Page 738 - 2018_IRC

CHAPTER 37

BRANCH CIRCUIT AND FEEDER REQUIREMENTS

ICC user note:
About this chapter: Chapter 37 addresses the sizing of conductors for feeders and branch circuits, specifies the required branch circuits,
provides for overcurrent protection of such conductors, specifies limitations for branch circuit loading, and addresses panel board ratings and
protection. Design and installation processes move directly from the service to feeders and branch circuits.

SECTION E3701 overcurrent device, multiwire branch circuits shall supply only
GENERAL line-to-neutral loads or only one appliance. [210.4(A) and
E3701.1 Scope. This chapter covers branch circuits and feed- 210.4(C)]
ers and specifies the minimum required branch circuits, the E3701.5.1 Disconnecting means. Each multiwire branch
allowable loads and the required overcurrent protection for circuit shall be provided with a means that will simultane-
branch circuits and feeders that serve less than 100 percent of ously disconnect all ungrounded conductors at the point
the total dwelling unit load. Feeder circuits that serve 100 where the branch circuit originates. [210.4(B)]
percent of the dwelling unit load shall be sized in accordance E3701.5.2 Grouping. The ungrounded and grounded cir-
with the procedures in Chapter 36. [310.15(B)(7)(2)]
cuit conductors of each multiwire branch circuit shall be
E3701.2 Branch-circuit and feeder ampacity. Branch-cir- grouped by wire markers, cable ties or similar means in at
cuit and feeder conductors shall have ampacities not less than least one location within the panelboard or other point of
the maximum load to be served. Where a branch circuit or a origination. [200.4(B)]
feeder supplies continuous loads or any combination of con- Exception: Grouping shall not be required where the
tinuous and noncontinuous loads, the minimum branch-cir- circuit conductors enter from a cable or raceway unique
cuit or feeder conductor size, before the application of any to the circuit, thereby making the grouping obvious, or
adjustment or correction factors, shall have an allowable where the conductors pass through a box or conduit
ampacity equal to or greater than the noncontinuous load plus body without a loop as described in Section
125 percent of the continuous load. [210.19(A)(1)(a) and E3905.12.2.1 or without a splice or termination.
215.2(A)(1)(a)]
[200.4(B) Exception 1 and 2].
Exception: The grounded conductors of feeders that are
not connected to an overcurrent device shall be permitted
to be sized at 100 percent of the continuous and noncon- SECTION E3702
tinuous load. [215.1(A)(1) Exception No. 2] BRANCH CIRCUIT RATINGS
E3701.3 Selection of ampacity. Where more than one calcu- E3702.1 Branch-circuit voltage limitations. The voltage
lated or tabulated ampacity could apply for a given circuit ratings of branch circuits that supply luminaires or recepta-
length, the lowest value shall be used. [310.15(A)(2)] cles for cord-and-plug-connected loads of up to 1,400 volt-
1
amperes or of less than / horsepower (0.186 kW) shall be
Exception: Where different ampacities apply to portions 4
of a circuit, the higher ampacity shall be permitted to be limited to a maximum rating of 120 volts, nominal, between
used where the total portion(s) of the circuit with the lower conductors.
ampacity does not exceed the lesser of 10 feet (3048 mm) Branch circuits that supply cord-and-plug-connected or
or 10 percent of the total circuit. [310.15(A)(2) Exception] permanently connected utilization equipment and appliances
1
rated at over 1,440 volt-amperes or / horsepower (0.186
E3701.4 Branch circuits with more than one receptacle. 4
Conductors of branch circuits supplying more than one recep- kW) and greater shall be rated at 120 volts or 240 volts, nom-
tacle for cord-and-plug-connected portable loads shall have inal. [210.6(A), (B), and (C)]
ampacities of not less than the rating of the branch circuit. E3702.2 Branch-circuit ampere rating. Branch circuits shall
[210.19(A)(2)] be rated in accordance with the maximum allowable ampere
rating or setting of the overcurrent protection device. The rat-
E3701.5 Multiwire branch circuits. All conductors for multi-
wire branch circuits shall originate from the same panelboard or ing for other than individual branch circuits shall be 15, 20, 30,
similar distribution equipment. Except where all ungrounded 40 and 50 amperes. Where conductors of higher ampacity are
conductors are opened simultaneously by the branch-circuit

2018 INTERNATIONAL RESIDENTIAL CODE ® 713
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