Rule 20.9

20.9    Crossarm or Arm means a horizontal support attached to poles or structures generally at right angles to the conductor supported.

A.    Combination Arm means a crossarm supporting supply conductors of 0 - 750 volts and supply conductors of 750 - 7,500 volts.

B.    Related Buck Arm means a crossarm used to change the direction of all or a part of the conductors on the line arm immediately above or below. A buck arm is generally placed at right angles to the line arm.

C.    Clearance Arm means a crossarm supporting conductors installed on a pole of another line for the purpose of maintaining the prescribed clearances of this order which, if the other line did not exist, could be maintained without such clearance arm.

D.    Guard Arm means a crossarm installed on a pole not more than 4 inches directly above and approximately parallel to the messenger, cable or conductors being guarded. Guard arms shall not be used to support conductors or other line facilities except as specifically provided in these rules (see Rules 84.8-B2c and 87.7-B).

Strikeout and Underline Version

Rule 20.9

20.9    Crossarm or Arm means a horizontal support attached to poles or structures generally at right angles to the conductor supported.

A.    Combination Arm means a crossarm supporting supply conductors of 0 - 750 volts and supply conductors of 750 - 7,500 volts.

B.    Related Buck Arm means a crossarm used to change the direction of all or a part of the conductors on the line arm immediately above or below. A buck arm is generally placed at right angles to the line arm.

C.    Clearance Arm means a crossarm supporting conductors installed on a pole of another line for the purpose of maintaining the prescribed clearances of this order which, if the other line did not exist, could be maintained without such clearance arm.

D.    Guard Arm means a crossarm installed on a pole not more than 4 inches directly above and approximately parallel to the messenger, cable or conductors being guarded. Guard arms shall not be used to support conductors or other line facilities except as specifically provided in these rules (see Rules 84.8-B2c and 87.7-B).

20.8    Conductor means a material suitable for: (1) carrying electric current, usually in the form of a wire, cable or bus bar, or (2) transmitting light in the case of fiber optics.

A.    Bundle Conductor means a group of conductors of the same phase and polarity.

B.    Lateral Conductor means a conductor extending in a general horizontal direction and usually at an angle of approximately 90 degrees to the direction of the line conductors.

C.    Line Conductor means an overhead conductor which extends from the last point of support on one overhead line structure to the first point of support on another overhead line structure.

D.    Open Wire Conductors mean communication conductors separately supported.

E.    Unprotected Conductors mean supply conductors, including but not limited to lead wires, not enclosed in a grounded metal pole or not covered by: a “suitable protective covering” (see Rule22.222.8 ), grounded metal conduit, or grounded metal sheath or shield. Provisions for the use of such types of coverings are specified in certain of these rules.

F.    Vertical Conductor means a conductor extending in a general vertical direction between conductor levels on an overhead line structure.

G.    Insulated Conductors or Cables, suitable, mean supply conductors which are surrounded by an insulating material (see Rule 21.4 21.6), the dielectric strength of which is sufficient to withstand the maximum difference of potential at normal operating voltages of the circuit without breakdown or puncture. A weather-resistant covering of a supply conductor does not meet the requirements of this rule as to suitable insulation.

H.    Trolley Contact Conductor is the contact conductor itself and any energized support wire or messenger when used in catenary construction.  (See Rule 20.5-E 20.6-E.)

Final Version

Rule 20.9

20.9    Conductor means a material suitable for: (1) carrying electric current, usually in the form of a wire, cable or bus bar, or (2) transmitting light in the case of fiber optics.

A.    Bundle Conductor means a group of conductors of the same phase and polarity.

B.    Lateral Conductor means a conductor extending in a general horizontal direction and usually at an angle of approximately 90 degrees to the direction of the line conductors.

C.    Line Conductor means an overhead conductor which extends from the last point of support on one overhead line structure to the first point of support on another overhead line structure.

D.    Open Wire Conductors mean communication conductors separately supported.

E.    Unprotected Conductors mean supply conductors, including but not limited to lead wires, not enclosed in a grounded metal pole or not covered by: a “suitable protective covering” (see Rule 22.8 ), grounded metal conduit, or grounded metal sheath or shield. Provisions for the use of such types of coverings are specified in certain of these rules.

F.    Vertical Conductor means a conductor extending in a general vertical direction between conductor levels on an overhead line structure.

G.    Insulated Conductors or Cables, suitable, mean supply conductors which are surrounded by an insulating material (see Rule 21.6), the dielectric strength of which is sufficient to withstand the maximum difference of potential at normal operating voltages of the circuit without breakdown or puncture. A weather-resistant covering of a supply conductor does not meet the requirements of this rule as to suitable insulation.

H.    Trolley Contact Conductor is the contact conductor itself and any energized support wire or messenger when used in catenary construction.  (See Rule 20.6-E.)