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In the world of HVAC service and replacement, technicians often refer to motors by their physical size rather than their NEMA frame designation. The 5.6 inch condenser fan motor is a perfect example. While the number “5.6” may sound like a simple measurement, it corresponds directly to the body diameter of the widely used NEMA 48 frame motor family. Understanding what a 5.6 inch condenser fan motor is, where it is used, and how to select the correct replacement is essential knowledge for anyone maintaining or repairing air conditioning and refrigeration equipment.
This article provides a clear, technically focused overview of the 5.6 inch condenser fan motor, including its dimensional basis, typical specifications, common applications, how to verify fit, and practical replacement guidance.
When a motor is described as a 5.6 inch condenser fan motor, the number refers to the diameter of the motor’s stator housing—the cylindrical body that contains the windings and core. More precisely, a motor with a 5.6 inch body diameter is almost always a NEMA 48 frame motor, which has a standard body diameter of 5‑5/8 inches (5.625 inches) . In common trade language, this is rounded to 5.6 inches.
The 5.6 inch body size is the dominant format for condenser fan motors in residential and light commercial air conditioning systems. It sits between the smaller 5.0‑inch (NEMA 42 frame) motors found in some compact units and the larger 6.5‑inch (NEMA 56 frame) motors used in heavier commercial applications.
Beyond the body diameter, a standard 5.6 inch condenser fan motor also typically features:
Shaft diameter: 1/2 inch
Shaft center height (from base to shaft center): 3 inches (for foot‑mounted versions)
However, it is critical to understand that shaft length, mounting hole spacing, and overall motor length can vary significantly between different 5.6 inch motors, even though the body diameter is the same.
The 5.6 inch condenser fan motor is available in a wide range of electrical and mechanical ratings to suit different equipment designs. The most common specifications encountered in the field include:
Horsepower ratings typically range from 1/8 HP to 1 HP, with the following being most common in residential and light commercial systems:
1/4 HP
1/3 HP
1/2 HP
Choosing the correct horsepower is important. Undersizing will cause the motor to overload and trip its thermal protector. Slightly oversizing (e.g., using a 1/2 HP motor where a 1/3 HP failed) is generally acceptable, but significantly oversizing may draw unnecessary current.
The rotational speed of a 5.6 inch condenser fan motor depends on the number of poles and the line frequency (60 Hz in North America). The most common speeds are:
1075 RPM – standard for the vast majority of modern residential condensing units
825 RPM – found on older units or applications requiring lower airflow
1100–1140 RPM – used in some commercial or high‑static pressure designs
Matching the original RPM is essential. A motor running too slowly reduces condenser airflow, causing high head pressure, reduced cooling capacity, and compressor stress. A motor running too fast may create excessive noise and potentially exceed the fan blade’s design limits.
5.6 inch condenser fan motors are manufactured for a variety of supply voltages:
115V – older residential systems and small window units
208‑230V – the most common voltage for North American split‑system air conditioners and heat pumps
277V – sometimes used in commercial buildings fed from 277V lighting circuits
460V – industrial and large commercial equipment
Many universal replacement motors in the 5.6 inch size offer multi‑voltage capability, such as 208‑230/460V.
Because these motors are installed outdoors in condensing units, they must be protected from weather and debris. The standard enclosure for a 5.6 inch condenser fan motor is TEAO (Totally Enclosed Air‑Over) , also known as OAO (Open Air‑Over) or OPAO (Open, Protected Air‑Over).
A TEAO motor is not hermetically sealed, but its enclosure prevents falling rain, dust, and insects from entering the internal components. Cooling is provided by the airstream generated by the fan blade attached to the motor shaft. High‑quality TEAO motors include shaft slingers, sealed ball bearings with synthetic grease, and corrosion‑resistant coatings.
