TL;DR
Voltage drop is the loss of electrical potential along a conductor as current flows through its resistance, leaving less voltage at the far end of a circuit than at the panel. It grows with wire length and load and shrinks with conductor size, which is why the NEC recommends sizing so branch circuits lose no more than 3 percent, 5 percent total with the feeder.
What it means
Voltage drop is the loss of electrical potential along a conductor as current flows through its resistance, leaving less voltage at the far end of a circuit than at the panel. It grows with wire length and load and shrinks with conductor size, which is why the NEC recommends sizing so branch circuits lose no more than 3 percent, 5 percent total with the feeder. The practical symptoms are dimming lights when motors start, sluggish well pumps and EV charging at the end of long runs, and detached garages that need heavier feeders than their breaker rating alone suggests.
Where it sits in the glossary
Voltage drop is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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