For cabinet centrifugal fans, we are not unfamiliar, the impeller of the equipment is made of high quality galvanized sheet, the main shaft is made of 45# steel after modulation processing, so what are the main roles of the two types of cabinet fans?
Motor external type, can be used for fire smoke exhaust, also can be used for general ventilation. If the two-speed motor is used, the fan can be operated at a low speed and used for general ventilation. In case of fire, it automatically turns into high speed operation, which is used for fire fighting and smoke exhaust. Motor built-in, can only be used for general ventilation. Because the noise of type B machine is lower than that of type A machine, so only when the fan is only used for ventilation, type B machine can be preferred.