Electrical Fault CheckHome electrical diagnostics

DIAGRAM

Extension cord voltage drop

A cord that is too thin or too long for the load drops voltage along its length: the tool sees low voltage and the lost energy turns into heat in the cord. Round-trip drop is 2 × length × current × resistance-per-foot.

source-governed Diagnostic estimate. Not a quote, not a substitute for a licensed electrician. source pack dated 2026-06-20 · authority hashes pending
VOLTAGE DROP too thin / too long → low voltage at the tool>3–5% drop120 Vlow Vheat in cord
Where to stop. Choosing or replacing an extension cord is homeowner-safe. Manufacturers and fire authorities advise plugging high-draw heating appliances such as space heaters directly into a wall receptacle rather than any extension cord. Anything involving the building's wiring or circuit rating is a licensed electrician's job. This is general information, not a quote and not a substitute for a licensed electrician.