When you're selecting an industrial motor, the first question is not brand - it's power delivery. The motor has to match the voltage and phase of your shop, the speed range of your equipment, and the environment it will live in. In this head-to-head, we're looking at two very different AC motors: a Baldor-Reliance general-purpose motor and a mek 5HP air compressor motor. One is a compact 3-phase helper, the other is a single-phase workhorse aimed at continuous compression. Both are new, both are AC, and both operate at 60 Hz, but they go about their jobs very differently.
Quick verdict
If you're outfitting an air compressor and you have single-phase 208-230V service, the mek 5HP is the motor to buy: it's purpose-built for continuous compression work, with the horsepower and frame size to handle the load. If your shop has 3-phase power and you need a lower-priced helper motor for light duty in a dusty environment, the Baldor-Reliance is the sensible pick. The Baldor lists at $275.00, the mek at $449.99, and that price gap reflects the difference in capacity and intended use.
Comparison table
| Feature | Baldor-Reliance CNM3457 | mek 5HP Air Compressor Motor |
|---|---|---|
| Price | $275.00 | $449.99 |
| AC Phase | Three Phase | Single Phase |
| Base RPM | 3450 | 1750 |
| Enclosure Type | TENV (Totally Enclosed Non-Ventilated) | TEFC (Totally Enclosed Fan Cooled) |
Where each product wins
The Baldor-Reliance is the pick when the working area is filled with dust, dirt, or light moisture and you need a compact, dependable AC motor. Its TENV enclosure means there are no external fan openings, so grit has a harder time getting inside. The mek is the pick when your task is air compression: its TEFC enclosure uses a fan to keep it cool during long runs, and its design is matched to single-stage and two-stage compressors. If you're building or repairing a compressor, the mek gives you the purpose-built foundation you want.
Product notes
Baldor-Reliance CNM3457 3-Phase General-Purpose Industrial AC Electric Motor
The Baldor-Reliance CNM3457 is a light-duty, general-purpose machine. It spins at a fast 3450 RPM, which suits single-speed applications like fans, pumps, or conveyors. Its condition is new open box, meaning it is essentially new but the packaging has been opened. With an output of 0.33 HP and a full-load amperage of 1.6-1.4/.7 amps, this motor is not designed to turn a heavy compressor or a big industrial load. Instead, think of it as a reliable helper motor for auxiliary equipment in a shop where dust and light moisture are present. Choose it when you need a compact AC motor that can live in a gritty environment and run at a high speed. If you need more horsepower or a simpler power hookup, this motor won't be the right fit.
mek 5HP 1750RPM Air Compressor Electric Motor 184T Single Phase TEFC 208-230V
The mek Air Compressor Electric Motor is a purpose-built machine for compressor duty. It turns at 1750 RPM and delivers 5HP on a 208-230V supply. That power comes with a 28.5-27A full-load draw, so make sure your circuit and wiring are sized for that current. The motor uses a TEFC (totally enclosed fan cooled) enclosure, which helps it handle heat during continuous runs, and it carries an IP54 rating for dusty or outdoor installation. It's built with a rolled steel shell and is designed for single-stage and two-stage air compressors and agricultural equipment. If you're replacing a failed compressor motor, this is the one to choose.
Final choice by use case
If your task is air compression, go with the mek. If you need a light-duty motor for a dirty environment and already have the right power feed, the Baldor-Reliance works well. Matching the motor to your power supply and load type is the key to a trouble-free installation.
