If electrical interference turns out to be a problem, I imagine that you could electrically isolate the control electronics from the holiday detector, and put them inside a screened enclosure. I'm not totally sold on the idea of trying to make this a self-contained system, though. If I was doing this then at least the MK 1 version would have the minimum hardware needed to detect and repair flaws on something that could be pulled through the pipe manually, with hard-wired controls. Replacing the manual pull with a tube crawler and replacing the hardwired controls with remote control can come later if necessary.