YWF series axial fans are external rotor motors. These motors have characteristics of compact structure, convenient installation and high efficiency etc. YWF series external rotor motors have two kinds, single phase asynchronous operation and three phases asynchronous operation. They are suitable for commercial freezer and cold storage room, ice machine, air cooling machine, water chiller, condensing unit, central air-conditioning and heater, etc. YWF series 100% speed control motor with low starting current. The insulation class of motor is B or F, and the protection class is IP54. All motors have thermal protector in the winding. Voltage: The voltage of the single phase motor is 120V/60Hz, 220V/50Hz. The voltage of three phases motor is 380V/50Hz, we can also supply other fan motors with connection box for clients' choices. YWF fans can be controlled speed by frequency transformer or voltage inverter, three phases fans can be adjusted double-speed by Y/? exchange, or variety speeds by different connection.The axial fans are available with fan guard grill and without guard grill, operating with 200mm to 900mm diameter fan blades. We can offer different installation ways like cylinder (inlet ring), wall ring plate, round frame, etc. We can supply the fan motors with capacitor box or electrical wire for clients’ choices. The standard length of electrical wire on the 800 and 900mm is 1.5m. The service life of motors is more than 30,000 hours. The useable ambient temperature is from -30'Cto 60'C. Before operating the motor, make sure to put the earth wire of the motor connected with the external grounding device. Most of External Rotor Motors have passed UL approval in America, RHOS, CE approval in Europe and CCC safety certificate in China.