When you're choosing an industrial motor, the first decision is often between single-phase and three-phase power. That choice shapes everything else-voltage, enclosure, and the kind of equipment it can drive. Here, we compare the Baldor-Reliance CNM3457 3-Phase General-Purpose Industrial AC Electric Motor with the Single Phase 5HP SPL Air Compressor Electric Motor. One is a three-phase TENV motor for dusty environments; the other is a single-phase open drip-proof motor aimed at air compressors. Your pick depends on your power supply, the duty cycle, and the environment the motor will live in.
Quick Verdict
Choose the Single Phase 5HP SPL Air Compressor Electric Motor if you're replacing a 5HP single-phase compressor motor and need a 56-frame, 5/8-inch keyed shaft with CW/CCW rotation. Choose the Baldor-Reliance CNM3457 if you have three-phase power and need a totally enclosed non-ventilated motor for a relatively low-horsepower, single-speed task.
At a Glance
| Feature | Baldor-Reliance CNM3457 | Single Phase 5HP SPL |
|---|---|---|
| Price | USD 275.00 | USD 141.88 |
| Phase | Three Phase | Single Phase |
| Voltage | 208-230/460 V | 230V |
| Speed | 3450 RPM | 3450 RPM |
| Enclosure | TENV | ODP |
| Horsepower | 0.33 HP | 5HP |
Where the Baldor-Reliance CNM3457 Shines
This motor is best suited to environments with heavy dust, dirt, and light moisture, thanks to its TENV (Totally Enclosed Non-Ventilated) enclosure. It draws just 1.6-1.4/0.7 amps, which tells you it's a low-power option. The three-phase design runs on 208-230/460V, making it a flexible choice for industrial settings with three-phase service. It's a new open-box unit, too.
Where the 5HP SPL Compressor Motor Shines
This motor is built specifically for air compressor duty, with a 56 frame and a 5/8-inch keyed shaft that's 1.88 inches long. It runs on single-phase 230V, which is common in workshops and garages. The CW/CCW rotation (factory set to CCW) adds flexibility for belt orientation. And at $141.88, it's the more accessible price point.
Product Notes
Baldor-Reliance CNM3457 3-Phase General-Purpose Industrial AC Electric Motor
The TENV enclosure is the main reason to choose this motor. Since it's totally enclosed and non-ventilated, it seals out heavy dust, dirt, and light moisture without requiring ventilation. That makes it a dependable option for a dusty shop floor or a single-speed industrial application. On the downside, the 0.33 HP output is quite low, so it's not meant for high-torque tasks. Also, it's an open-box new item, meaning the original packaging isn't sealed, though the motor itself is new. If your application needs more muscle, this horsepower won't stretch far.
Single Phase 5HP SPL Air Compressor Electric Motor
This motor is designed for air compressors, and it delivers 5HP on standard single-phase 230V power. The 56 frame and 5/8-inch keyed shaft with a 1.88-inch shaft length are typical for compressor replacement duty. It also gives you both CW and CCW rotation, with the factory set to CCW, so you can match existing belt configurations. The trade-off is the ODP (Open Drip-Proof) enclosure, which doesn't offer the same dust and moisture protection as a TENV motor. That makes it better suited to a clean, dry compressor room than a dirty industrial environment.
Final Choice by Use Case
If you need a sealed, three-phase motor for a dusty location and your power requirement is low, the Baldor-Reliance CNM3457 is the better fit. If you're replacing a 5HP single-phase air compressor motor and want rotation flexibility, go with the Single Phase 5HP SPL Air Compressor Motor. Both operate on 60Hz AC, but your phase and enclosure requirements will steer you to the right one.
