// CODE SNIPPET
E3603.1.1 Ungrounded Service Conductors
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TABLE E3603.1.1 (Table 310.12)
SINGLE-PHASE DWELLING SERVICES AND FEEDERS
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. If no adjustment or correction factors are required, Table E3603.1.1 shall be permitted to be applied.
TABLE E3603.1.1 (Table 310.12)
| SERVICE OR FEEDER RATING (amperes) | CONDUCTOR (AWG or kcmil) | |
| Copper | Aluminum or Copper-clad Aluminum | |
| 100 | 4 | 2 |
| 110 | 3 | 1 |
| 125 | 2 | 1/0 |
| 150 | 1 | 2/0 |
| 175 | 1/0 | 3/0 |
| 200 | 2/0 | 4/0 |
| 225 | 3/0 | 250 |
| 250 | 4/0 | 300 |
| 300 | 250 | 350 |
| 350 | 350 | 500 |
| 400 | 400 | 600 |
Related Code Sections
E3603.1.1 Services, Ungrounded Service Conductors
For a service rated at 100 through 400 amperes, the service conductors supplying the entire load associated with a one-family dwelling ...
Residential Code 2021 of Colorado > 36 Services > E3603 Service, Feeder and Grounding Electrode Conductor Sizing > E3603.1 Grounded and Ungrounded Service Conductor Size > E3603.1.1 Ungrounded Service Conductors