EN 50411-3-1:2025

SLOVENSKI STANDARD
01-december-2025
Nadomešča:
SIST EN 50411-3-1:2012
SIST EN 50411-3-1:2012/AC:2013
Sistemi za upravljanje z optičnimi vlakni in zaščitna ohišja za optične
komunikacijske sisteme - Specifikacije izdelka - 3-1. del: Stenska ali na drog
nameščena omarica za spoje, za kategoriji C in A
Fibre management systems and protective housings to be used in optical fibre
communication systems - Product specifications - Part 3-1: Wall or pole mounted box for
splices, for category C and A
LWL-Spleißkassetten und -Muffen für die Anwendung in LWL-Kommunikationssystemen
- Produktnormen - Teil 3-1: Faser Management System, Wandspleißverteiler für die
Kategorien C und A
Systèmes de gestion des fibres et boîtiers de protection destinés à être utilisés dans les
systèmes de communication par fibres optiques - Spécifications de produits - Partie 3-1:
Boîte de montage mural ou sur poteau pour les épissures, pour les catégories C et A
Ta slovenski standard je istoveten z: EN 50411-3-1:2025
ICS:
33.180.20 Povezovalne naprave za Fibre optic interconnecting
optična vlakna devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 50411-3-1

NORME EUROPÉENNE
EUROPÄISCHE NORM October 2025
ICS 33.180.20 Supersedes EN 50411-3-1:2012; EN 50411-3-
1:2012/AC:2012
English Version
Fibre management systems and protective housings to be used
in optical fibre communication systems - Product specifications -
Part 3-1: Wall or pole mounted box for splices, for category C
and A
Systèmes de gestion des fibres et boîtiers de protection LWL-Spleißkassetten und -Muffen für die Anwendung in
destinés à être utilisés dans les systèmes de LWL-Kommunikationssystemen - Produktnormen - Teil 3-1:
communication par fibres optiques - Spécifications de Faser Management System, Wandspleißverteiler für die
produits - Partie 3-1: Boîte de montage mural ou sur poteau Kategorien C und A
pour les épissures, pour les catégories C et A
This European Standard was approved by CENELEC on 2025-09-01. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50411-3-1:2025 E
Contents Page
European foreword . 4
1 Scope . 6
1.1 Product definition . 6
1.2 Operating environment . 6
1.3 Reliability . 6
1.4 Quality assurance . 6
1.5 Allowed fibre and cable types . 6
2 Normative references . 7
3 Terms and definitions . 8
4 Abbreviations . 10
5 Description . 10
5.1 Functions and configurations . 10
5.2 Cable seals . 11
5.3 Cable anchoring . 12
5.4 Fibre management system . 12
5.5 Passive optical components . 12
5.6 Materials . 12
5.7 Marking and identification. 13
6 Variants . 13
7 Dimensional requirements . 16
8 Tests . 17
8.1 Sample size . 17
8.2 Test sample preparation. 17
8.2.1 Fibre type for test samples . 17
8.2.2 Sealing performance test samples for boxes . 17
8.2.3 Optical performance test samples for boxes . 17
8.2.4 Test sample configuration for track or spur boxes . 17
8.2.5 Test sample configuration for distribution boxes . 18
8.3 Test and measurement methods . 19
8.4 Test sequence . 19
8.5 Pass/fail criteria . 19
9 Test report . 20
10 Performance requirements . 20
10.1 Dimensional and marking requirements . 20
10.2 Sealing, optical and appearance acceptance criteria . 20
10.3 Mechanical sealing performance requirements . 22
10.4 Environmental sealing performance requirements . 24
10.5 Mechanical optical performance requirements . 25
10.6 Environmental optical performance requirements . 28
10.7 Material requirements . 29
Annex A (normative) Fibre details for the test samples . 30
Annex B (normative) Sample size requirements . 31
Annex C (informative) Families of FMS covered in this document . 33
Annex D (informative) Dimensions of FMS for multiple element and multiple ribbon . 35
Annex E (informative) Dimensions of S type FMS for Single Circuit, Single Element and Single
Ribbon . 36
Bibliography . 38
Figures
Figure 1 — Fibre management configurations in a track box . 11
Figure 2 — Dimensions of optical fibre splice boxes . 16
Figure 3 — Example configuration of track or spur box test sample . 18
Figure 4 — Example configuration of distribution box test sample . 18
Figure C.1 — Families of FMS covered in this document . 34
Figure D.1 — Outline dimensions of the M type FMS . 35
Figure E.1 — Outline dimensions of the S type FMS . 36
Tables
Table 1 — Optical fibre splice box, for category C and A - variants . 13
Table 2 — Box size selection . 14
Table 3 — Optical fibre splice box dimensions . 16
