piglet wrote:..."How do you mount or enclose something like this to ensure it's safe?" The 240v connections seem to be exposed, or occasionally covered with a flip-down piece of plastic....
...I'm surely not the only person flummoxed on how to safely use such a thing around the house.
This is an instrument power supply, which has to be designed into a system. It is not a component to be used around the house.
Any plastic tags over the mains terminals are simply there as an additional safety measure for anyone working on the equipment when "live" and exposed. But normally neither these contacts, or the power supply case itself would be accessible to a user.
I'm not sure why you would expect there to be information on how to safely install this component into a system, anymore than you would for other high voltage components that are available, such as 240V relays or mains transformers.
Looking at the example illustrated, the whole thing needs to go into an enclosure, as you wouldn't want a child to poke metal objects through the grill or come into direct contact with the wires or terminals at mains potential.
Since the power supply case has lots of holes, the components inside probably need plenty of air-flow. So if put inside a totally sealed enclosure, the enclosure needs to be of an adequate size and may need to be metal to conduct the heat away (this info may be deduced from the specification). Note that fitting a fan inside a closed box will only help cool the component if the box is large enough to conduct the heat away from its surface fast enough.
The cable connecting the supply to the mains needs to have a current rating higher than the power supply input current rating. The fuse used in the mains plug must have a rating lower than the mains cable rating. The mains fuse is there to protect the cable, not the power supply (i.e. it is important that the mains fuse blows before the insulation on the mains cable starts to melt).
The cable must be adequately clamped inside the enclosure so that if pulled, the terminating wires are not strained (i.e. adequate strain relief).
If the enclose in conductive (metal) it must be connected to earth.
This is not an exhaustive list. It is just to warn you that you can't just hang a few wires onto a chassis power supply and leave it laying around your house.
I hope this helps.