This Code is formulated for unifying the design standard of railway electric power system with achieving the target of safety， applicability， reliability， advanced technologies， economic reasonability， convenient operation and maintenance.

This Code applies to design of railway electric power system （excluding traction power supply system） with voltage level of 110 kV and below.

The design of railway electric power system shall accord with national energy policies，take energy-efficiency measures， reduce power consumption， take environment protection and land acquisition into consideration according to local conditions.

The state-of-the-art technologies，new processes，new materials and new equipment adopted in the design shall comply with relevant national and industrial provisions.

Necessary preventive measures shall be taken against hazard inducers and potential safety defects in the design of railway electric power system

The design for railway electric power system shall be in accordance with not only the requirements stipulated in this Code，but also those in the relevant current national standard.