IEC 62610-6:2020 pdf free 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 lEC 62610 which deals with thermal management for cabinets in accordance withIEC 60297 and lEC 60917 series,provides compatible measurement methods of recirculationratio and bypass ratio which are indicators for defining quality of airflow in the forced air coolingthat can be commonly applied to indoor cabinets for mounting subrack and/or chassis-basedequipment.
NOTE 1 Both recirculation and bypass represent leakage airflows, i.e. detrimental phenomena in terms of coolingefficiency; 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, of forced air cooling subrack and/or chassis-based equipment installed in the cabinet,
d) the definition formula of recirculation ratio RC, and bypass rate BP, of the entire cabinet,e) the requirements of the measuring method of each temperature necessary for calculating the recirculation ratio RC, RC, and bypass ratio BP,.
NOTE 2 This document includes the definition of measuring bypass ratio, but excludes the definition of levels ofbypass ratio.
The drawings used are not intended to indicate product design.They are only for explanatoryindications for defining forced air cooling airflows.
The recirculation and bypass measurement methods dealt with in this document are assumedto be applied to a cabinet installed indoors.The cooling air inlet is at the front or the bottom ofthe cabinet and the heated air is exhausted to the rear or the top. These methods are alsoapplicable to a cabinet that is installed outdoors and has a cooling device such as a heatexchanger 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 cabinetis defined for the entire cabinet.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies.For undated ‘references，the latest edition of the referenced document (including anyamendments) applies.
IEC 60297-3-100,Mechanical structures for electronic equipment – Dimensions of mechanicalstructures of the 482,6 mm (19 in) series – Part 3-100:Basic dimensions of front panels,subracks,chassis, racks and cabinets
5.1Cooling airflow in a cabinet
Figure 1 schematically shows the airflow in the cabinet in which the subrack is mounted, witharrows by size and direction according to the flow balance. In the equipment cabinet, coolingair is supplied from the front,enters from the inlet of the subrack into the interior, cools theinterior of the subrack, exhausts from the subrack, and is exhausted from the rear of the cabinet.A part of the cabinet intake bypasses the subrack and is directly exhausted to the outside ofthe cabinet without passing through the subrack.A part of the subrack exhaust air is recirculated,returning to the subrack intake and not exhausting outside the cabinet./down/IEC/IEC-62610-6-2020.rar