Menu
Menu
Totally Enclosed Fan Cooled or Open Drip Proof — the wrong enclosure in the wrong environment cuts motor life by half or more. Here’s the plain-English guide to picking correctly.
| Attribute | TEFC (Totally Enclosed Fan Cooled) | ODP (Open Drip Proof) |
|---|---|---|
| Housing | Sealed; external fan cools by blowing air over housing fins | Ventilated housing; internal fan pulls ambient air through the motor |
| Dust ingress protection | Excellent — sealed against most industrial dust | None — dust enters freely; will accumulate on windings |
| Moisture / splash protection | Good — sealed against splashes from above & sides | Only protection is from vertically-dripping water; splashes get inside |
| Cooling efficiency | Lower — heat must transfer through housing walls; larger frame for same HP | Higher — direct airflow through motor; smaller frame for same HP |
| Noise | External fan is louder; ~60–70 dB typical | Quieter — internal airflow with less fan noise; ~50–60 dB typical |
| Ambient temperature tolerance | Excellent up to 40°C; derate above that | Very good, but if ambient air is dusty/humid, you’re pumping that into the motor |
| Cost (like-for-like HP) | 10–20% more than ODP | The cheaper choice |
| Maintenance | Low — no interior cleaning | Higher — requires periodic blow-out to prevent dust buildup |
| Typical use | Industrial floors, outdoor, dusty, moist environments | Clean, dry, indoor climate-controlled rooms |
• Outdoor installation.
• Any dust, sawdust, grain, textile lint, or metal dust in the air.
• Wet or humid environment (paper mill, water treatment, food).
• Industrial floor with any risk of splashes or spills.
• Farm barn, agricultural setting.
• Unknown / mixed conditions — TEFC is the safe default.
• Clean, dry, indoor climate-controlled room.
• Cost is the primary driver on standard-duty application.
• Noise level matters (ODP is quieter).
• Pump room or utility room with good ventilation and no contamination.
• Never for outdoor, farm, or process industry use.
Rule of thumb: Unless you have a specific reason to save money on an indoor clean environment, always go TEFC. The lifetime cost of a dust-damaged ODP motor exceeds the enclosure premium many times over.
| Enclosure | What it adds | Typical use |
|---|---|---|
| TENV | Totally enclosed, non-ventilated — no external fan. Cools by radiation only. | Very low HP; quiet applications; small servos |
| TEAO | Totally enclosed air over — relies on process airflow (fan blade, etc) | Direct-drive fan motors that use the fan itself for cooling |
| WPI / WPII | Weather-protected — open motor with baffles that block direct rain | Large motors (200+ HP) outdoors; alternative to TEFC at scale |
| Washdown Duty | TEFC + food-safe finish + sealed shaft — withstands high-pressure spray | Food, beverage, pharma processing |
| Explosion-Proof (XP) | TEFC + contains internal explosion so external atmosphere doesn’t ignite | Class I / II hazardous locations (see our XP guide) |
Describe the location and application — we’ll recommend the right enclosure so you’re not paying too much or too little.
Filter by exact spec for replacements.
Guides, charts, spec references.
Technical guides from our experts.
