GB/T 24276-2017 English PDFUS$599.00 · In stock
Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 24276-2017: A method of temperature-rise verification of low-voltage switchgear and controlgear assemblies by calculation Status: Valid GB/T 24276: Historical versions
Basic dataStandard ID: GB/T 24276-2017 (GB/T24276-2017)Description (Translated English): A method of temperature-rise verification of low-voltage switchgear and controlgear assemblies by calculation Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: K31 Classification of International Standard: 29.130.20 Word Count Estimation: 30,336 Date of Issue: 2017-11-01 Date of Implementation: 2018-05-01 Older Standard (superseded by this standard): GB/T 24276-2009 Regulation (derived from): National Standard Announcement 2017 No. 29 Issuing agency(ies): General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China GB/T 24276-2017: A method of temperature-rise verification of low-voltage switchgear and controlgear assemblies by calculation---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. A method of temperature-rise verification of low-voltage switchgear and controlgear assemblies by calculation ICS 29.130.20 K31 National Standards of People's Republic of China Replacing GB/T 24276-2009 Through the calculation of low-voltage switchgear and equipment A method of controlling equipment temperature rise verification (IEC /T R60890.2014, IDT) Posted.2017-11-01 2018-05-01 implementation General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China China National Standardization Administration released Directory Foreword Ⅲ Introduction IV 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Conditions of use 1 Calculate 1 5.1 Necessary information 1 5.2 Calculation Step 2 5.2.1 General 2 5.2.2 Determination of effective heat dissipation area Ae 2 5.2.3 Determination of mid-point air temperature Δt0.5 within the shell 2 5.2.4 Determination of the top of the air temperature inside the shell Δt1.0 2 5.2.5 shell air temperature characteristic curve 3 Design Assessment 4 Appendix A (Informative) Example of calculation of air temperature inside the enclosure 14 A.1 Example 1 14 A.2 Example 2 16 Appendix B (informative) conductor operating current and power loss 21 References 25 Figure 1 Ae more than 1.25m2 temperature rise characteristic curve 3 Figure 2 shell Ae does not exceed 1.25m2 temperature rise characteristic curve 4 Figure 3 without vents, the effective heat dissipation area Ae > 1.25m2 housing case constant k 6 Figure 4 without the vent, the effective heat dissipation area Ae > 1.25m2 shell temperature distribution coefficient c7 Figure 5 Case constant k 8 of the enclosure with vent, effective dissipation area Ae > 1.25m 2 Figure 6 with a vent, the effective heat dissipation area Ae > 1.25m2 shell temperature distribution coefficient c 9 Figure 7 without the vent, the effective cooling area Ae ≤ 1.25m2 case shell constant k 10 Figure 8 without the vent, the effective cooling area Ae ≤ 1.25m2 shell temperature distribution coefficient c 11 Figure 9 Calculation of the air temperature inside the enclosure 12 Figure A.1 Example 1, Calculation of a housing without a vent and an internal horizontal baffle but with a bare side 14 Figure A.2 Example 1, a single shell calculation 15 Figure A.3 Example 2, Calculation of wall-mounted enclosure with vent 17 Figure A.4 Example 2, Half Shell Calculation 17 Figure A.5 Example 2, Calculation of wall-mounted enclosure with vent 19 Table 1 Calculation methods, applications, formulas and characteristics 4 Table 2 Symbols, units and names 5 Table 3 Surface coefficient according to mounting type b 5 Table 4 without the vent, the effective cooling area Ae > 1.25m2 shell factor d 5 Table 5 with a vent, the effective heat dissipation area Ae > 1.25m2 shell factor d5 Table B.1 allows the conductor temperature 70 ℃ (ambient air temperature within the enclosure .55 ℃) Single-core copper cable operating current and Power loss 21 Table B.2 allows the conductor temperature 70 ℃ when the cable reduction factor k1 23 Table B.3 Operating current and power loss of rectangular copper cross-section, horizontal operation and bare copper busbar arranged perpendicular to its largest face (Ambient temperature inside the enclosure 55 ° C, conductor temperature 70 ° C) 23 Table B.4 Different Air Temperature Coefficients in Enclosures and/or Conductor k4 24 ForewordThis standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 24276-2009 "part of the type test evaluation of low-voltage switchgear and control equipment (PTTA) temperature rise Extrapolation ", and GB/T 24276-2009 compared to the main technical changes are as follows. --- In the structure and technical content by GB/T 7251.1-2013 adjustment; --- Appendix B of the contents of the amendment and improvement. This standard uses the translation method identical with IEC /T R60890.2014 "calculated by the low voltage switchgear and control equipment temperature A method of verification. " This standard proposed by the China Electrical Equipment Industry Association. This standard by the National Low-voltage switchgear and control equipment