1. centrifugal fan wind chassis, the required electrical power is the condition to be determined, together with proper mechanical loss reserves, it is not a required air full of power, such as the fan outlet is not then pipe or add external resistance and empty running, the motor burned danger, for safety reasons, the valve should be added at the fan outlet or inlet pipe, closed at the start fans, Qujing exhaust fan, running after slowly open the valve, is reached a predetermined condition, and pay attention to fan current exceeds a predetermined value. 2. The fan allows full pressure start or step-down start, but it should be noted that the current full voltage starting time of 5 to 7 times the rated current, voltage starting torque is proportional to the square of the voltage, when there is insufficient grid capacity, should be used voltage starting. (When the power is greater than 11KW, axial exhaust fan, should buck starter). Because the underground chambers by underground limiting factors and space, in the wind and air pressure and other factors of satisfaction coefficient, fire fighting systems and smoke exhaust ventilation is usually used in combination can, therefore, we in the underground garage Use two-speed fan, the same is basically the same fans and the same duct. Under normal circumstances, as the exhaust ventilation fan running at low speed applications, when a fire, fan into a fast run both stand as fire exhaust fan applications. So a machine 2 with not only decrease the cost of health made, save space, more important thing is to greatly enhance the configuration of the application rate and credibility. Should the smoke exhaust and harm are basically two systems left, but the fire exhaust fan only, produce fire bet when running, usually fewer applications, as revealed problems not easily be discovered in time and get the repairs, and real fire when the exhaust fan selection, is not easy to guarantee Hang Shun betting applications. The two-speed fan just to overcome this deficiency, usually as an exhaust fan running, the problem appears to be excavated and get timely repairs, often in a good posture drops ready. 1. Commissioning number less than two, one to control power, one observes fan operation, abnormal phenomenon immediately stop inspection; First check the direction of rotation is correct; fan during each phase of the operation should be checked whether the current balance, current is exceed the rated current; if not normal, you should stop checking. After running for five minutes, the fan down to check whether there is abnormal phenomenon, confirmed that no anomalies start running again. 2. The two-speed fan when the test, two-speed exhaust fan, you should start low, and check the direction of rotation is correct; after resting fan must be renewed at the start speed to prevent reverse rotation speed, causing the switch trips and motor impairment ??? Fire exhaust fan | Chenyu air conditioning (certified) | Qujing exhaust fan by Wu Cheng Chen-yu air-conditioning Limited. Wu Cheng Chen-yu air-conditioning Co. (www.wccykt.com) is an industry leader in Shandong Dezhou, fans, ventilation equipment, over the years, the company implement the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs ??? Chen Yu-conditioned in leadership with the staff warmly welcome all inquiries negotiations to create Chenyu air conditioning better future.