Fan motors in Ex d, Ex e, Ex p, Ex n and Ex tD types of protection for ventilation fans at filling stations, underground mines and chemical plants.
Explosion-Proof Fan Motor
An explosion-proof fan motor is not an ordinary motor in a thick casing: its job is to prevent ignition. It does so either by keeping internal sparks and hot surfaces from reaching the outside, or by not allowing any ignition source to arise in the first place.
Types of protection: Ex d (flameproof) is the most common; parts that may spark are enclosed in an explosion-resistant housing. Ex e (increased safety) prevents sparks and excessive temperatures by design. Ex p (pressurised) keeps the enclosure at positive pressure with clean air or inert gas. Ex n (non-sparking) produces no ignition source in normal operation. Ex tD is designed for explosive dust atmospheres such as grain, wood and flour plants.
A marking such as "Ex db IIC T4 Gb" on the motor defines the type of protection, the gas group (I for mines; IIA / IIB / IIC for other gases) and the temperature class (T1 – T6). The values below belong to a 160 kW 2-pole model delivered to a customer in Vietnam.
- Applications — coal mines, petrochemicals, town gas, grain and oil processing, paint, pharmaceuticals, textiles and metallurgy
Technical Specifications
| Sample model | YE3-315L-2, 160 kW |
|---|---|
| Voltage / frequency | 415 V, 50 Hz |
| Current | 284 A |
| Speed | 2,950 rpm |
| Efficiency / power factor | 96.3 % / 0.89 |
| Ex marking | Ex d IIB T4 Gb |
| Protection / duty | IP55 / S1, service factor 1.0 |
| Insulation / temperature rise | class F / class B |
| Frame / altitude | 315 / up to 1,000 m |
