Chop Saw Tripping a Breaker and Use of a Long Extension Cord

How Extension Cords Work

• An extension cord is simply an extension of electrical power from the receptacle to the appliance. Not all extension cords are alike, however. Cords are rated by the electrical load they are capable of carrying, with 10-gauge, 12-gauge and 14-gauge wires the most common extension cord sizes. Undersized extension cords are cords that use a lighter gauge of copper wiring, insufficient for the electrical requirement of the appliance. For example, 14-gauge extension cords are lightweight and thin, best suited for extending lamps or radios. When used with a heavy-duty power saw, the cord overheats and leaks voltage, unable to sustain the electrical load. The electrical system detects the voltage leak and trips the circuit breaker to prevent fire or electrical shock.

Lengthy Extension Cords

• In the same vein, long extension cords -- even if the cord gauge is sized properly with the chop saw -- may trip a circuit breaker. Electrical transmission is sensitive to distance. The further the distance, the higher the electrical resistance and the greater the voltage drop. Therefore, despite correct sizing, extremely long extension cords are unable to provide the large amount of voltage required to run the power tool. The electrical system and the chop saw seek to equalize the dropped voltage transmission and try to increase the load, overheating in the process. When the circuitry of the building senses the disruption, it trips the breaker as a safety measure.

Chop Saw Performance

• A small chop saw may require 12 amperes (amps), while a heavy duty saw needs 15 amps or more. Connected to a long extension cord, the chop saw attempts to pull more power to operate the motor. Unable to do so, the saw and the extension cord become hot with the effort. The chop saw wires inside the motor may overheat to an extent that the wires melt, causing irreparable damage or early failure to the machine. The circuit breaker senses the electrical strain and breaks the electrical connection to prevent overheating or fire.

Accurate and Safe Use

• For safe and efficient chop saw operation, extension cords should be sized appropriately. For heavy-duty electrical power tools such as the chop saw, Appion, Inc., recommends a 12-gauge extension cord measuring no longer than 25 feet, or a 10-gauge cord measuring no longer than 100 feet. Extension cords longer than 100 feet and sized below 10 gauge are incapable of providing the proper amount of voltage to run a 15-amp chop saw. The best practice is to use the largest gauge wire and the shortest length possible when operating the chop saw.