Technical Explanation The premise of using top-mounted fan: Ambient temperature should be lower than the temperature that is required to be in the switchboard. Take top-mounted fan into account, when there isn’t enough space for a side-mounted filter fan in the cabinet. Top-mounted fan of the cabinet will bleed the air from the top of the cabinet and drive the heat out so as to protect the electric apparatus and keep them running at the temperature within controllable ranged. And the structure is more proper because it won’t take up space in the cabinet. EN 60 529/10.91 reaches IP54. The retractable high-power centrifugal fan is able to prevent moisture as well as mechanical damage, with its labyrinthine rain-proof structure, which with the help of the sealing frame, can reach an IP code up to IP54 as per EN60529/10.91. The centrifugal fan is mainly useful for discharge of high-heat load at peak efficiency. Adoption of the centrifugal fan will be able to reduce the noise resulting from air friction as well as avoiding the vortex discharged by normal shaded pole fan. The quantity and dimensions of inlet filters could be determined according to the actual situation. Please mark B behind corresponding model if a stainless shell required. We can provide products with different voltage as required by clients. Using Lk33 or EF Series Exit Filters at the side of the cabinet can prevent water and dust entering the cabinet, also make the air through the whole cabinet for cooling. Model No. KRF-670 KRF-950 KRF-1410 Voltage Frequency 230V, 50/60HZ Air flow/ Free discharge of air 620/670m3/h 910/950m3/h 1250/1410m3/h Centrifugal fan Capacitor Rated current 0.24A/0.31A 0.36A/0.38A 0.58A/0.62A Power 56/72W 82/88W 130/190W Noise level 55/56 dBA 60/62 dBA 65/70 dBA Temperature range -10 ℃~ 55 ℃ The quantity and size of the wind inlet filter can be decided according to the concrete requirement