IEC 62610-6:2020 pdf download

IEC 62610-6:2020 pdf download.Mechanical structures for electrical and electronic equipment – Thermal management for cabinets in accordance with IEC 60297 and IEC 60917 series
1 Scope
This part of IEC 62610 which deals with thermal management for cabinets in accordance with IEC 60297 and IEC 60917 series, provides compatible measurement methods of recirculation ratio and bypass ratio which are indicators for defining quality of airflow in the forced air cooling that can be commonly applied to indoor cabinets for mounting subrack and/or chassis-based equipment. NOTE 1 Both recirculation and bypass represent leakage airflows, i.e. detrimental phenomena in terms of cooling efficiency; their measurement is obviously aimed at their mitigation. This document contains the following: a) the definition of recirculation and bypass flow rates in the cooling of the cabinet, b) the levels of the recirculation ratio RC, c) the definition of the formula for the recirculation ratio RC s of forced air cooling subrack and/or chassis-based equipment installed in the cabinet, d) the definition formula of recirculation ratio RC r and bypass rate BP r of the entire cabinet, e) the requirements of the measuring method of each temperature necessary for calculating the recirculation ratio RC s , RC r and bypass ratio BP r . NOTE 2 This document includes the definition of measuring bypass ratio, but excludes the definition of levels of bypass ratio. The drawings used are not intended to indicate product design. They are only for explanatory indications for defining forced air cooling airflows. The recirculation and bypass measurement methods dealt with in this document are assumed to be applied to a cabinet installed indoors. The cooling air inlet is at the front or the bottom of the cabinet and the heated air is exhausted to the rear or the top. These methods are also applicable to a cabinet that is installed outdoors and has a cooling device such as a heat exchanger or an air conditioner on the front or the back (see Annex C). The recirculation ratio of a subrack or a cabinet is defined for each individual subrack or chassis- based equipment mounted in the cabinet or for the entire cabinet. The bypass ratio of a cabinet is defined for the entire cabinet.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http://www.electropedia.org/ ISO Online browsing platform: available at http://www.iso.org/obp 3.1 recirculation flow rate f RC flow rate of the air that returns directly from the exhaust of the equipment to be cooled to the intake side of the equipment 3.2 bypass flow rate f BP flow rate of the air going through a cabinet without going through any of the equipment to be cooled 3.3 recirculation ratio of a subrack RC s ratio of the recirculation flow rate of a subrack or a chassis-based equipment to the flow rate of the equipment 3.4 recirculation ratio of a cabinet RC r ratio of the total recirculation flow rate of all of the subracks mounted in a cabinet to the total flow rate of all of the subracks mounted in a cabinet 3.5 bypass ratio of a cabinet BP r ratio of the bypass flow rate of a cabinet to the airflow rate of a cabinet 3.6 dummy thermal load DTL simulator that reproduces thermal fluid behaviour such as heat dissipation and flow rate generated by subrack and/or chassis-based equipment Note 1 to entry: Generally, a heater and a fan mounted in a chassis are used, and the amount of heat dissipation and the fan flow rate can be adjusted.