... National Standards Explosion Proof Motor, Flameproof Motor, Electric Motor, Asynchronous MotorYB2 series Explosion proof electric motor are designed and manufactured into explosion proof type and the explosion proof property conforms ... sea level. 3.Relative humidity should be less than 90%. Explosion Proof Motor, Flameproof Motor, Electric Motor, Asynchronous Motor,(with IMB5 Flange)