Page 728 - 2018_IRC

SERVICES

the overload protection. The sum of the ratings of the E3603.5 Temperature limitations. Except where the equip-
circuit breakers or fuses shall be permitted to exceed ment is marked otherwise, conductor ampacities used in
the ampacity of the service conductors, provided that determining equipment termination provisions shall be based
the calculated load does not exceed the ampacity of the on Table E3705.1. [110.14(C)(1)]
service conductors. [230.90(A) Exception No. 3]
E3603.3.2 Not in grounded conductor. Overcurrent
devices shall not be connected in series with a grounded SECTION E3604
service conductor except where a circuit breaker is used OVERHEAD SERVICE AND SERVICE-
that simultaneously opens all conductors of the circuit. ENTRANCE CONDUCTOR INSTALLATION
[230.90(B)] E3604.1 Clearances on buildings. Open conductors and
E3603.3.3 Location. The service overcurrent device shall multiconductor cables without an overall outer jacket shall
be an integral part of the service disconnecting means or have a clearance of not less than 3 feet (914 mm) from the
shall be located immediately adjacent thereto. Where fuses sides of doors, porches, decks, stairs, ladders, fire escapes and
are used as the service overcurrent device, the disconnect- balconies, and from the sides and bottom of windows that
ing means shall be located on the supply side of the fuses. open. See Figure E3604.1. [230.9(A)]
(230.91) E3604.2 Vertical clearances. Overhead service conductors
E3603.4 Grounding electrode conductor size. The grounding shall not have ready access and shall comply with Sections
electrode conductors shall be sized based on the size of the ser- E3604.2.1 and E3604.2.2. (230.24)
vice entrance conductors as required in Table E3603.4. (250.66) E3604.2.1 Above roofs. Conductors shall have a vertical
TABLE E3603.4 clearance of not less than 8 feet (2438 mm) above the roof
GROUNDING ELECTRODE CONDUCTOR SIZE a, b, c, d, e, f surface. The vertical clearance above the roof level shall
SIZE OF LARGEST UNGROUNDED be maintained for a distance of not less than 3 feet (914
SERVICE-ENTRANCE CONDUCTOR SIZE OF GROUNDING mm) in all directions from the edge of the roof. See Figure
OR EQUIVALENT AREA FOR PARALLEL ELECTRODE CONDUCTOR E3604.2.1. [230.24(A)]
(AWG/kcmil)
CONDUCTORS (AWG/kcmil)
Aluminum or Aluminum or Exceptions:
Copper copper-clad Copper copper-clad 1. Conductors above a roof surface subject to pedes-
aluminum aluminum
2 or smaller 1/0 or smaller 8 6 trian traffic shall have a vertical clearance from
the roof surface in accordance with Section
1 or 1/0 2/0 or 3/0 6 4 E3604.2.2. [230.24(A) Exception No. 1]
2/0 or 3/0 4/0 or 250 4 2 2. Where the roof has a slope of 4 inches (102 mm)
Over 3/0 Over 250 2 1 / 0 in 12 inches (305 mm), or greater, the minimum
through 350 through 500 clearance shall be 3 feet (914 mm). [230.24(A)
Over 350 Over 500 1/0 3/0 Exception No. 2]
through 600 through 900
3. The minimum clearance above only the over-
a. If multiple sets of service-entrance conductors connect directly to a service hanging portion of the roof shall not be less than
drop, set of overhead service conductors, set of underground service 18 inches (457 mm) where not more than 6 feet
conductors, or service lateral, the equivalent size of the largest service-
entrance conductor shall be determined by the largest sum of the areas of the (1829 mm) of overhead service conductor length
corresponding conductors of each set. (Table 250.66) passes over 4 feet (1219 mm) or less of roof sur-
b. Where there are no service-entrance conductors, the grounding electrode face measured horizontally and such conductors
conductor size shall be determined by the equivalent size of the largest are terminated at a through-the-roof raceway or
service-entrance conductor required for the load to be served. (Table
250.66) approved support. [230.24(A) Exception No. 3]
c. Where protected by a ferrous metal raceway, grounding electrode 4. The requirement for maintaining the vertical
conductors shall be electrically bonded to the ferrous metal raceway at
both ends. [250.64(E)(1)] clearance for a distance of 3 feet (914 mm) from
d. An 8 AWG grounding electrode conductor shall be protected with rigid the edge of the roof shall not apply to the final
metal conduit, intermediate metal conduit, rigid polyvinyl chloride (Type conductor span where the service drop is attached
PVC) nonmetallic conduit, rigid thermosetting resin (Type RTRC) to the side of a building. [230.24(A) Exception
nonmetallic conduit, electrical metallic tubing or cable armor. [250.64(B)]
e. Where not protected, 6 AWG grounding electrode conductor shall closely No. 4]
follow a structural surface for physical protection. The supports shall be 5. Where the voltage between conductors does not
spaced not more than 24 inches on center and shall be within 12 inches of
any enclosure or termination. [250.64(B)] exceed 300 and the roof area is guarded or iso-
f. Where the grounding electrode conductor or bonding jumper connected to lated, a reduction in clearance to 3 feet (914 mm)
a single or multiple rod, pipe, or plate electrode(s) or any combination shall be permitted. [230.24(A) Exception No. 5]
thereof, as described in Section E3608.3, does not extend on to other types
of electrodes that require a larger size of conductor, the grounding E3604.2.2 Vertical clearance from grade. Overhead ser-
electrode conductor shall not be required to be larger than 6 AWG copper vice conductors shall have the following minimum clear-
or 4 AWG aluminum. Where the grounding electrode conductor or ances from final grade:
bonding jumper connected to a single or multiple concrete-encased
electrode(s), as described in Section E3608.1.2, does not extend on to 1. For conductors supported on and cabled together
other types of electrodes that require a larger size of conductor, the with a grounded bare messenger wire, the minimum
grounding electrode conductor shall not be required to be larger than 4
AWG copper conductor. [250.66(A) and (B)] vertical clearance shall be 10 feet (3048 mm) at the

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