Wire size 100 amps 150 feet code#

Use the calculator above to size wire for basic applications, or view some of the wire ampacity charts for wire ampacity values. Good judgement should be used when sizing conductorsīecause large conductors can become costly and difficult to install, while small conductors can cause potential danger. By increasing the cross-section of the conductor (or increasing the size of the wire), the resistance decreases, and the allowable ampacity increases. However, the cross-sectional area of a conductor can also be changed to alter theĬonductor's resistance. The length of a conductor is directly proportional to its resistance. The heating of a conductor can be directly attributed from its Wire ampacity is calculated in such a way as to not exceed a certain temperature rise at a particular electrical load. However, many different external factors such as ambient temperature and conductor insulation play a part in determining

In order to properly size a wire for your application, the ampacity ratings for a wire must be understood. The ampacity rating of a wire determines the amperage that a wire can safely Amperage is the measure of electricalĬurrent flowing through a circuit. Wire for many different applications can become complex and overwhelming. Wire to prevent overheating, fire and other dangerous conditions.

Wire size 100 amps 150 feet code#

The National Electrical Code provides requirements for sizing electrical Source: NFPA 70, National Electrical Code, Table 310.15(B)(16-17) Conductor Sizing Always use the total length of the circuit for calculations.Ĭonsult with an engineer if your application requires more complex calculations. Note: It's recommended to check the ampacity of a wire after doing a voltage drop calculation. It is recommended not to exceed a voltageĭistance - Enter the one-way length of the wires in the circuit in feet. Voltage Drop - Choose the maximum percentage of the source voltage drop. In a cable, burried in the Earth, or in open air. This is typically in a raceway (cable-tray or conduit), Installation - Choose the installation method for the circuit. Common conductors are copper and aluminum. Insulation - Select the thermal rating of the insulation on the wire.Ĭonductor - Choose the material used as a conductor in the wire. To calculate ground wire size, use the Ground Wire Size Calculator.

For three-phase circuits, four wires are required. Single-phase circuits, three wires are required. This is typically single-phase or three-phase. Phases - Select the number of phases in the circuit. To multiply the nameplate FLA by 1.25 for wire sizing. While three-phase voltages are typically 208V, 230V or 480V.Īmperes - Enter the maximum current in amps that will flow through the circuit. Single-phase voltages are usually 115V or 120V, Outdoor circuits, however, are often quite long and the voltage drop can be significant.Voltage - Enter the voltage at the source of the circuit. Voltage drop occurs in any wire run, but it is rarely a problem with indoor wiring, where the distance from the circuit breaker panel to the end of the circuit is usually relatively short. However, if the cable run is long, as underground runs often are, you may need to increase the wire size to account for voltage drop-a loss of voltage in the circuit caused by the natural resistance in the wires. Sizing the wires, or conductors, for an underground cable is no different than sizing for other household circuits and is typically based on the total load, or electrical demand, of the devices on the circuit. Such an installation is typical when running a circuit to an outdoor location, such as a garage, shed or other outbuilding, or to a yard light or water feature. Underground wire for a residential circuit usually is installed with underground feeder (UF) cable, which is rated for outdoor use and direct burial. The Spruce Home Improvement Review Board.