TL;DR
A run capacitor is the oil-filled cylindrical capacitor that stays in a motor's circuit continuously, shifting the phase of current in the auxiliary winding so compressors and fan motors run with usable torque and decent efficiency. HVAC condensing units typically use a dual version—rated in microfarads such as 45/5 at 440 volts—serving compressor and fan from one can.
What it means
A run capacitor is the oil-filled cylindrical capacitor that stays in a motor's circuit continuously, shifting the phase of current in the auxiliary winding so compressors and fan motors run with usable torque and decent efficiency. HVAC condensing units typically use a dual version—rated in microfarads such as 45/5 at 440 volts—serving compressor and fan from one can. Heat and age dry them out, and a bulged top or out-of-tolerance reading is the single most frequent fix on summer no-cool calls.
Where it sits in the glossary
Run capacitor 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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