Detail of GB 20943-2025

Introduction of GB 20943-2025

GB 20943-2025 Minimum allowable values of energy efficiency and energy efficiency grades for AC-DC and AC-AC power supplies 1 Scope This document specifies the energy efficiency grades and energy efficiency limits of power supplies (hereinafter referred to as products) that convert AC voltage to low-voltage DC (not more than 60V) or low-voltage AC (not more than 42.4V) output voltages under 220V and 50Hz power supply conditions, and describes the corresponding test methods. This document is applicable to: a) External power supply with rated output power not greater than 500W and internal power supply with rated output power not greater than 27.5kW for microcomputers and servers; b) Extension cord receptacles, wall receptacles, and power parts of converters for power adapters with universal serial bus (USB) ports. This document is not applicable to, except those specified in b), combined products with an external power supply as an auxiliary function, combined products with batteries (including products that charge independent batteries), external power supplies with wireless charging, external power supplies for power over ethernet (POE), and products that power industrial equipment, vehicles, and medical devices. 2 Normative references The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 external power supply adapter product that converts the AC grid voltage to DC or AC voltage and is connected to electrical products through wires, cables or other interfaces to provide one or more DC or AC output voltages when in use Note: The power supply can be used independently, not fixed on the electrical products, and completely separated from the electrical products. 3.2 single voltage output external power supply external power supply that provides only one DC or AC output voltage per use Note: The power supply with nominal output voltage less than 6V and nominal output current greater than or equal to 550mA is low-voltage single voltage output external power supply, or basic voltage single voltage output external power supply, except for low voltage. 3.3 adjustable voltage single voltage output external power supply external power supply is adjustable by means of single-port protocol and other methods, and provides only one DC or AC output voltage per use 3.4 multiple voltage output external power supply external power supply that connected to electrical products through multiple wires, cables or multiple output ports to provide more DC or AC output voltages when in use 3.5 internal power supply AC-DC power supply that connected to equipment or components that use its power supply through output connector, and jointly installed in the same equipment housing, with a relatively independent power supply form 3.6 active mode the mode of output current between zero (excluding) to rated current where the input end of product is connected to network source and output end is connected to load 3.7 no load mode the mode that the input end of product is connected to the network source and the output end is not connected to load or the load does not consume electric energy 3.8 active mode efficiency ratio of actual output power to actual input active power where the product reaches steady active mode 3.9 average efficiency average of active mode efficiency of product under the current intensity of 100%, 75%, 50% and 25% of the rated output current. 3.10 minimum allowable values of energy efficiency for external power supply the allowable minimum average efficiency, the maximum active power under no-load conditions and the minimum power factor in the rated state of product under the test conditions specified in this document 3.11 minimum allowable values of energy efficiency for internal power supply the allowable minimum active mode efficiency and the minimum power factor of product under the test conditions specified in this document 4 Technical requirements 4.1 Energy efficiency grade 4.1.1 Energy efficiency grade of external power supply Energy efficiency grades of external power supply are classified into 3 grades and energy efficiency Grade 1 therein is the highest. The minimum average efficiency at each level of active mode, maximum active power under no load mode, and minimum power factor under rated condition of the external power supply shall meet the requirements of Tables 1 to 4. Among them, for products with adjustable voltage single voltage output, two modes of minimum output voltage and maximum output voltage shall be tested. As the nominal value of output power shall meet the requirements of Table 3, the lower of the corresponding level of the two shall be selected to determine the energy efficiency grade of the product. The minimum average efficiency in the active mode, the maximum active power in the no load mode, and the minimum power factor in the rated state of the external power supply shall be rounded off to 3 decimal places in accordance with GB/T 8170.

Contents of GB 20943-2025

Contents Foreword 1 Scope 2 Normative references 3 Terms and definitions 4 Technical requirements 5 Test methods Annex A (Normative) Test methods of external power supply average efficiency, no-load active power and power factor Annex B (Normative) Methods of multiple voltage output external power supply load combination Annex C (Informative) Example description of multiple voltage output external power supply load combination Annex D (Normative) Test methods of embedded power supply efficiency and power factor