Table 4 — Sealing, optical and appearance acceptance criteria . 20
Table 5 — Mechanical sealing performance requirements . 22
Table 6 — Environmental sealing performance requirements . 24
Table 7 — Mechanical optical performance requirements . 25
Table 8 — Environmental optical performance requirements . 28
Table 9 — Material requirements . 29
Table A.1 — Fibre references for EN IEC 60793-2-50, sub-category B-652.D . 30
Table A.2 — Fibre references for EN IEC 60793-2-50, sub-category B-657.A1 . 30
Table B.1 — Minimum sample size requirements . 31
Table D.1 — M type FMS - Multiple element and multiple ribbon fibre . 35
Table E.1 — Outline dimensions of S type FMS . 37
Table E.2 — Maximum capacity S type FMS - SC, SE and SR . 37
European foreword
This document (EN 50411-3-1:2025) has been prepared by CLC/TC 86BXA “Fibre optic interconnect, passive
and connectorised components”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2026-10-31
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2026-10-31
conflicting with this document have to be
withdrawn
This document supersedes EN 50411-3-1:2012 and all of its amendments and corrigenda (if any).
— update of the product category in title to Fibre management systems and protective housings;
— update of the product type in title to wall or pole mounted box for splices;
— addition of the application for pole mounting;
— update of the environmental categories to C and A according to EN IEC 61753-1:2018 ed2;
— update of the definition according to EN IEC 61753-1:2018;
— update of the description similar to EN 50411-3-4;
— replacement of the seven tables with box sizes, number of trays and splice capacity with one table reducing
the number of sizes to seven;
— deletion of box sizes V and W;
— improvement of the description and figures for the example configurations of box test sample preparation;
— update of the test specifications similar to EN 50411-3-4, that are based on EN IEC 61753-1:2018;
— removal of the smoke emission test method that was applicable for cables only.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A complete
listing of these bodies can be found on the CENELEC website.
Fibre management systems and protective housings to be used in optical fibre communication
systems — Product specifications —
Part 3-1: Wall or pole mounted box for splices, for category C and A
Description Typical installation configuration Typical mounting options
Vertical wall (external or internal)
Track box (2 cables minimum)
Pole mounted (above ground)
Wall or pole mounted box Spur box (3 cables minimum)
Inside street furniture (cabinet or
Distribution box (6 cables minimum)
pedestals)
Typical fibre management configurations

Operating service environments
Applications:
EN IEC 61753-1, category C
Optical fibre cable networks. For indoor and/or for
EN IEC 61753-1, category A
external above ground applications
Fibre separation levels in Fibre Management System
Single circuit (1, 2 or 4 fibre splices per tray), Single ribbon (1 ribbon fibre splice per tray),
Single element (6, 8 or 12 fibre splices per tray), Multiple ribbon (12 ribbons fibre splices per tray)
Multiple element (144 fibre splices per tray)
Box sizes, splice capacities and dimensions
Maximum overall box
Fibre
dimensions
splice
Box size
capacity Height
Width Depth
max.
mm mm
mm
A 24 280 450 100
G 48 400 450 150
D 72 400 600 200
E 96 460 600 180
K 144 460 610 210
L 192 420 550 180
N 288 460 600 180
1 Scope
1.1 Product definition
This document contains the dimensional, optical, mechanical and environmental performance requirements of
a fully installed optical fibre wall or pole mounted box for up to 288 fibre splices, in order for it to be categorized
as a European standard product.
The typical configuration is splicing of incoming fibres to optional splitters, connecting on the other side to
outgoing fibres.
A box is a protective housing containing a fibre management system with splice trays of various fibre separation
levels. The box can contain one or more of the following:
— storage and routing for fibre and cable;
— uncut fibre cable storage;
— splice trays;
— passive optical devices (optical splitters or WDM).
A box can be installed on a vertical indoor or outdoor surface above ground level. If the box is required to be
relocatable with cables attached, the following additional tests are expected to be performed:
— cable bending;
— cable torsion.
