Hello,
the label on the power supply (hopefully) shown below says:
"Caution! Intended for installation in a protected environment."

What is meant by the word installation? Does it mean that the power supply must be mounted with screws using the fixtures on both sides of the unit or can it also be laid on the floor behind the machine it supplies (office printer)?

<img src="http://home.arcor.de/pengquadrat/PowerSupply-s.jpg" alt="Caution! Intended for installation in a protected environment.">