AMPACITY: Welding cable ampacity (also known as current-carrying capacity or current rating) refers to the maximum amount of current (in amperes) that a cable conductor can continuously and safely carry without exceeding the operating temperature rating.

The ampacity, or amperage capacity, is the maximum amount of electrical current that the welding cable can conduct safely.

Welding Cable Ampacity and Sizing Ampacity, also known as current-carrying capacity or current rating, is the maximum amount of current that a cable can safely carry without exceeding its operating temperature rating due to the heat generated from losses and ambient heat around the cable.

Ampacity, or the amount of electrical current a cable can safely carry, is a critical factor in selecting the right welding cable. The ampacity must match the maximum output of your welding machine to avoid overloading and damaging the cable.

According to IEWC, the ampacity of 4/0 welding cable for 600-volt in-line applications is 315 Amps when the copper temperature is 60 C, and the ambient temperature is 40 C. The ampacity for secondary voltage applications is as follows based on the length of the total circuit: For 400' run - 200 Amps.