I have a Soundcraft CPS-800 PSU with a 20 foot cable. I want to know if there is an extension cable available so I can locate the HOT noisy supply in another room.
Even better contact me if you have one.
7 Meters (roughly 21 feet) was the longest one we made. You could have a longer one custom made by someone. It might need to have thicker gauge wires to accommodate the longer distance. You would need to know how long you needed it to run so they could do a calculation. It also may be so long that it becomes impractical to do..
As a starting point i would recommend contacting Alex Welti at Creation Audio Labs in Nashville. https://www.creationaudiolabs.com/ Many, many years ago he was our chief service engineer. That said I'm sure there are plenty of others who could take a look at this for you as well