In hazardous environments, it is very important to choose the right explosion-proof motor with the right protection method. The EX-d and EX-tb certifications indicate different types of protection, each designed for specific hazardous conditions.
EX-d (Flameproof Enclosure)
Definition:
EX-d stands for “Flameproof Enclosure”. The motor is designed to contain any explosion that occurs in its enclosure (the enclosure of the environment inside the electric motor where the rotor and stator and the interior of the terminal box are located) and ensure that flames or hot gases do not escape. Igniting the external environment.
Application:
EX-d motors are typically used in environments with explosive gases or vapors, such as oil and gas installations, chemical plants and refineries.
Key Features:
Designed for environments classified as Zone 1 or Zone 2 (gas or vapor hazards).
Robust enclosures capable of withstanding internal explosions.
Prevents the escape of flame, spark or heat from the motor enclosure.
Examples of use:
Oil rigs with methane or hydrogen gas.
Chemical processing plants with volatile vapors.
EX-tb (dust ignition protection)
Definition:
EX-tb refers to “dust ignition protection by enclosure”. These motors prevent the ignition of combustible dust by ensuring that dust does not enter the motor enclosure and by limiting the surface temperature to safe levels.
TUBE RAEL series electric motors are specially designed for fans and can also be ordered with EX-tb certification.
Application:
EX-tb motors are used in environments with explosive dust such as grain silos, sugar mills and woodworking facilities.
Resistance to dust penetration is an important feature of electric motors
Key features:
Designed for environments classified as Zone 21 or Zone 22 (dust hazards).
Dust-proof enclosures that prevent dust from entering.
Surface temperature is controlled to prevent ignition of dust layers.
Examples of use:
Cement plants with the presence of heavy dust.
Chemical and oil plants that are themselves located in places with a lot of dust and dirt.
Ventilation fans that are directly connected to the blades must be EX-tb.
Conclusion
The choice between EX-d and EX-tb depends on the specific type of hazardous environment:
Use EX-d motors in areas with explosive gases or vapors.
Use EX-tb motors in areas with combustible dust.
Understanding the distinctions ensures compliance with safety standards and minimizes operational risks in hazardous locations.