This document specifies the number of splice trays and splice capacity for each fibre separation level. The
maximum capacity is 288 splices. For housings with a higher number of splices, EN 50411-4-1 (street cabinets)
can be used.
Boxes for fibre splice and patchcord connections are covered in EN 50411-3-4.
1.2 Operating environment
The tests selected, combined with the severity and duration, are representative of indoor and outside plant for
above ground environments defined by EN IEC 61753-1:
— category C: Controlled (indoor) environment;
— category A: Aerial (outdoor above ground) environment.
1.3 Reliability
Whilst the anticipated service life expectancy of the product in this environment is 20 years, compliance with
this document does not guarantee the reliability of the product. This is expected to be predicted using a
recognized reliability assessment programme.
1.4 Quality assurance
Compliance with this document does not guarantee the manufacturing consistency of the product. This is
expected to be maintained using a recognized quality assurance programme.
1.5 Allowed fibre and cable types
This box standard accommodates EN IEC 60793-2-50 single-mode fibres and EN IEC 60793-2-10 A1-OM2 to
A1-OM5 and A1-OM1 multimode fibres and all EN 60794 series optical fibre cables with various fibre capacities,
types and designs.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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.
EN 60529, Degrees of protection provided by enclosures (IP Code) (IEC 60529)
EN 60695-11-10, Fire hazard testing — Part 11-10: Test flames — 50 W horizontal and vertical flame test
methods (IEC 60695-11-10)
EN 60754-1, Test on gases evolved during combustion of materials from cables — Part 1: Determination of the
halogen acid gas content (IEC 60754-1)
EN IEC 60793-2-10, Optical fibres — Part 2-10: Product specifications — Sectional specification for category
A1 multimode fibres (IEC 60793-2-10)
EN IEC 60793-2-50, Optical fibres — Part 2-50: Product specifications — Sectional specification for class B
single-mode fibres (IEC 60793-2-50)
EN IEC 61300-2-1, Fibre optic interconnecting devices and passive components — Basic test and
measurement procedures — Part 2-1: Tests - Vibration (sinusoidal) (IEC 61300-2-1)
EN IEC 61300-2-4, Fibre optic interconnecting devices and passive components — Basic test and
measurement procedures — Part 2-4: Tests - Fibre or cable retention (IEC 61300-2-4)
EN IEC 61300-2-5, Fibre optic interconnecting devices and passive components — Basic test and
measurement procedures — Part 2-5: Tests — Torsion (IEC 61300-2-5)
EN 61300-2-9, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 2-9: Tests — Shock (IEC 61300-2-9)
EN 61300-2-12, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 2-12: Tests — Impact (IEC 61300-2-12)
EN 61300-2-22, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 2-22: Tests — Change of temperature (IEC 61300-2-22)
EN 61300-2-26, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 2-26: Tests — Salt mist (IEC 61300-2-26)
EN 61300-2-33, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 2-33: Tests — Assembly and disassembly of fibre optic mechanical splices, fibre
management systems and closures (IEC 61300-2-33)
EN 61300-2-34, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 2-34: Tests — Resistance to solvents and contaminating fluids of interconnecting
components and closures (IEC 61300-2-34)
EN 61300-2-37, Fibre optic interconnecting devices and passive components - Basic test and measurement
procedures — Part 2-37: Tests — Cable bending for fibre optic closures (IEC 61300-2-37)
EN 61300-3-1, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 3-1: Examinations and measurements — Visual examination (IEC 61300-3-1)
EN 61300-3-3, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 3-3: Examinations and measurements — Active monitoring of changes in attenuation and
return loss (IEC 61300-3-3)
EN 61300-3-28, Fibre optic interconnecting devices and passive components — Basic test and measurement
procedures — Part 3-28: Examinations and measurements — Transient loss (IEC 61300-3-28)
EN IEC 61756-1, Fibre optic interconnecting devices and passive components — Interface standard for fibre
management systems — Part 1: General and guidance (IEC 61756-1)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
active fibre
live fibre
fibre in an optical circuit or node that is carrying an optical signal
3.2
box
free breathing housing that is permanently fixed to a wall or pole
Note 1 to entry: A box is not specifically designed to allow cable movement (e.g. torsion, bending) at the cable ports
during operation.
3.3
cable element
grouping of fibres in the cable sheath
3.4
fan-out
passive optical component providing a transition between a single ribbon or single element into individual fibres
3.5
fibre management system
system to control, protect and store splices, connectors, passive optical components and fibres from incoming
to outgoing cables
Note 1 to entry: A fibre management system is intended for installation within a protective housing.
