Thanks for the welcome and I think I have figured out the problem. I was looking for the power settings and packages responsible for screen time out settings until I found this post https://unix.stackexchange.com/questions/329893/screen-turns-off-after-10-minutes-and-i-cant-find-out-why
In short, adding xset -dpms & and xset s off & to bspwmrc stop the screens turning off automatically after 10 minutes idle.