An electric motor is considered explosion-proof when it is capable of containing an internal explosion without rupturing and putting the entire industrial facility at risk.
What makes a motor explosion proof?
A motor enclosure that withstands and contains an internal explosion. Flame exhaust paths that dampen flames and permit hot gases to escape the enclosure. No surface that exceeds the lowest auto-ignition temperature of the vapor, gas or dust in the anticipated environment.
Is a Class 1 Div 2 motor explosion proof?
While Division 1 motors in Class I locations must be explosion-proof, Class II, Division 1 motors must be dust- ignition-proof. … One important distinction is that the enclosure of a dust-ignition- proof motor is designed to exclude hazardous materials.
Are brushless motors explosion proof?
Explosion proof DC motors can be in any wiring configuration: brushed or brushless, permanent magnet or electromagnetic field. … Limit the maximum temperature of the motors so any flames that happen to escape the motor are cooled to a level that cannot ignite the external environment.
What NEMA is explosion proof?
NEMA 7 Indoor use in locations classified as Class I, Division 1, Groups A, B, C or D hazardous locations as defined in the National Electric Code (NFPA 70) (Commonly referred to as explosion-proof).
How can you tell if a motor is flameproof?
- Service/class temperatures.
- Reference pressure – waveform smoothing at 5kHz.
- Flame path width and gaps.
- Ignition tests with variety of explosive gas mixtures, five tests per mixture.
- Flame transmission.
- Enclosure strength.
- Enclosure must contain explosions at 1.5 times standard explosive pressure.
What are 4 common types of motor enclosures?
The most common types of enclosures are:
- Open Drip Proof (ODP) …
- Weather Protected (WP1 / WP2) …
- Totally Enclosed Fan Cooled (TEFC) …
- Totally Enclosed Non-Ventilated (TENV) …
- Totally Enclosed Air Over (TEAO) …
- Totally Enclosed Forced Ventilated (TEFV) …
- XP (Explosion Proof)
What is the difference between Class 1 Div 1 and Div 2?
Class I locations are those in which flammable vapors and gases may be present. Class II locations are those in which combustible dust may be found.
What is Class I Div II?
Class I, Division 2 or Zone 2 classified locations. An area where ignitable concentrations of flammable gases, vapors or liquids are not likely to exist under normal operating conditions. In this area the gas, vapor or liquids would only be present under abnormal conditions (most often leaks under abnormal conditions).
What is a Class A electric motor?
Class A: Maximum Temperature Rise: 60°C. Hot-spot Over Temperature Allowance: 5°C. Maximum Winding Temperature: 105°C.
Are brushless motors intrinsically safe?
The POST committee consulted with a well known tool manufacturer who confirmed that cordless tools, including models with brushless motors are not intrinsically safe and have the potential to spark. Therefore, hot work protocols must be followed when using cordless tools when working under these conditions.
What NEMA rating is for outdoor use?
NEMA 3: For indoor or outdoor use. Same as NEMA 2 but adds stronger protection against the ingress of water and dust. It protects against windblown dust, rain, sleet, and snow and will be undamaged by ice forming on the enclosure. NEMA 3R: Same as NEMA 3 but without the protection against windblown dust.
What does NEMA 7 mean?
NEMA 7 enclosures are designed to contain an internal explosion without causing an external hazard. These enclosures are intended for indoor use in hazardous locations classified as Class I, Division I, Groups A,B,C, or D.
Is NEMA 4x dust tight?
NEMA 4 is watertight and dust-tight for inside and outdoor applications. NEMA 4X is everything listed, plus corrosion-resistant.