Standardization Technical Committee (SAC/TC266) centralized. This standard was drafted unit. Tianjin Electric Institute of Science and Technology Co., Ltd., Tianjin days Electronic Distribution Co., Ltd., the State Power Distribution Equipment Quality Supervision and Inspection Center (Tianjin days Electronic Control Equipment Testing Co., Ltd.), Hunan Electric Institute of Science and Technology, Zhejiang Sanchen Electric Co., Ltd. Secretary, Barry Electric Co., Ltd., Shenzhen brilliant Electric Industrial Co., Ltd., Ningxia Li Cheng Electric Group Co., Ltd. The main drafters of this standard. Wang Chunwu, Zhang Lei, Duan Yi, Wang Peng, Xie Lin, Guo Wei, Zhu Wen Tang, Cai Zonguang, Niu Guangjun. This standard replaces the standards previously issued as. --- GB/T 24276-2009.IntroductionGB/T 7251.1 design verification provides for low voltage power switchgear and control equipment (referred to as complete sets of equipment) temperature rise verification. Temperature rise Can be verified by testing, in a specified environment can also be used a variety of methods to verify. The initial manufacturer is responsible for selecting the temperature rise verification method. If applicable, this standard can also be used to verify the temperature rise of similar products based on other standards, the factors and coefficients set in this standard from a large number into Set of equipment measurement data, and the method has been compared with the test results to verify. Through the calculation of low-voltage switchgear and equipment A method of controlling equipment temperature rise verification1 ScopeThis standard specifies the calculation of low-voltage switchgear and control equipment by a method of temperature rise verification. This method is suitable for enclosed units or unit units without forced ventilation separate cabinet unit, does not apply to GB/T 7251 related product standards clearly specify the temperature rise verification method. Note 1. The materials and wall thickness commonly used for the housing may have a certain effect on the steady-state temperature. However, the generalized approach used in this standard ensures its suitability For steel, aluminum, cast iron, insulation and similar materials made of shell. The recommended method is to determine the air temperature inside the enclosure. Note 2. The air temperature inside the enclosure is equal to the air temperature inside the enclosure due to the ambient air temperature outside the enclosure plus the power loss of the installed equipment. Unless otherwise specified, the ambient air temperature outside the plant is the air temperature at which the installation location is 35 ° C (average over 24h). in case The temperature of the ambient air outside the complete equipment installation exceeds 35 ° C. This higher temperature is considered as ambient air temperature.2 Normative referencesThe following documents for the application of this document is essential. For dated references, only the dated version applies to this article Pieces. For undated references, the latest edition (including all amendments) applies to this document. GB/T 7251.1-2013 Low-voltage switchgear and control equipment - Part 1. General (IEC 61439-1.2011, IDT)3 Terms and definitionsGB/T 7251.1-2013 Terms and definitions apply to this document.4 conditions of useThis calculation method applies if the following conditions are met. --- Can get all the internal components of the power loss data; --- Shell within the power loss is approximately uniform distribution; --- Installed equipment layout is not obstruct air circulation; --- Installation of equipment designed for DC or AC less than or equal to 60Hz, the total supply current does not exceed 3150A; --- The layout of conductors and adjacent structural components with loads in excess of.200A minimizes eddy current and hysteresis losses; --- With natural ventilation shell, the exhaust port cross-sectional area of at least 1.1 times the cross-sectional area of the inlet; --- Complete sets of equipment or within the cabinet unit has no more than 3 horizontal partition; --- Shell with external vents with compartments, the surface of each horizontal partition vents should be at least the compartment horizontal cross-sectional area Of the 50%.5 calculation5.1 Necessary information The following data is required to calculate the temperature rise of the air inside the enclosure. See Appendix A for an example of calculating the air temperature rise inside the enclosure. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 24276-2017_English be delivered?Answer: Upon your order, we will start to translate GB/T 24276-2017_English as soon as possible, and keep you informed of the progress. The lead time is typically 2 ~ 4 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB/T 24276-2017_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 24276-2017_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.Question 5: Should I purchase the latest version GB/T 24276-2017?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB/T 24276-2017 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically. |