Note 2 to entry: A fibre management systems is often called an “organiser”.
3.6
free breathing housing
protective housing that allows a free exchange of air with the environment
Note 1 to entry: Limited water ingress and/or limited dust ingress is possible. Free breathing housings are not intended for
use in areas that are subject to flooding or water immersion. Free breathing housings are used in aerial environments for
the interconnection of cables.
Note 2 to entry: A free breathing housing is not designed to hold a varying overpressure or underpressure caused by
temperature changes or atmospheric pressure changes.
3.7
microduct
small, flexible lightweight tube with an outer diameter between 3 mm and 16 mm
3.8
multiple element
ME
physical fibre separation level consisting of more than one single element
Note 1 to entry: This separation level has fibres from multiple cable elements on one splice tray and is also called mass
storage. It is the lowest (worst) degree of physical circuit separation.
3.9
multiple ribbon
MR
multiple element consisting of multiple optical fibres (circuits) arranged in ribbons (fibres in parallel) which are
arranged e.g. in stacks
3.10
passive optical component
optical component or assembly which does not require any source of energy for its operation other than optical
input signals, or controls the dynamic or static characteristics of optical signals using a source of energy
Note 1 to entry: A passive optical component never generates an optical gain of signal power.
Note 2 to entry: Examples include optical attenuators and passive branching devices.
3.11
protective housing
indoor or outdoor housing utilised for the storage, distribution or protection of one or more cable joints or passive
or active telecom equipment
Note 1 to entry: Examples of protective housings include: boxes, cabinets, cases, optical distribution frame sub racks,
closures or pedestals. A closure can be either a “sealed closure” or a “free breathing closure”.
Note 2 to entry: A protective housing contains a fibre management system.
3.12
single circuit
SC
physical fibre separation level where the optical circuit consists of one fibre (single fibre), or more than one fibre,
providing all services for one subscriber
Note 1 to entry: This fibre separation level has the fibre(s) of only one customer on one splice tray. It is the highest (best)
degree of physical circuit separation. Single circuit minimizes the disturbance of the operated circuits when accessing any
adjacent circuit.
3.13
single element
SE
physical fibre separation level in the cable subassembly comprising one or more optical fibres inside a common
covering e.g. in a tube or inside one groove of a grooved cable (slotted core cable)
Note 1 to entry: A single element provides services to more than one subscriber.
Note 2 to entry: This fibre separation level has all fibres from a cable element (e.g. loose tube) on one splice tray. It is an
intermediate degree of physical circuit separation (between single circuit and multiple element).
3.14
single ribbon
SR
physical fibre separation level with all fibres grouped in one ribbon
Note 1 to entry: Depending on the fibres’ deployment, a single ribbon can contain all the fibres of one circuit (single circuit)
or the fibres of more than one circuit (single element).
3.15
splice tray
structure that organises and controls storage of fibre splices in an orderly manner, together with the associated
excess uncabled fibre length
Note 1 to entry: A splice tray is a part of the fibre management system.
3.16
transient loss
short term (milliseconds) reversible change of optical transmission characteristics arising from optical
discontinuity, physical defects and modifications of the attenuation (e.g. bend loss) normally caused by
mechanical stress
3.17
uncut fibre
fibres from a continuous cable with the cable sheath removed over a defined length
Note 1 to entry: Uncut fibres typically comprise a section of cable where the cable sheath has been removed and the cable
tubes or uncut fibres are cleaned as for installation. These uncut tubes or fibres are then stored, usually inside a protective
housing, in a loop. When required the fibres or tubes are then cut and the fibres connected or spliced.
4 Abbreviations
For the purposes of this document, the following abbreviations apply.
FMS Fibre Management System
FTTH Fibre to the Home
ME Multiple Element
MR Multiple Ribbon
NA Not applicable
SC Single Circuit
SE Single Element
SR Single Ribbon
WDM Wavelength Division Multiplexer
5 Description
5.1 Functions and configurations
An optical fibre box is a housing that is attached to a wall or pole and contains the ends of the terminated cables.
The design of the box shall allow the interconnection of cable ends or fibre units.
A box has a means of containing and protecting the fibres, splices, and other passive optical devices.
A box used for blown cabling contains an area where the ends of the micro-ducts or the protected micro-ducts,
which may be terminated with water and gas blocking, are placed.
