1769-PB4 power consumption

Hello,

I want to ask about the power consumption of the 1769-Pb4: It is written that the input power consumption at maximum load is equal to 100W. However, as I can see from its datasheet http://literature.rockwellautomation.com/idc/groups/literature/documents/in/1769-in028_-en-p.pdf (page 29), the pb4 can supply at 5Vdc 4amps and at 24vdc 2A. Doing a basic calculus, the output power of the pb4 is equal to 68W however its input consumes 100W. why there is a difference between the input power and output(32W)?

Thanks for your help

The output numbers are probably being conservative and there is always wasted energy (mostly in the form of heat) in a power supply.

The power consumption is probably also being conservative (err on the side of caution) in that the supply may draw up to 100W, but in reality in a typical application you will likely measure much less.