// CODE SNIPPET
Section E3603 Service, Feeder and Grounding Electrode Conductor Sizing
JUMP TO FULL CODE CHAPTER
For a service rated at 100 through 400 amperes, the service conductors supplying the entire load associated with a one-family dwelling, or the service conductors supplying the entire load associated with an individual dwelling unit in a two-family dwelling, shall have an ampacity of not less than 83 percent of the service rating. The service rating is based on the standard ampere ratings in Section E3705.6.
For a feeder rated at 100 through 400 amperes, the feeder conductors supplying the entire load associated with a one-family dwelling, or the feeder conductors supplying the entire load associated with an individual dwelling unit in a two-family dwelling, shall have an ampacity of not less than 83 percent of the feeder rating. The feeder rating is based on the standard ampere ratings in Section E3705.6.
A feeder for an individual dwelling unit shall not be required to have an ampacity greater than that specified in Sections E3603.1.1 and E3603.1.2.
The grounded conductor ampacity shall be not less than the maximum unbalance of the load and the size of the grounded conductor shall be not smaller than the required minimum grounding electrode conductor size specified in Table E3603.4. [310.15(B)(7)]
Where correction or adjustment factors are required by Section E3705.2 or E3705.3, they shall be permitted to be applied to the ampacity associated with the temperature rating of the conductor.
Ungrounded conductors for other than dwelling units shall have an ampacity of not less than 60 amperes and shall be sized as required for feeders in Chapter 37. [230.79(D)]
Each ungrounded service conductor shall have overload protection. (230.90)
Overload protection shall be provided by an overcurrent device installed in series with each ungrounded service conductor. The overcurrent device shall have a rating or setting not higher than the allowable service or feeder rating specified in Section E3603.1. A set of fuses shall be considered to be all of the fuses required to protect all of the ungrounded conductors of a circuit. Single pole circuit breakers, grouped in accordance with Section E3601.7, shall be considered as one protective device. [230.90(A)]
Exception: Two to six circuit breakers or sets of fuses shall be permitted as the overcurrent device to provide the overload protection. The sum of the ratings of the circuit breakers or fuses shall be permitted to exceed the ampacity of the service conductors, provided that the calculated load does not exceed the ampacity of the service conductors. [230.90(A) Exception No. 3]
Overcurrent devices shall not be connected in series with a grounded service conductor except where a circuit breaker is used that simultaneously opens all conductors of the circuit. [230.90(B)]
The service overcurrent device shall be an integral part of the service disconnecting means or shall be located immediately adjacent thereto. Where fuses are used as the service overcurrent device, the disconnecting means shall be located on the supply side of the fuses. (230.91)
The grounding electrode conductors shall be sized based on the size of the service entrance conductors as required in Table E3603.4. (250.66)
GROUNDING ELECTRODE CONDUCTOR SIZEa, b, c, d, e, f
| SIZE OF LARGEST UNGROUNDED SERVICE-ENTRANCE CONDUCTOR OR EQUIVALENT AREA FOR PARALLEL CONDUCTORS (AWG/kcmil) | SIZE OF GROUNDING ELECTRODE CONDUCTOR (AWG/kcmil) | ||
| Copper | Aluminum or copper-clad aluminum | Copper | Aluminum or copper-clad aluminum |
| 2 or smaller | 1/0 or smaller | 8 | 6 |
| 1 or 1/0 | 2/0 or 3/0 | 6 | 4 |
| 2/0 or 3/0 | 4/0 or 250 | 4 | 2 |
| Over 3/0 through 350 | Over 250 through 500 | 2 | 1/0 |
| Over 350 through 600 | Over 500 through 900 | 1/0 | 3/0 |
- If multiple sets of service-entrance conductors connect directly to a service drop, set of overhead service conductors, set of underground service 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 corresponding conductors of each set. (Table 250.66)
- Where there are no service-entrance conductors, the grounding electrode conductor size shall be determined by the equivalent size of the largest service-entrance conductor required for the load to be served. (Table 250.66)
- Where protected by a ferrous metal raceway, grounding electrode conductors shall be electrically bonded to the ferrous metal raceway at both ends. [250.64(E)(1)]
- An 8 AWG grounding electrode conductor shall be protected with rigid metal conduit, intermediate metal conduit, rigid polyvinyl chloride (Type PVC) nonmetallic conduit, rigid thermosetting resin (Type RTRC) nonmetallic conduit, electrical metallic tubing or cable armor. [250.64(B)]
- Where not protected, 6 AWG grounding electrode conductor shall closely follow a structural surface for physical protection. The supports shall be spaced not more than 24 inches on center and shall be within 12 inches of any enclosure or termination. [250.64(B)]
- Where the grounding electrode conductor or bonding jumper connected to a single or multiple rod, pipe, or plate electrode(s) or any combination 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 electrode conductor shall not be required to be larger than 6 AWG copper or 4 AWG aluminum. Where the grounding electrode conductor or bonding jumper connected to a single or multiple concrete-encased electrode(s), as described in Section E3608.1.2, does not extend on to other types of electrodes that require a larger size of conductor, the grounding electrode conductor shall not be required to be larger than 4 AWG copper conductor. [250.66(A) and (B)]
Except where the equipment is marked otherwise, conductor ampacities used in determining equipment termination provisions shall be based on Table E3705.1. [110.14(C)(1)]
Related Code Sections
Section E3603 Services, Service, Feeder and Grounding Electrode Conductor Sizing
be sized based on the size of the service entrance conductors as required in Table E3603.4. (250.66) TABLE E3603.4 GROUNDING ELECTRODE CONDUCTOR ...
Residential Code 2018 of Kansas > 36 Services > E3603 Service, Feeder and Grounding Electrode Conductor Sizing
E3603.3.2 Services, Not in Grounded Conductor
Overcurrent devices shall not be connected in series with a grounded service conductor except where a circuit breaker is used that simultaneously ...
Residential Code 2018 of Kansas > 36 Services > E3603 Service, Feeder and Grounding Electrode Conductor Sizing > E3603.3 Overload Protection > E3603.3.2 Not in Grounded Conductor
E3603.3.1 Services, Ungrounded Conductor
Overload protection shall be provided by an overcurrent device installed in series with each ungrounded service conductor. The overcurrent device ...
Residential Code 2018 of Kansas > 36 Services > E3603 Service, Feeder and Grounding Electrode Conductor Sizing > E3603.3 Overload Protection > E3603.3.1 Ungrounded Conductor
E3603.3.3 Services, Location
The service overcurrent device shall be an integral part of the service disconnecting means or shall be located immediately adjacent thereto. Where ...
Residential Code 2018 of Kansas > 36 Services > E3603 Service, Feeder and Grounding Electrode Conductor Sizing > E3603.3 Overload Protection > E3603.3.3 Location
E3603.1.2 Services, Ungrounded Feeder Conductors
For a feeder rated at 100 through 400 amperes, the feeder conductors supplying the entire load associated with a one-family dwelling, or the feeder ...
Residential Code 2018 of Kansas > 36 Services > E3603 Service, Feeder and Grounding Electrode Conductor Sizing > E3603.1 Grounded and Ungrounded Service Conductor Size > E3603.1.2 Ungrounded Feeder Conductors