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Decision Number 12-01-0329

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Original Version

Table 1

 

Table 1: Basic Minimum Allowable Vertical Clearance of Wires above Railroads, Thoroughfares, Ground or Water Surfaces; Also Clearances from Poles, Buildings, Structures or Other Objects ( nn ) (Letter References Denote Modifications of Minimum Clearances as Referred to in Notes Following This Table)

 

Case
No.

Nature of Clearance

Wire or Conductor Concerned

A

Span Wires (Other than TrolleySpan Wires) Overhead Guys and Messengers

B
Communication Conductors (IncludingOpen Wire, Cables and Service Drops), Supply Service Drops of 0 - 750 Volts   

C
Trolley Contact, Feeder and Span Wires, 0 - 5,000  Volts    

D

Supply Conductors of 0 - 750 Volts and Supply Cables Treated as in
Rule 57.8

E
Supply Conductors and Supply Cables, 750 - 22,500 Volts   

F
Supply Conductors and Supply Cables, 22.5 - 300 kV   

G
Supply Conductors and Supply Cables, 300 - 550 kV(
mm )

14

Radial clearance of bare line conductors from vegetation in Extreme and Very High Fire Threat Zones in Southern California (aaa) (ddd) (hhh) (jjj)

-

-

18 inches

(bbb)

-

48 inches

(bbb) (iii)

48 inches

(fff)

120 inches

(ggg)


References to Rules Modifying Minimum Clearances in Table 1

 

(fff) 

Clearances in this case shall be increased for conductors operating above 88 kV, to the following:

  1.

Conductors operating between 88kV and a 110 kV shall maintain a 60 inch clearance

  2.

Conductors operating above 110 kV shall maintain a 120 inch clearance

(ggg) 

Shall be increased by 0.40 inch per kV in excess of 500 kV

(hhh)

Extreme and Very High Fire Threat Zones are defined by California Department of Forestry and Fire Protectionís Fire and Resource Assessment Program (FRAP) Fire Threat Map. The FRAP Fire Threat Map is to be used to establish approximate boundaries for purposes of this rule. The boundaries of the map are to be broadly construed, and utilities should use their own expertise and judgment to determine if local conditions require them to adjust the boundaries of the map. Southern California shall be defined as the following: Santa Barbara, Ventura, San Bernardino, Riverside, Los Angeles, Orange, and San Diego Counties.

(iii)  

May be reduced to 18 inches for conductors operating less than 2.4 kV.

(jjj) 

Clearances in this case shall not apply to orchards of fruit, nut or citrus trees that are plowed or cultivated. In those areas Case 13 clearances shall apply.

 

 

Strikeout and Underline Version

Table 1

 

 

Table 1: Basic Minimum Allowable Vertical Clearance of Wires above Railroads, Thoroughfares, Ground or Water Surfaces; Also Clearances from Poles, Buildings, Structures or Other Objects ( nn ) (Letter References Denote Modifications of Minimum Clearances as Referred to in Notes Following This Table)

 

Case
No.

Nature of Clearance

Wire or Conductor Concerned

A

Span Wires (Other than TrolleySpan Wires) Overhead Guys and Messengers

B
Communication Conductors (IncludingOpen Wire, Cables and Service Drops), Supply Service Drops of 0 - 750 Volts   

C
Trolley Contact, Feeder and Span Wires, 0 - 5,000  Volts    

D

Supply Conductors of 0 - 750 Volts and Supply Cables Treated as in
Rule 57.8

E
Supply Conductors and Supply Cables, 750 - 22,500 Volts   

F
Supply Conductors and Supply Cables, 22.5 - 300 kV   

G
Supply Conductors and Supply Cables, 300 - 550 kV(
mm )

14

Radial clearance of bare line conductors from vegetation in Extreme and Very High Fire Threat Zones in Southern California (aaa) (ddd) (hhh) (jjj)

-

-

18 inches

(bbb)

-

48 inches

(bbb) (iii)

48 inches

(fff)

120 inches

(ggg)


References to Rules Modifying Minimum Clearances in Table 1

 

(fff) 

Clearances in this case shall be increased for conductors operating above 88 72 kV, to the following:

  1.

