Description
4 HP 1-Phase Thru-Bolt Motor, 56Y Frame, 3450 RPM – B237
Upgrade to a dependable single‑phase drive with the 4 HP B237 motor. Built for 230–240V systems and through-bolt mounting, it’s a practical retrofit for HVAC, pumps, conveyors, and small machine tools.
- Power & Speed: 4 HP, 2‑pole design delivering 3450 RPM at 60 Hz for steady torque and smooth operation.
- Voltage & Phase: 230–240V, single‑phase operation compatible with standard home, commercial, and light industrial circuits.
- Frame & Mounting: 56Y (56J) frame with thru‑bolt mounting for rigid, aligned installation under heavy loads.
- Shaft & Coupling: Threaded shaft simplifies coupling to belts, pulleys, or gear assemblies.
- Protection: Auto overload protector guards against overheating during peak demand.
- Footprint: Compact 13.33 inches in length to fit tight enclosures and retrofit spaces.
- Current: Full-load current around 12 A, suitable for common 230V circuits.
- Brand & Reliability: From A.O. Smith / Century Electrical, delivering trusted performance and durable build quality.
Ideal for a range of demanding single‑speed drives, this motor excels in HVAC blowers and air handling equipment, water or sump pumps in residential and light commercial settings, conveyors and material handling, as well as industrial fans and small process equipment. Its single‑speed design keeps drive control simple and dependable in continuous‑duty applications, while the thru‑bolt footprint and threaded shaft support precise alignment and robust coupling in constrained spaces. Before wiring, ensure a 230–240V supply and that controllers and breakers are rated for at least 12 A FLA. Tighten mounting hardware to spec to maintain alignment under load.
Upgrade to a dependable single-phase drive with the 4 HP Motor 1 Spd 12A 240V (56Y) Thru-Bolt, model B237. Built around a classic 56-frame footprint and designed for robust, through-bolt mounting, this motor is ready to replace aging drives in a wide range of equipment.
With a two-pole design delivering 3450 RPM at 60 Hz, it powers fans, pumps, conveyors, and small machine tools with consistent torque and smooth operation. The 230–240V operating range and a steady 12 A full-load current make it a practical retrofit for existing 230/240V circuits and new installations alike.
Key advantages you’ll appreciate:
- Thru-bolt mounting provides a sturdy, aligned installation that resists misalignment during heavy loads.
- Threaded shaft simplifies coupling to belts, pulleys, or gear assemblies.
- Auto overload protector (C) safeguards the motor from overheating during peak demand.
- Compact footprint with a dimension of 13.33 inches, fitting into tight enclosures.
- Single-speed operation keeps drive control simple and reliable in continuous-duty applications.
- Frame compatibility supports 56J designation (56Y), ensuring broad compatibility with common equipment footprints.
Ideal applications
This 4 HP, 2-pole, single-phase motor is well-suited for:
- HVAC blowers and air handling equipment
- Water pumps and sump pumps in residential, commercial, or light industrial settings
- Conveyor and material handling systems with modest torque requirements
- Industrial fans, blowers, and small process equipment
Installation and safety notes
Before wiring, verify your supply is in the 230–240V range and that your controller and circuit breakers are rated for at least 12 A FLA. Use properly rated couplings and belts for the threaded shaft, and ensure the thru-bolt mounting hardware is tightened to spec to maintain precise alignment under load.
Why choose this motor
Unlike generic replacements, this motor is purpose-built for reliability in single-speed, 2-pole drives with a through-bolt footprint, offering trouble-free retrofits and long service life in demanding environments. The combination of a robust auto overload protector, threaded shaft, and a compact 13.33" length makes it a practical, durable choice for upgrading existing equipment or selecting a proven motor for a new build.
Ready to install in your next project—order model B237 today and experience dependable performance in demanding single-phase drives.