The design of the box may allow the joining together of at least one pair of cables which are not at the end of a
cable section without cutting all fibres between both cable openings. This application is generally known as track
joint or external node, but also called a mid-span or balloon splice box. If more than or equal to three cables
enter the box it is called a spur box and if more than or equal to six cables enter the box it is called a distribution
box.
A box shall be able to be re-opened without interruption or disturbance of the traffic of the live circuits within the
box.
The main fibre management configurations of the optical fibre distribution boxes in this specification is given in
Figure 1.
Figure 1 — Fibre management configurations in a track box
5.2 Cable seals
For environmental category A the cable entry or exit ports in the box shall have a sealing and attachment system
that can be:
a) heat activated by a heat source, for example, electrical, infrared, hot air or flame:
— thermo-shrinkable materials;
— hot melt adhesives;
— polyethylene injection welding;
b) cold applied:
— mastic, tapes, pastes, potting compounds, gels and cold adhesives;
— o-rings, grommets, rubber shapes, pre-expanded tubing;
c) combination of heat activated and cold applied.
5.3 Cable anchoring
The outer cable sheath and central strength members shall be attached to the hardware of the box. The cable
anchoring shall not be disturbed when adding or removing cables. Small diameter drop cable, cords or
microducts are typically attached by mechanical clamping on the outer cable sheath. The design of the cable
clamps shall not cause any optical performance degradation of the cables.
5.4 Fibre management system
The FMS provides means to control, protect and store splices, connectors, passive optical components and
fibres from incoming to outgoing cables. The fibre management system in the box shall be compliant with the
requirements of EN IEC 61756-1.
Fibre circuits may be separated to an appropriate separation level SC, SE, SR, ME and MR. This will limit the
risk of interruption to traffic in those fibres belonging to the same group of circuits.
The minimum storage radius of fibres in an FMS depends on:
— required failure probability target (location in the network);
— length of fibre to be stored;
— fibre type;
— longest transmission wavelength;
— maximum allowed attenuation increase (macro bending loss).
NOTE 1 The families of FMS covered in this document are listed in Annex C.
NOTE 2 Definitions of fibre separation levels SC, SE, SR, ME, MR are listed in Clause 3.
NOTE 3 EN IEC 61756-1 provides recommended storage radii for single-mode and multimode fibres.
NOTE 4 Dimensions of FMS for multiple element and multiple ribbon are given in Annex D – Figure D.1 and Table D.1.
NOTE 5 Dimensions of S type FMS for single circuit, single element and single ribbon are given in Annex E – Figure E.1,
Table E.1 and Table E.2.
For fibre types other than EN IEC 60793-2-10 category A1 and EN IEC 60793-2-50 sub-category B-652.B, B-
652.D and sub-category B-657, the minimum storage radius shall be 30 mm.
5.5 Passive optical components
Passive optical components that may be installed inside an FMS splice tray, or in separately mounted modules
or cassettes. Typical passive optical devices include splitters, wavelength division multiplexers (WDM) and fan-
outs.
5.6 Materials
NOTE All materials that are likely to come in contact with personnel are expected to meet appropriate local health,
safety and environmental regulations.
All components of the box shall be resistant to solvents and degreasing agents that are typically used to clean
and degrease fibres and cables.
For category A boxes, the exposed polymeric materials shall be UV light and fungi resistant.
The performance of metallic parts shall not be affected by corrosive influences they could encounter during the
lifetime of the product.
All materials shall be halogen free for category C boxes as specified in Clause 10. These requirements are valid
for all the materials that the box is made of as well as all components that are installed in it (during assembly
and at a later time).
5.7 Marking and identification
Marking/identification of the ‘variant number’ (see Clause 6) shall be on the product or packaging label along
with the following:
a) identification of manufacturer;
b) manufacturing date code: year / month.
There is no preferred colour for the outer wall box material. If a specific colour is required it should be specified
to the supplier separately from the ‘variant number’.
6 Variants
Table 1 gives for each variant number the options with a brief description.
Table 1 — Optical fibre splice box, for category C and A - variants
EN 50411-3-1– X – XX – XX – [XX – XX ] X – X
1 2 3 4 5 – 6 7
Variant No.
Operating environment
X
C Controlled environment (indoor)
A Aerial environment (outdoor)
B Both indoor (controlled) and outdoor (above ground level) environments

Variant No.
