Original Version
Rule 54.4I
54.4-I. Under or Through Bridges, Viaducts or Similar Structures
Unprotected supply conductors which pass unattached under bridges,
viaducts or other structures shall be maintained at clearances above ground
and walkways as specified in Table 1, Cases 1 to 6 incl.; at clearances from
walls and underneath parts of such structures as specified in Table 1, Case
7; and at clearances from conductors of other classifications as specified
in Table 2, Case 3.
Conductors of 0-20,000 volts, passing under or through bridges, viaducts
or similar structures, may be attached thereto in accordance with the provision
of Rule 54.4-H2. Warning signs of a substantial character with letters
not less than 3 inches in height reading “High Voltage” for voltages in excess
of 750 volts shall be placed conspicuously on each crossarm or structural
member supporting the conductors.
In lieu of these requirements for unprotected conductors, supply conductors
which cross under bridges, viaducts or other structures shall be enclosed
in grounded metal conduit or in other effectively grounded sheath or grounded
shield suitably protected from mechanical injury.
Strikeout and Underline Version
Rule 54.4I
54.4-I. Under or Through Bridges, Viaducts or Similar Structures
Unprotected supply conductors which pass unattached under bridges,
viaducts or other structures shall be maintained at clearances above ground
and walkways as specified in Table 1, Cases 1 to 6 incl.; at clearances from
walls and underneath parts of such structures as specified in Table 1, Case
7; and at clearances from conductors of other classifications as specified
in Table 2, Case 3.
Conductors of 0-20,000 21,000 volts, passing under or through bridges, viaducts
or similar structures, may be attached thereto in accordance with the provision
of Rule 54.4-H2. Warning signs of a substantial character with letters
not less than 3 inches in height reading “High Voltage” for voltages in excess
of 750 volts shall be placed conspicuously on each crossarm or structural
member supporting the conductors.
In lieu of these requirements for unprotected conductors, supply conductors
which cross under bridges, viaducts or other structures shall be enclosed
in grounded metal conduit or in other effectively grounded sheath or grounded
shield suitably protected from mechanical injury.
Final Version
Rule 54.4I
54.4-I. Under or Through Bridges, Viaducts or Similar Structures
Unprotected supply conductors which pass unattached under
bridges, viaducts or other structures shall be maintained at clearances above
ground and walkways as specified in Table 1, Cases 1 to 6 incl.; at clearances
from walls and underneath parts of such structures as specified in Table
1, Case 7; and at clearances from conductors of other classifications as
specified in Table 2, Case 3.
Conductors of 0-21,000 volts, passing under or through bridges, viaducts
or similar structures, may be attached thereto in accordance with the provision
of Rule 54.4-H2. Warning signs of a substantial character with letters
not less than 3 inches in height reading “High Voltage” for voltages in excess
of 750 volts shall be placed conspicuously on each crossarm or structural
member supporting the conductors.
In lieu of these requirements for unprotected conductors, supply conductors
which cross under bridges, viaducts or other structures shall be enclosed
in grounded metal conduit or in other effectively grounded sheath or grounded
shield suitably protected from mechanical injury.