Applications:various operation systems by which speed-regulation is needed,such as metallurgy, chemistry, textile, pumps, machine tool,etc. Protection Class:IP54,/Insulation Grade:F,Cooling Way：B，Duty Type:S1 Features： Step-less adjustable speed operation in a wide range Good performance of the system,energy saving.High-grade insulation material and special technological With stand high frequency pulse impact.Separate fan for forced-ventilation