FMS nominal fibre storage radius
XX
20 20 mm for bending loss insensitive fibres (FTTH only)
30 30 mm for all fibre types
Variant No.
Box application – number of cable
XX
T Track box (2 cables minimum)
S Spur box (3 cables minimum)
D1 Distribution box (6 cables minimum)
D2 Distribution box (10 cables minimum)
D3 Distribution box (18 cables minimum)
D4 Distribution box (34 cables minimum)
D5 Distribution box (66 cables minimum)
Variant No.
Type of fibre splice tray (fibre separation level)
XX
SC Single circuit (up to 4 single fibre splices)
SE Single element (up to 12 single fibre splices)
SR Single ribbon (1 ribbon fibre splice with 4 or more fibres per ribbon)
ME Multiple element (24 to 144 single fibre splices – 2 or more cable elements)
MR Multiple ribbon (2 to 12 ribbon fibre splices – 4 or more fibres per ribbon)

Number of splice trays
Variant No.
(The maximum number of splice trays depends on the size and capacity of the box as
XX
specified by variants X )
01 to 99 Number of splice trays

Variant No.
Cable element storage
X
Y Yes
N No
Depending on the required number of splices and the selection of XX and XX , refer to Table 2 to find X (box
4 5 7
size).
Table 2 — Box size selection
Number of splice trays, XX
Reference to sizes
Box
Number of
(one tray type XX only)
defined in
size,
fibre splices
EN 50411-3-1:2012
X
max.
a b c d e
(informative) SC SE SR ME
A A, F 24 12 2 - -
G G 48 24 4 - -
D B, C, D, H, P 72 36 6 6 -
E E, J, Q 96 48 8 8 -
K K, T 144 - 12 - 6
L L, R 192 - 16 16 -
N N, S 288 - 24 24 -
a
The letters listed are defined in EN 50411-3-1:2012 and are included for information purpose
only. The box sizes defined in this table enclose the sizes defined in EN 50411-3-1:2012 but the
overall maximum box dimensions and/or the maximum number of fibre splices can be larger as
specified previously. Type V and W are no longer included.
b
2 fibre splices per SC splice tray.
c
12 fibre splices per SE splice tray.
d
1 ribbon splice (with 12 fibres per ribbon) per splice tray.
e
24 fibre splices per ME splice tray. Less splice trays are allowed when splice capacity of the ME
splice tray is more than 24 fibre splices (for example 72 or 144 fibre splices per splice tray).
This product specification is concerned with only one type of fibre tray at a given fibre separation level in
parameter XX . If multiple fibre splice tray types in a single splice box are required, then typically double the
number of SC trays can be inserted in the same fibre tray envelope as an SE (see also Table E.1).
This results in the following calculation of the maximum splice capacity:
Maximum splice capacity ≥ 2 * (number of SC trays) + 12 * (number of SE trays)
Part number format:
EN 50411-3-1 – X – XX – XX – [XX – XX ] – X – X
1 2 3 4 5 6 7
Three typical examples as follows:
EN 50411-3-1 – C – 30 – T – [SC – 24] – N – G
Controlled indoor environment, 30 mm fibre storage radius, track box, 24 single circuit trays, no cable storage
requirement and box size G.
EN 50411-3-1 – B – 30 – S – [SC – 06] + [SE – 01] – N – A
Both indoor and outdoor environments, 30 mm fibre storage radius, spur box, 6 single circuit trays plus 1 single
element tray, no cable storage requirement and box size A.
EN 50411-3-1 – A – 20 – D3 – [SE – 24] – Y – N
Outdoor aerial environment, 20 mm fibre storage radius, distribution box with 18 cables minimum, 24 single
element trays, cable storage requirement and box size N.
7 Dimensional requirements
Figure 2 — Dimensions of optical fibre splice boxes
Figure 2 shows the outer box dimensions and Table 3 specifies the maximum overall dimensions per box size.
Cable ports are often located underneath the box, as illustrated in Figure 2 as an example. However,
applications exist where boxes with one or more cable ports located at any other side are required, e.g. at the
top side.
Table 3 — Optical fibre splice box dimensions
Maximum overall box dimensions
Fibre splice
Box size capacity Height
Width Depth
max.
mm mm
mm
A 24 280 450 100
G 48 400 450 150
D 72 400 600 200
E 96 460 600 180
K 144 460 610 210
L 192 420 550 180
N 288 460 600 180
8 Tests
8.1 Sample size
Separate test samples for sealing performance and optical evaluation may be used. For the purposes of this
document, a sealing performance test sample is defined as a box installed with several cable ends.
