Electrical Wire Amperage Rating

Table of common electrical wire sizes and amps or fuse ratings residential sec cable other wire ampacities for 1 3 current carrying conductors in cable earth or raceway for 120 240 volt systems sized between 100 and 400 amperes.

Electrical wire amperage rating. 60 c 140 f 75 c 167 f awg mm copper. You must use the correct size wire for the current load requirement of the circuit to prevent the wire from overheating. Usually a general purpose house circuit is designed for 20. Ampacity rating copper wire conductors.

When a cord has three current carrying conductors there is a decrease in amperage. The higher the amperage rating of the circuit the larger the wires need to be in order to avoid excess heat that can melt wires and cause fires. The tables below are intended to be a general guide for wire size and amp ratings. The amperage rating of a cord is a function of the wire gauge number of current carrying conductors and length of the cord.

The proper circuit size as indicated by amperage is determined by several factors including the planned load on the circuit the number of outlets or light fixtures and the length of the circuit. The number and type of electrical devices connected to a circuit determine the ampacity requirement of the conductor. Nfpa 70 national electrical code table 310 15 b 16 size 60 c 140 f 75 c 167 f 90 c 194 f 60 c 140 f 75 c 167 f 90 c 194 f size. Awg or kcmil types tw uf types rhw thw thwn.

Likewise when the length of the cord exceeds fifty feet there is a decrease in amperage.