Primary substation control cable schedule

[AlbertAllotey]

hello everybody. I need help with some basics about coming up with the cable schedule for a typical 33/11kV primary substation.I've been assigned to supervise a substation construction project and i'm finding some difficulty following what is been done,especially on the control wiring. I asked and the technicians and they couldn't give me clear explanations of what they are doing.
I need some help with any literature available to help with the basic concepts and also some practical literature as well.. Thank you!!