VFD voltage and frequency relationship
VFD (variable frequency drive) technology enables centrifugal machines to operate at off design conditions at 0.50, 0.40 and even at 0.30 kW/ton. As the cooling load decreases, the VFD decreases its output voltage/ frequency, slowing chiller. The result the chiller operates at near full load efficiency for almost the entire operating range and allows the chiller to operate as low as 10% of rated output without experiencing surging.
One VFD system drawback: It increases the chiller's full-load current draw by 5 percent to 10 percent due to internal losses and conversion inefficiencies.
One VFD system drawback: It increases the chiller's full-load current draw by 5 percent to 10 percent due to internal losses and conversion inefficiencies.
