    2-11
    3-4
    3-9
    4-10
    7-5
    2.8
    3-0
    3.5
    3-10
    4-11
    7-9
    2.9
    3-1
    3-6
    3-11
    5-1
    8-2
    3.0
    3-2
    3-7
    4-0
    5-3
    8-6
    NOTE 1: The distance specified in this table may be applied only where the maximum anticipated per-unit transient overvoltage has been determined by engineering analysis and has been supplied by the employer. Table 2940.2-1 applies otherwise
    NOTE 2: The distances specified in this table are the air and live-line tool distances.
    TABLE 2940.2-3
    DC LIVE-LINE WORK MINIMUM APPROACH DISTANCE
    WITH OVERVOLTAGE FACTOR
    Distance in feet-inches
    Maximum anticipated
    Maximum line-to-ground
    per-unit transient
    voltage in kilovolts
    overvoltage
    250
    400
    500
    600
    750
    1.5 or lower
     
    3-8
    5-3
    6-9
    8-7
    11-10
    1.6
     
    3-10
    5-7
    7-4
    9-5
    13-1
    1.7
     
    4-1
    6-0
    7-11
    10-3
    14-4
    1.8
     
    4-3
    6-5
    8-7
    11-2
    15-9
    NOTE 1: The distances specified in this table may be applied only where the maximum anticipated per-unit transient overvoltage has been determined by engineering analysis and has been supplied by the employer. However, if the transient overvoltage factor is not known, a factor of 1.8 shall be assumed.
    NOTE 2: The distances specified in this table are the air and live-line tool distances.
    (c) Minimum approach distance (Tables 2940.2-1 through 2940.2-3) shall be adjusted to account for work locations above 3,000 feet using altitude correction factors (Table 2940.2-4).
    TABLE 2940.2-4
    ALTITUDE CORRECTION FACTOR
    Altitude (ft)
    Correction Factor
    Sea level to 3000
    1.00
    3,001 to 4,000
    1.02
    4,001-5,000
    1.05
    5,001-6,000
    1.08
    6,001-7,000
    1.11
    7,001-8,000
    1.14
    8,001-9,000
    1.17
    9,001-10,000
    1.20
    10,001-12,000
    1.25
    12,001-14,000
    1.30
    14,001-16,000
    1.35
    16,001-18,000
    1.39
    18,001-20,000
    1.44
    NOTE 1: Minimum approach distances from Table 2940.2-1 through Table 2940.2-3 shall be multiplied to the corresponding correction factor in Table 2940.2-4 to obtain the correct minimum approach distance, adjusted to account for higher altitudes.
    NOTE 2: The data used to formulate this was obtained from the test data taken with standard atmospheric condition. Standard atmospheric conditions are defined as temperatures above freezing, wind less than 15mph, unsaturated air, normal barometer (30 inches of mercury at sea level), uncontaminated air, and clean and dry insulators. If standard atmospheric conditions do not exist, extra care must be taken.
HISTORY
1. Amendment filed 12-10-87; operative 1-9-88 (Register 88, No. 1).
2. Amendment of subsection (b) and Table filed 12-12-94; operative 1-11-95 (Register 94, No. 50).
3. Editorial correction of Table (Register 95, No. 32).
4. Amendment of subsection (a)(1), table and table note filed 11-25-97; operative 12-25-97 (Register 97, No. 48).
5. Amendment filed 7-26-2000; operative 8-25-2000 (Register 2000, No. 30).
6. Amendment filed 4-28-2014; operative 7-1-2014 (Register 2014, No. 18).

Note

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.