Hi,
I have DC system.
The current consumption of the equipments during operation and during rest is known
The type of cable (cross section) used is known
The power supply provided (in Amps) is also known,
I want to know what is maximum cable achieved with this power supply.

What code would you like to use?
How conservative would you like to be?
What is the average temperature? In steel or
pvc Pipe? How many conductors in the pipe?
If you are not specific, we cannot be either...