Single-line diagram (SLD) is a simplified notation for representing a three-phase power system. It is include some  electrical elements such as circuit breakers, transformers, capacitors, bus bars, and conductors are shown by standardized schematic symbols.

SLD is an important drawing for designing and manufacturing switchgear. 
We can design it , We can assembly it. 

Knkong can design and assembly switchgear as customer's SLD