Optical test samples shall be constructed as described in 8.2. Due to their complexity, consecutive testing on
the same optical sample is allowed.
The minimum sample sizes shall be according to Annex B – Table B.1.
8.2 Test sample preparation
8.2.1 Fibre type for test samples
The fibres selected for the optical test samples depend on the product variant XX . The fibres for the optical
test samples with 30 mm fibre storage radius shall be according to Annex A - Table A.1. The fibres for the optical
test samples with 20 mm fibre storage radius shall be according to Annex A - Table A.2.
Once the box is qualified for single-mode it can be considered to be qualified for multimode fibre.
8.2.2 Sealing performance test samples for boxes
Sealing performance test samples shall be installed to maximum capacity with cables and/or microducts. The
length of the cables and microducts extending from the boxes shall be long enough to perform the tests (typically
1 m). The open ends of the cables and microducts shall be sealed. Cables with minimum and maximum
diameter as specified by the manufacturer shall be represented in the test program.
8.2.3 Optical performance test samples for boxes
Optical test samples for boxes shall be constructed in such a way that they will cover all allowed functions of a
box. This shall be achieved by building optical circuits for each fibre separation level (typically SC, SE, SR, ME
or MR splicing).
The length of the cables is chosen to be longer than the “dead zone” of an OTDR. Typically, a looped cable
length of 25 m to 50 m is used, allowing location of the potential causes of optical losses and to distinguish
whether a change in signal is induced by the fibre management system in a single location or is distributed
evenly over the whole circuit length where several fibre circuits are placed in series.
All relevant fibre separation levels (SC, SE, SR, ME and MR) shall be represented in the test sample, preferably
in separate circuits.
Non-active fibres of the cables will be installed in the box and the fibres will be stored randomly in the fibre
management system in between the uncut fibres. These fibres will be accessed again during the
intervention/reconfiguration test 13.
8.2.4 Test sample configuration for track or spur boxes
Both extremities of a looped cable are terminated in the track or spur box as shown in Figure 3.
In the track or spur box the fibres from one cable end are connected to the fibres of the other cable end in such
a way that light will sequentially flow through ten selected fibres in the cable loop per circuit. The first and the
last fibre of this circuit will be spliced to the fibres of a test cable for making external connections to an optical
measurement equipment. As a result, eleven fibre splices join the serially connected fibres for each circuit. In
Figure 3 three circuits are shown as an example for testing the three separation level SC, SE and ME.
Figure 3 — Example configuration of track or spur box test sample
For the mechanical tests, the track or spur box without the looped cable is the device under test (DUT), and for
the environmental tests, the track or spur box with the looped cable is the DUT and shall be included in the test
environment.
8.2.5 Test sample configuration for distribution boxes
Both ends of a looped cable are terminated in the track or spur box as shown in Figure 4. A track or spur box is
used because the different cable elements at both cable ends of the looped cable are fixed in the same way as
in a real installation. Using only fibre trays would not fix the different cable elements at the cable ends properly.

Figure 4 — Example configuration of distribution box test sample
In the middle of the looped cable, the cable jacket will be removed over a distance (window cut) according to
the installation instructions. The tube of uncut fibres will be inserted and stored inside the distribution box (see
Figure 4). The other ends of the looped test cable are spliced together and the first and last fibre spliced to a
test cable. As a result, eleven fibre splices join the serially connected fibres for each circuit (circuits 1, 2 and 3).
In Figure 4, four circuits are shown as an example for testing the separation levels SC, SE and ME as well as
the looped test drop cable. The fibres of the test cable are connected to the optical measurement equipment.
Both extremities of a looped drop cable are terminated in the distribution box as shown in Figure 4 (Circuit 4).
Two fibres of the looped drop cable shall be spliced to fibres of the looped test cable that is connected to the
track or spur box. These fibres shall be again spliced to fibres in the test cable and connected to the optical
measurement equipment.
Example of fibre way of circuit no. 1 with SC trays:
I1 – a – SC tray – c – A – 9x (B – b – SC tray – c – A) – B – b – SC tray – a - O1
Example of fibre way of circuit no. 2 with SE trays:

I2 – a – SE tray – c – A – 9x (B – b – SE tray – c – A) – B – b – SE tray – a – O2
Example of fibre way of circuit
...