Wired Video (Door) Intercom - how to wire power?

[Voltaire]

Hi all. I'm looking at a wired intercom system for the front door. For example, the Futuro series 4 (). I see that it comes with a DC power supply for each monitor. On this demonstration step-by-step by Bunnings they have the DC wire hanging from the monitor down the wall, presumably to a power socket below (). But that looks really tacky and I'd rather go up through the cavity wall to a socket in the roof space. Has anyone installed a wired system like this? How long are the DC wires? Would it need to go into a power circuit, or would a lighting circuit be ok? Thanks.

[mtv]

Typical plug-in power supplies have cables 1.5m-2m in length.

You can extend them with a cable with matching plug/socket, or splice a longer section in-between.

When extending the cable, it's wise to use a larger gauge wire than the original to lessen the voltage drop over longer runs.

The plugpacks should be plugged into a power outlet on a power circuit, not lighting.

A separate 12VDC transformer such as a DIN Rail type used for doorbells and commercial intercoms etc could also be substituted for the plug-in ones supplied.

[Voltaire]

Thanks for the thoughts. I'm worried 1.5m wouldn't be enough, but 2m should be fine to get into the roof. I was told once by a lighting retailer (at the height of the home insulation issue) DC power supplies need to be attached to the vertical beams and away from insulation to prevent fire. I've done this for all the DC-powered downlights. Will look to do same for this.