1.1 Product definition This specification contains the initial, start of life dimensional, mechanical and environmental performance requirements which a fully installed blown fibre protected, non-sealed closure for duct and microduct cable, must meet in order for it to be categorised as an EN standard product. These products are suitable for installation of and use with microduct fibre units, microduct optical fibre cables, microduct and protected microduct as defined within EN 60794-5. When the non-sealed closures are installed in subterranean environments it is mandatory to use sealed ABF connectors meeting EN 50411-2-8 in order to guarantee the expected network performance and reliability. 1.2 Operating environment The tests selected combined with the severities and duration are representative of an outside plant for subterranean and/or aerial environment defined by: - ETSI EN 300 019 series: Class 8.1: underground locations (without earthquake requirement); - EN 61753-1: Category S: subterranean environment; Category A: aerial environment. 1.3 Test severity The test severities are based on IP40 (see EN 60529). The test criteria for all mechanical and environmental tests cover visual appearance, and protected microduct retention of the closure. It is generally accepted practice that liquids will enter the closure through its body or connected ducts. 1.4 Reliability Whilst the anticipated service life expectancy of the product in this environment is a minimum of 20 years, compliance with this specification does not guarantee the reliability of the product. This should be predicted using a recognised reliability assessment programme. 1.5 Quality assurance Compliance with this specification does not guarantee the manufacturing consistency of the product. This should be maintained using a recognised quality assurance programme. 1.6 Allowed fibre and cable types This closure standard covers all IEC/EN standard optical fibre microducts, and protected microducts with their various fibre capacities, types and designs. This includes optical fibre cable standard EN 60794-5. This product specification has only considered protected microduct cables containing microducts of same outside diameters. There are other hybrid protected microduct cables with microducts of differing OD’s; it may be possible to use these hybrids, however the user must verify suitability in each case. 1.7 Allowed microduct connector types This closure standard covers all EN standard microduct connectors, including: straight, reducer/enlarger stem, reducer/enlarger, close down, liquid block, liquid block with barb end, and end stop connectors. This includes EN 50411-2-8. 1.8 Microduct storage constraints Microduct excess storage is not required in all air blown fibre closures. Some closure types do not have sufficient internal space to provide storage. The need for microduct storage is provided inside the closure when opened, typically to ensure that there is enough microduct to fulfil the following functions: • remove the coiled microduct attached to the ‘closedown’ connectors, to a remote location, close to blowing equipment, in the process uncoiling the microducts to aid blowing; • provide additional microduct if repeated cut backs for connectors are planned or likely to be fitted throughout the closure life. The minimum microduct storage bend radius is based on the outside diameter and material selection, typically based on 12 times the outside diameter (below 8 mm) and 20 times above. During fibre blowing the bend radius is typically 20 times the microduct diameter.