The guys from Inside-Hardware taked a look at the Enermax Whisper EG465P-VE (FCA) 431W power supply :
The EG465P-VE FCA is part of the fan speed adjustable series of power supplies that Enermax offers. A lot of people mistake the differences between the EG465P-VE FC and FCA. Essentially they are both rated at 431 Watts, and offer the same amount of output cables, but the cooling features are vary slightly between the two. The FCA model has an adjustable fan speed knob, which is located on the back of the power supply to control the 8CM Fan on the rear. It does not control the intake fan on the bottom of the psu. The FC uses an internal temperture monitor to adjust the speed of the fan. I felt like I needed to clarify this, because Enermax fans are named relatively similiar and sometimes its rather difficult to distinguish between the two. The best way to make sure your getting a FCA is to look for the blue color.