YD 5210-2014 Technical Specifications for 240 V DC Power Supply System Engineering
1 General principles
1.0.1 The 240V DC power supply system (hereinafter referred to as the system) has been used on a large scale in communication and other industries after product standardization. This specification addresses the technical requirements of the system in construction projects design, construction, and acceptance.
1.0.2 This specification is applicable to new 240V DC power supply system construction projects.
1.0.3 Construction projects shall follow national technical policies, regulations and current specifications to ensure the safety of system operation.
1.0.4 The planning and design of the system shall follow the principle of openness, and the system shall be standardized and expandable online.
1.0.5 The overall design scheme and equipment selection shall follow the principle of combining the recent construction scale with the long-term development planning, and carry out technical and economic comparative analysis of multiple schemes according to factors such as construction and development conditions, economic effects, equipment life, possibility of expansion and reconstruction, etc. In order to improve reliability, and strive to reduce construction projects and maintenance costs.
1.0.6 During equipment installation and design, national technical policies must be followed; resources shall be used reasonably; national standards for quake, fire and environmental protections must be implemented..
1.0.7 The main telecommunications equipment used in public telecommunication network in areas with seismic fortification intensity 7 and above (including 7) in China must pass the seismic performance test of (to) the telecommunication equipment.
1.0.8 The equipment certified by the TLC（Tell Certification Center） or other relevant institution in the country shall be used in the project.
1.0.9 In case of any conflicts between code with relevant national standards/norms, laws and regulations, it shall be handled in accordance with the relevant provisions of national standards/norms, laws and regulations.
1.0.10 Under special conditions, a report on fully-discussed reasons and solutions shall be submitted to the competent authority for approval when it is difficult to implement individual provisions of this specification.YD 5210-2014
2 Nouns and terminologies
2.0.1 240V DC Power Supply System
a system with a nominal DC output voltage of 240 V powered by DC
2.0.2 Suspended Mode
a mode in which neither of the positive and negative poles of the system output is grounded
2.0.3 Insulation Monitoring
a system detects the insulation performance of the DC output and the ground to determine whether an grounding fault or insulation degradation has occurred; Alarm will be given in case of fault or insulation deterioration。
