» Home Electrical Wiring
» Electrical Wiring Directory
» Residential Wiring Codes
» Need Electrical Help? Ask the Electrician
» Residential Wiring Codes
» Need Electrical Help? Ask the Electrician
Electrical Code NEC-Table310-16
|
|
Summary: Table 310-16. Allowable Ampacities of Insulated Conductors Rated 0 through 2000 Volts 60° to 90°C (140° to 194°F) Not More Than Three Current-Carrying Conductors in Raceway or Cable or Earth (Directly Buried), Based on Ambient Temperature of 30°C (86°F).
© By: Dave Rongey |
Allowable Ampacities of Insulated Conductors
Although this is the most common table used to determine wire size, this is just one example.
Based on NEC Table 310-16 as shown in the NEC Table 310-16 below the temperature rating of the insulation has much to do with how much electrical current the wire is designed to withstand.
| Allowable Ampacities of Insulated Wire Conductors Based on NEC Table 310-16 |
| 60 Deg C (140 Deg F) |
75 Deg C |
90 Deg C (194 Deg F) |
60 Deg C (140 Deg F) |
75 Deg C |
90 Deg C (194 Deg F) |
|
| Wire Types |
TW, UF |
RHW, THHW, THW, THWN, XHHW | THHN, THWN-2, XHHW |
TW,UF | RHW, THHW, THW, THWN, XHHW | THHN, THWN-2, XHHW |
| Size | Copper | Aluminum |
| #14 | 20 | 20 | 25 | - | - | - |
| #12 | 25 | 25 | 30 | 20 | 20 | 25 |
| #10 | 30 | 35 | 40 | 25 | 30 | 35 |
| #8 | 40 | 50 | 55 | 30 | 40 | 45 |
| #6 | 55 | 65 | 75 | 40 | 50 | 60 |
| #4 | 70 | 85 | 95 | 55 | 65 | 75 |
| #3 | 85 | 100 | 110 | 65 | 75 | 85 |
| #2 | 95 | 115 | 130 | 75 | 90 | 100 |
| #1 | 110 | 130 | 150 | 85 | 100 | 115 |
Although this table is true and accurate, many times the wire type is not known. There are also instances where more than one type of wire is used on a circuit. This is why it is best to use this default chart to determine the capacity of the wire sizes listed below
.
Please Note: This table is for Copper Wire Only:
| Wire | |
| #14 | 15 |
| #12 | 20 |
| #10 | 30 |
| #8 | 40 |
NEC® and National Electrical Code® are registered trade marks
of the National Fire Protection Association (NFPA).