Conductors operating between 88 72 kV and a 110 kV shall maintain a 60 72  inch clearance

  2.

Conductors operating above 110 kV shall maintain a 120 inch clearance

(ggg) 

Shall be increased by 0.40 inch per kV in excess of 500 kV

(hhh)

Extreme and Very High Fire Threat Zones are defined by California Department of Forestry and Fire Protectionís Fire and Resource Assessment Program (FRAP) Fire Threat Map. The FRAP Fire Threat Map is to be used to establish approximate boundaries for purposes of this rule. The boundaries of the map are to be broadly construed, and utilities should use their own expertise and judgment to determine if local conditions require them to adjust the boundaries of the map. Southern California shall be defined as the following: Santa Barbara, Ventura, San Bernardino, Riverside, Imperial, Los Angeles, Orange, Riverside, Santa Barbara, San Bernardino, and San Diego and Ventura Counties.

(iii)  

May be reduced to 18 inches for conductors operating less than 2.4 kV.

(jjj) 

Clearances in this case shall not apply to orchards of fruit, nut or citrus trees that are plowed or cultivated. In those areas Case 13 clearances shall apply.

 

 

Final Version

Table 1

 

 

Table 1: Basic Minimum Allowable Vertical Clearance of Wires above Railroads, Thoroughfares, Ground or Water Surfaces; Also Clearances from Poles, Buildings, Structures or Other Objects ( nn ) (Letter References Denote Modifications of Minimum Clearances as Referred to in Notes Following This Table)

 

Case
No.

Nature of Clearance

Wire or Conductor Concerned

A

Span Wires (Other than TrolleySpan Wires) Overhead Guys and Messengers

B
Communication Conductors (IncludingOpen Wire, Cables and Service Drops), Supply Service Drops of 0 - 750 Volts   

C
Trolley Contact, Feeder and Span Wires, 0 - 5,000  Volts    

D

Supply Conductors of 0 - 750 Volts and Supply Cables Treated as in
Rule 57.8

E
Supply Conductors and Supply Cables, 750 - 22,500 Volts   

F
Supply Conductors and Supply Cables, 22.5 - 300 kV   

G
Supply Conductors and Supply Cables, 300 - 550 kV(
mm )

14

Radial clearance of bare line conductors from vegetation in Extreme and Very High Fire Threat Zones in Southern California (aaa) (ddd) (hhh) (jjj)

-

-

18 inches

(bbb)

-

48 inches

(bbb) (iii)

48 inches

(fff)

120 inches

(ggg)


References to Rules Modifying Minimum Clearances in Table 1

 

(fff) 

Clearances in this case shall be increased for conductors operating above  72 kV, to the following:

  1.

Conductors operating between  72 kV and a 110 kV shall maintain a 72  inch clearance

  2.

Conductors operating above 110 kV shall maintain a 120 inch clearance

(ggg) 

Shall be increased by 0.40 inch per kV in excess of 500 kV

(hhh)

Extreme and Very High Fire Threat Zones are defined by California Department of Forestry and Fire Protectionís Fire and Resource Assessment Program (FRAP) Fire Threat Map. The FRAP Fire Threat Map is to be used to establish approximate boundaries for purposes of this rule. The boundaries of the map are to be broadly construed, and utilities should use their own expertise and judgment to determine if local conditions require them to adjust the boundaries of the map. Southern California shall be defined as the following: Imperial, Los Angeles, Orange, Riverside, Santa Barbara, San Bernardino, San Diego and Ventura Counties.

(iii)  

May be reduced to 18 inches for conductors operating less than 2.4 kV.

(jjj) 

Clearances in this case shall not apply to orchards of fruit, nut or citrus trees that are plowed or cultivated. In those areas Case 13 clearances shall apply.