Arktic 59 Motors

Arktic 59 Motors are electronically commutated motors (ECMs) manufactured by Morrill Motors, a Regal Rexnord brand, designed primarily for evaporator coils in commercial refrigeration walk-in coolers and freezers. Built in a compact 3.3" diameter frame, Arktic 59 Motors run on 115V or 208-230V single-phase power and deliver peak output up to 74.6 watts at 1550 RPM. ECM technology gives these motors efficiency levels up to three times higher than shaded pole motors and 40% higher than PSC motors, a difference that shows up directly in lower energy bills on refrigeration systems that run around the clock. For contractors specifying or replacing evaporator fan motors in commercial refrigeration, Arktic 59 Motors are a proven ECM-class solution with a track record in demanding cold-storage environments.

KEY SUBCATEGORIES / PRODUCT TYPES

Arktic 59 Motors by Voltage Configuration Arktic 59 Motors are available in two primary voltage configurations to match the electrical supply of the installation. The 115V models, such as the Morrill 5101A and the Genteq 35103, operate within a 90-132V range and are rated at 1/15 HP, 1550 RPM, single phase. The 208-230V models, including the Morrill 5201A and 35203, operate within a 180-264V range at the same 1/15 HP and 1550 RPM ratings. Confirming supply voltage before ordering is the most common step contractors skip, and it's also the most straightforward way to narrow down the right Arktic 59 Motor for a replacement job.

Single-Speed vs. Two-Speed Arktic 59 Models Single-speed Arktic 59 Motors run at a fixed 1550 RPM and cover most standard walk-in evaporator replacement applications. Two-speed models, such as the Morrill 5111A (115V) and 5210A (208-230V), operate at both 1550 RPM and 800 RPM, giving refrigeration systems the flexibility to reduce fan speed during low-load or defrost cycles. Two-speed operation can reduce motor wear and lower energy draw on systems that don't require full airflow continuously. For a straight replacement, matching the speed configuration of the original motor matters, since wiring a two-speed motor into a single-speed circuit won't give the expected results.

Rotation Direction: CW vs. CCW Arktic 59 Motors are available in clockwise (CW) and counterclockwise (CCW) rotation, viewed from the opposite shaft end (OSE). Rotation direction is set by the blade pitch of the evaporator fan and must match the original motor to maintain proper airflow direction through the coil. Reversing rotation on an evaporator fan doesn't just reduce efficiency, it can push warm air in the wrong direction entirely. Always confirm the rotation of the motor being replaced before specifying an Arktic 59 Motor.

ECM vs. Shaded Pole vs. PSC for Walk-In Evaporators Shaded pole motors have historically been the low-cost default for evaporator fan applications, but the efficiency gap between shaded pole and ECM technology is significant. Arktic 59 Motors run at efficiencies up to three times higher than shaded pole motors and 40% higher than PSC motors, a difference that compounds on refrigeration systems cycling 24 hours a day. PSC motors offer a middle ground, but their fixed operating speeds limit how well they adapt to varying load conditions. For walk-in applications where runtime is constant, the Arktic 59 ECM platform delivers measurably lower energy consumption without sacrificing the reliability the application demands.

Physical Construction and Mounting Every Arktic 59 Motor ships with a 3.3" diameter TEAO (Totally Enclosed Air Over) housing, Class B insulation, ball bearings with low-temperature grease, and a 5/16" diameter shaft with flat. Standard mounting uses 0.5" #10-32 studs on the shaft end with a 2.8" bolt circle, with an optional stud configuration on the opposite shaft end available for specific installations. A 24" cord set with molded plug and a shaft water slinger are included. The TEAO enclosure requires airflow over the motor for cooling, which is standard in evaporator coil assemblies where the fan moves air across the motor continuously.

BUYING GUIDE / HOW TO CHOOSE

Selecting the right Arktic 59 Motor starts with four variables: supply voltage, rotation direction, speed configuration, and HP rating. Supply voltage is first, since 115V and 208-230V models aren't interchangeable. Arktic 59 Motors are available at 115V (90-132V operating range) and 208-230V (180-264V operating range), both running single-phase, 60/50 Hz. Rotation direction, viewed from the opposite shaft end, must match the original motor. Swapping CW for CCW on an evaporator fan reverses airflow and can compromise coil performance. Speed configuration is the next variable: single-speed (1550 RPM) covers most standard replacements, while two-speed models (1550/800 RPM) suit systems designed for variable fan operation during defrost or low-load periods. HP rating on Arktic 59 Motors runs at 1/15 HP across most of the lineup, which covers the typical evaporator fan motor specification for walk-in coolers and freezers. For installations asking how to size an Arktic 59 Motor replacement, the safest approach is matching the original motor's nameplate data on all four variables. The 3.3" frame diameter and standard 2.8" bolt circle stud mounting make Arktic 59 Motors a common drop-in replacement across many OEM evaporator coil assemblies, but verifying mounting dimensions against the existing bracket is worth the extra minute before pulling the old motor.

FAQs

What's the difference between an Arktic 59 Motor and a shaded pole motor for a walk-in evaporator?

The difference between an Arktic 59 Motor and a shaded pole motor is efficiency. Arktic 59 Motors use electronically commutated (ECM) technology, which delivers up to three times higher efficiency than shaded pole motors at the same application. On a walk-in system running around the clock, that gap in efficiency directly reduces energy consumption. The Arktic 59 Motor also offers multi-speed capability in select models, which shaded pole motors don't provide.

Can an Arktic 59 Motor replace a PSC motor in a walk-in cooler?

An Arktic 59 Motor can replace a PSC motor in many walk-in cooler evaporator applications, provided the voltage, rotation, HP, and mounting dimensions align with the original motor's specs. Arktic 59 Motors run at 40% higher efficiency than PSC motors, so the replacement reduces energy draw. Confirming that the TEAO enclosure requirement is met, meaning the motor receives continuous airflow in the installation, is a necessary step before completing any PSC-to-Arktic 59 swap.

Which Arktic 59 Motor is right for a 208-230V walk-in freezer evaporator?

For a 208-230V walk-in freezer evaporator, Arktic 59 Motors rated for 208-230V operation, such as the Morrill 5201A or the 35203, are the appropriate starting point. The 208-230V Arktic 59 models operate within a 180-264V range and run at 1/15 HP, 1550 RPM, single phase. Rotation direction still needs to match the original motor, so confirming CW or CCW before ordering remains necessary regardless of voltage.

What does two-speed operation on an Arktic 59 Motor mean for a refrigeration system?

Two-speed operation on an Arktic 59 Motor means the motor can run at either 1550 RPM or 800 RPM depending on the signal from the refrigeration control system. The lower speed, 800 RPM, is used during low-load periods or defrost cycles to reduce airflow and lower energy consumption. Two-speed Arktic 59 models, like the Morrill 5111A (115V) and 5210A (208-230V), require a control system wired to send the appropriate speed signal. Dropping a two-speed Arktic 59 Motor into a system without two-speed control capability won't unlock variable operation.

What mounting hardware does an Arktic 59 Motor use?

Arktic 59 Motors use a standard 0.5" #10-32 stud mounting configuration on the shaft end, with a 2.8" bolt circle. An optional stud configuration on the opposite shaft end is available on select models for installations where end mounting is required. The 3.3" diameter frame and standard stud layout make Arktic 59 Motors a common drop-in fit across many OEM evaporator assemblies, but verifying the existing bracket dimensions against these specs before installation prevents clearance issues