3 Large/Medium-sized Data Center Rack Power Systems
For large/medium-sized data center rack power systems, considering that their power input is mainly drawn from external large/medium-sized UPS systems, the focus should be on power distribution devices, specifically rack PDUs. A PDU, or Power Distribution Unit, is a device that distributes or manages power. Power distribution refers to the allocation of current, voltage, and interfaces, while power management includes switch control (including remote control), monitoring of various circuit parameters, line switching, load limits, power socket matching and installation, cable management, space management, surge protection, and polarity detection. Since almost all IT equipment in data centers is already or will be placed in standard racks, PDUs, as essential rack accessories, are receiving increasing attention from all parties involved. Fundamentally, a PDU is a type of plug/socket, and therefore, it is subject to relevant industry regulations.
3.1 PDU Classification and Related Standards. Power plugs/sockets are divided into two main categories: industrial use and household and similar use. Household and similar use plugs and sockets are plugs and fixed/mobile sockets used indoors or outdoors for household and similar purposes, for AC power only, with a rated voltage of 50V or higher but not exceeding 440V, a rated current not exceeding 32A, and with or without a grounding contact. This category covers: plugs and sockets including: single-phase two-pole plugs, sockets, and appliance sockets; single-phase two-pole plugs, sockets, and appliance sockets with grounding; and three-phase plugs and sockets. PDUs are classified under Category B, “Household and Similar Use”.
3.2 Specialization
Most countries in the world have their own standards for “plug and socket types, basic parameters and dimensions,” that is, the styles and standards of power plugs and sockets in their own country (region). For example: A. GB1002-1996 “Types, basic parameters and dimensions of single-phase plugs and sockets for household and similar purposes” standard defines the styles and standards of plugs and sockets in China; B. BS1363 defines the styles and standards of plugs and sockets in the United Kingdom (Commonwealth countries basically adopt the British BS standard).
3.3 Universality
The first part of the “Plugs and Sockets for Household and Similar Purposes”: General Requirements, adopted by various countries and regions worldwide, is equivalent to the IEC 884-2-1 standard. This means that the “General Requirements” are essentially the same across countries (except for minor modifications in a few chapters). The “General Requirements” specify the technical requirements and test methods for testing plugs and sockets, determining their conformity, and establishing general technical standards. These “General Requirements” are generally not considered superior or inferior to other standards; they are all mandatory. The series of plugs and sockets under the IEC 60320 standard (commonly referred to as IEC 320) is currently the most widely used and universal standard in the world for products such as computers and communication equipment. It is also a widely used type of plug and socket in China (GB 17465). Commonly used socket specifications include: IEC320C13 (10A) and IEC320C19 (16A); commonly used plug specifications include: IEC320C14 (10A) and IEC320C20 (16A). The most critical and prominent features of IEC320 standard plugs and sockets are: international standardization, strong universality, safe and reliable structure, and easy replacement .