Five Two One® (521) — Hard Start Kits & Capacitors for Reliable HVAC Performance
Five Two One — also known as 521 — designs industry-leading hard start kits and compressor protection components that improve HVAC system reliability and performance. Available now at HVACProSales.com, these 521 Compressor Saver® kits help reduce stress on air conditioner and heat pump compressors during startup, extending equipment life and reducing maintenance costs.
Each 521 hard start kit combines a PTC relay, start capacitor, and run capacitor to deliver extra torque when the compressor motor starts under heavy load. The result is faster startups, lower amp draw, and improved efficiency — especially beneficial for aging or high-SEER systems operating in hot, humid environments. Installation is simple and compatible with most residential and light-commercial units.
Trusted by HVAC technicians nationwide, Five Two One hard start kits provide a cost-effective way to enhance performance, prevent premature compressor failure, and save energy. Whether you’re performing preventive maintenance or troubleshooting system failures, 521 products deliver dependable results every time.
- Hard start kits designed for air conditioners and heat pumps
- Compressor Saver® systems with prewired components
- Reduces inrush current and extends compressor life
- Easy-to-install kits for professional HVAC service
Five Two One® — Hard-Start Kits & Components
Boost compressor start-up and reduce light-dimming with proven hard-start and protection components.
Faster Starts
Helps compressors overcome initial torque.
Protection
Components designed for longevity.
Compatibility
Solutions for common tonnages.
Service Stock
Keep kits ready for no-cool calls.