The 5.6 inch condenser fan motor is found in a broad range of HVAC and refrigeration equipment, including:
Residential split‑system air conditioners (most major brands, 1.5 to 5 tons)
Residential and light commercial heat pumps (outdoor unit fan)
Packaged rooftop units (light commercial, up to approximately 10 tons)
Commercial refrigeration condensing units (walk‑in coolers and freezers)
In every application, the motor’s role is identical: to drive the fan blade that pulls ambient air across the condenser coil, rejecting the heat absorbed from the conditioned space or refrigerated load.
When a 5.6 inch motor fails, simply matching the body diameter is not enough. Use the following checklist to ensure a correct replacement:
Verify the nameplate voltage of the original motor (e.g., 208‑230V single‑phase). Do not guess.
Match or slightly exceed the original HP. Never install a lower HP motor.
Match exactly. 1075 RPM is the most common, but verify with the nameplate.
Diameter: Almost always 1/2 inch for a 5.6 inch condenser fan motor.
Length: Measure from the motor face (or bearing retainer) to the end of the shaft. Typical lengths range from 6 inches to over 7 inches for condenser fan applications. A shaft that is too short may not fully engage the fan blade hub; a shaft that is too long may interfere with the condenser grille.
5.6 inch motors can be mounted in several ways:
Belly band – a steel strap that wraps around the motor body
Thru‑bolts – long bolts that pass through the full length of the motor
Rigid base – a flat base with mounting holes
Measure the distance between mounting holes or the bolt circle diameter. Many universal replacement motors include multiple mounting adapters.
Determine the original rotation direction as viewed from the shaft end (clockwise or counter‑clockwise). Most universal 5.6 inch motors are reversible by changing lead connections.
Must be TEAO or OAO. Never use an open drip‑proof (ODP) motor in a condensing unit—it will fail quickly from moisture ingress.
Permanent Split Capacitor motors require an external run capacitor. Note the microfarad (µF) and voltage rating from the original motor or capacitor. Common values: 5, 7.5, or 10 µF at 370V or 440V.
The majority of existing 5.6 inch condenser fan motors are Permanent Split Capacitor (PSC) type. PSC motors are simple, affordable, and widely available as aftermarket replacements. They operate at single speed (or two speeds with tapped windings) and rely on an external run capacitor.
However, Electronically Commutated Motors (ECMs) are increasingly common in newer OEM equipment and are available as premium replacement options. A 5.6 inch ECM condenser fan motor offers:
Higher efficiency – typically 15‑30% less energy consumption than a comparable PSC motor
Soft start – reduces mechanical stress on bearings and the fan blade
Built‑in protection – electronic overload and over‑temperature safeguards
Variable or constant‑speed operation – some ECMs can be configured for different airflow profiles
For service replacements, PSC motors remain the most popular choice due to lower upfront cost and universal fit. However, when energy savings or utility rebates are a factor, upgrading to an ECM can be a cost‑effective long‑term decision.
To extend the life of a 5.6 inch condenser fan motor:
Keep the condenser coil clean – A dirty coil raises head pressure, making the motor work harder and run hotter.
Inspect the fan blade – A bent, cracked, or unbalanced blade will cause vibration that destroys bearings.
Replace the run capacitor proactively – A weak capacitor is a common cause of motor overheating and failure.
Listen for bearing noise – Grinding or squealing indicates bearing wear; replace the motor before it seizes.
Properly maintained, a quality 5.6 inch condenser fan motor can last 10 to 15 years in typical residential service.
The 5.6 inch condenser fan motor—better known as the NEMA 48 frame—is the industry standard for residential and light commercial condensing units. While the 5.6 inch body diameter is consistent, successful replacement requires attention to shaft length, mounting configuration, horsepower, RPM, voltage, enclosure type, and rotation direction.
Whether you are a technician replacing a failed motor or a facility manager planning spare parts inventory, understanding these details ensures that you select the correct component, avoid return trips, and restore system performance quickly. By respecting both the electrical specifications and the physical dimensions of the 5.6 inch motor, you can keep air conditioners, heat pumps, and refrigeration systems operating reliably through even the most demanding cooling seasons.
