Meet a dependable, legacy-grade run capacitor built for A.O. Smith/Century systems. The A.O. Smith (AOS) Century Run Capacitor, 7.5 MFD at 370V, in an oval 2" x 2 5/8" footprint (part 628316-312), is a proven replacement that keeps motors running smoothly in residential HVAC, pool and spa equipment, and related applications that rely on precise electrical phase shifting.

Why this capacitor matters

• Exact specification match: 7.5 microfarads (MFD) and 370-volt rating ensure compatibility with original equipment designs and motor start/run circuits.
• Compact oval form factor: 2" x 2 5/8" oval shape fits tight spaces often found in OEM enclosures and compact machinery.
• Direct replacement lineage: Designed to replace older part numbers 17035501, 389887, and R3001100, making it a straightforward upgrade path for legacy systems.
• Historic reliability: From A.O. Smith and Century, now under Regal Beloit, these capacitors have long been trusted in HVAC compressors, pool pumps, and spa equipment for steady, dependable operation.

Important compatibility note

This item is listed as discontinued by the manufacturer. That status reflects its place in legacy installations rather than its performance on the job. If your equipment calls for the 7.5 MFD, 370V run capacitor with an oval 2" x 2 5/8" form, the 628316-312 variant provides a faithful, tested replacement that matches the original electrical characteristics and mounting footprint.

Who this is for

• HVAC technicians servicing home air conditioners and heat pumps that use Century/A.O. Smith components.
• Pool and spa professionals maintaining circulating pumps, jets, and related equipment built around older AOS/Century capacitors.
• Homeowners or facility managers performing DIY maintenance on legacy systems and seeking a compatible, OEM-style replacement part.

Use cases and practical applications

• Replacing a worn or failed run capacitor in an air conditioner compressor circuit to restore proper motor torque and efficiency.
• Maintaining pool and spa equipment where legacy Century/A.O. Smith capacitors regulate motor performance and reliable operation.
• Stocking an informed maintenance inventory for service fleets that regularly encounter older AOS/Century components.

What makes this capacitor different from generic replacements

• OEM-aligned specifications: The 7.5 MFD, 370V rating mirrors the original design intent of A.O. Smith/Century motors, helping prevent compatibility issues and nuisance electrical noises.
• Proven form factor: The oval 2" x 2 5/8" size ensures a snug fit in common electrical enclosures and motor housings — not all aftermarket parts guarantee this exact footprint.
• Replacement continuity: With a direct replacement path for multiple older numbers (17035501, 389887, R3001100), technicians save time and reduce guesswork during service calls.

Tips for a smooth installation and longer life

• Verify the equipment requires a 7.5 MFD, 370V run capacitor and confirm the oval 2" x 2 5/8" mounting format before replacing.
• Carefully disconnect power and discharge any residual charge in the system before handling capacitors.
• Inspect associated motor and wiring for signs of wear, heat, or oil contamination, and replace related components if needed to maximize the capacitor’s lifespan.
• When in doubt about compatibility, reference the OEM part number and the listed replacements (628316-312 replacing 17035501, 389887, R3001100) to confirm a correct match.

Summary: If you’re maintaining legacy A.O. Smith/Century equipment, this 7.5 MFD, 370V run capacitor (628316-312) offers a precise, reliable, and space-efficient solution. Its long-standing use in HVAC compressors and pool/spa systems—paired with proven replacement mappings—helps you keep critical motors running with confidence, even as original manufacturing lines evolve.