Original Rule
Rule 58.3-B4b
58.3-B4b) Line conductors less than 10 inches below
cases: Where a transformer case is unusually long, a crossarm supporting
line conductors of 0-750 volts may be used as a heel arm or such conductors
on an arm may be less than 10 inches below the transformer case or the hangers)
provided all of the following conditions are met:
No more than a single transformer with lower voltage of 0-750
volts is supported on the pole at the same level;
The vertical clearances between conductors on the hanger arm and such line
arm below shall not be less than as specified in Table 2, Cases 9 to 13;
It is not practicable to obtain the clearance of at least 10 inches specified
in Rule 58.3-B3;
Such 0-750 volt conductors clear the transformer case by not less than 15
inches horizontally;
Service drops are not run from the crossarm supporting 0-750 volts conductors
at that location; and
The vertical clearance of 0-750 volt conductors below the lowest point of
the transformer primary leads is not less than
18 inches for primary leads of 750-7500 volts,
24 inches for primary leads of 7500-20,000 volts,
36 inches for primary leads of 20,000-35,000 volts.
Strikeout and Underline Rule
Rule 58.3-B4b
58.3-B4b) Line conductors less than 10 inches
below cases: Where a transformer case is unusually long, a crossarm supporting
line conductors of 0-750 volts may be used as a heel arm or such conductors
on an arm may be less than 10 inches below the transformer case or the hangers)
provided all of the following conditions are met:
No more than a single transformer with lower voltage
of 0-750 volts is supported on the pole at the same level;
The vertical clearances between conductors on the hanger arm and such line
arm below shall not be less than as specified in Table 2, Cases 9 to 13;
It is not practicable to obtain the clearance of at least 10 inches specified
in Rule 58.3-B3;
Such 0-750 volt conductors clear the transformer case by not less than 15
inches horizontally;
Service drops are not run from the crossarm supporting 0-750 volts conductors
at that location; and
The vertical clearance of 0-750 volt conductors below the lowest point of
the transformer primary leads is not less than
18 inches for primary leads of 750-7500 volts,
24 inches for primary leads of 7500-20,00021,000
volts,
36 inches for primary leads of 20,000 21,000-35,000
volts.
Final Rule
Rule 58.3-B4b
58.3-B4b) Line conductors less than 10
inches below cases: Where a transformer case is unusually long, a crossarm
supporting line conductors of 0-750 volts may be used as a heel arm or such
conductors on an arm may be less than 10 inches below the transformer case
or the hangers) provided all of the following conditions are met:
No more than a single transformer with lower voltage
of 0-750 volts is supported on the pole at the same level;
The vertical clearances between conductors on the hanger arm and such line
arm below shall not be less than as specified in Table 2, Cases 9 to 13;
It is not practicable to obtain the clearance of at least 10 inches specified
in Rule 58.3-B3;
Such 0-750 volt conductors clear the transformer case by not less than 15
inches horizontally;
Service drops are not run from the crossarm supporting 0-750 volts conductors
at that location; and
The vertical clearance of 0-750 volt conductors below the lowest point of
the transformer primary leads is not less than
18 inches for primary leads of 750-7500 volts,
24 inches for primary leads of 7500-21,000 volts,
36 inches for primary leads of 21,000-35,000 volts.