EN 60917-2-2:1996

SLOVENSKI STANDARD
01-september-2002
Modular order for the development of mechanical structures for electronic
equipment practices - Part 2: Sectional specification - Interface co-ordination
dimensions for the 25 mm equipment practice - Section 2: Detail specification -
Dimensions for subracks, chassis, backplanes, front panels and plug-in units (IEC
60917-2-2:1994)
Modular order for the development of mechanical structures for electronic equipment
practices -- Part 2: Sectional specification - Interface co-ordination dimensions for the 25
mm equipment practice -- Section 2: Detail specification - Dimensions for subracks,
chassis, backplanes, front panels and plug-in units
Modulordnung für die Entwicklung von Bauweisen für elektronische Einrichtungen -- Teil
2: Strukturnorm - Schnittstellen-Koordinationsmaße für die 25-mm-Bauweise --
Hauptabschnitt 2: Maßnorm - Maße für Baugruppenträger, Einschübe, Rückplatten,
Frontplatten und steckbare Baugruppen
Ordre modulaire pour le développement des structures mécaniques pour les
infrastructures électroniques -- Partie 2: Spécification intermédiaire - Dimensions de
coordination pour les interfaces des infrastructures au pas de 25 mm -- Section 2:
Spécification particulière - Dimensions pour bacs, châssis, fonds de paniers, faces avant
et unités enfichables
Ta slovenski standard je istoveten z: EN 60917-2-2:1996
ICS:
31.240 Mehanske konstrukcije za Mechanical structures for
elektronsko opremo electronic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
IEC
INTERNATIONALE
917-2-2
INTERNATIONAL
Première édition
STANDARD
First edition
1994-04
développement
Ordre modulaire pour le
pour
des structures mécaniques
électroniques –
les infrastructures
Partie 2:
Spécification intermédiaire –
interfaces
de coordination pour les
Dimensions
–
des infrastructures au pas de 25 mm
Spécification particulière –
Section 2:
panier,
bacs, châssis, fonds de
Dimensions pour
unités enfichables
faces avant et
Modular order for the development
of mechanical structures for electronic
equipment practices –
Part 2:
Sectional specification –
co-ordination dimensions for
Interface
the 25 mm equipment practice –
2: Detail specification –
Section
for subracks, chassis, backplanes,
Dimensions
front panels and plug-in units
Copyright — all rights reserved
Droits de reproduction réservés —
© CEI 1994
rt of this publication may be reproduced or utilized in
Aucune partie de cette publication ne peut litre reproduite ni No pa
any form or by any means, electronic or mechanical,
utilisée sous quelque forme que ce soit et par aucun pro-
including photocopying and microfilm, without permission
cédé, électronique ou mécanique, y compris la photocopie et
in writing from the publisher.
les microfilms, sans l'accord écrit de l'éditeur.
Genève, Suisse
Bureau Central de la Commission Electrotechnique Internationale 3, rue de Varembé
"
Commission Electrotechnique Internationale CODE PRIX
International Electrotechnical Commission PRICE CODE v
Memauynaponnan 3nettrpoTexHnvecnaa KoML+ccIR
IEC
Pour prix, voir catalogue en vigueur
• •
For price, see current catalogue

–3–
917-2-2 © IEC:1994
CONTENTS
Page
FOREWORD 7
Clause
1 Scope
Normative references 2
3 Terminology
4 Equipment arrangement
5 Dimensions
5.1 Subracks
15 Type A subrack, connector application with backplane
5.1.1
27 5.1.2 Type B subrack, connector application without backplane
5.1.3 Type C subrack
5.1.4 Chassis 29
5.2 Backplane
Backplane dimensions 5.2.1
33 5.3 Internal co-ordination and backplane grid
5.4 Front panels on cabinets or racks and dimensions for subracks and chassis
mounting flanges
5.5 Types of plug-in units 39
41 5.5.1 P type plug-in units
47 P type plug-in units with injector/extractor handles
5.5.2
5.5.3 K frame type plug-in units to accommodate P type plug-in units
5.5.4 L frame type plug-in units with front panels to accommodate
51 P type plug-in units without front panels
53 5.5.5 M box type plug-in units with male guides
N box type plug-in units without male guides 5.5.6
Clearance of plug-in units in subrack 5.5.7
5.6 Terms, definitions and tables of dimensions
5.6.1 Nomenclature 59
63 5.6.2 Height dimensions
5.6.3 Width dimensions
5.6.4 Depth dimensions
Figures
Examples of subracks, backplanes, plug-in units and cabinet
or rack front panels
17 Dimensional relationship for subrack and plug-in units
3a Subrack dimensions for mounting plug-in units, plug-in unit guides
and backplanes 19
21 3b Dimensions of subracks and fastening arrangement

IEC:1994 - 5 -
917-2-2 ©
Pages
Figures
23 3c Plug-in unit guides and plug-in unit positions
Optional subrack with front panels for electromagnetic interference (EMI) shielding 4
27 Mounting dimensions for connectors without backplane
Type C subrack dimensions 29
7 Backplane dimensions
33 Relationship between reference planes and backplane grid
35 Mounting dimensions for rack or cabinet front panels, subracks and chassis
10 Mounting height dimensions for rack or cabinet front panels, chassis
37 and subrack mounting flanges
Examples of types of plug-in units 39
41 12 P type plug-in unit dimensions
Front panels for plug-in units 13
14 Printed board dimensions
47 P type plug-in unit injector/extractor handle dimensions
16 K frame type plug-in units 49
17 L frame type plug-in units
18 M box type plug-in units
19 N box type plug-in units
57 20 Typical plug-in unit arrangements

917-2-2 © - 7 -
IEC:1994
INTERNATIONAL ELECTROTECHNICAL COMMISSION
MODULAR ORDER FOR THE DEVELOPMENT
OF MECHANICAL STRUCTURES
FOR ELECTRONIC EQUIPMENT PRACTICES –
Part 2: Sectional specification – Interface co-ordination dimensions
for the 25 mm equipment practice –
Section 2: Detail specification – Dimensions for subracks, chassis,
backplanes, front panels and plug-in units
FOREWORD
The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
1)
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
Their preparation is entrusted to technical committees; any IEC National Committee interested in
the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. The IEC
collaborates closely with the International Organization for Standardization (ISO) in accordance with
conditions determined by agreement between the two organizations.
The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on
2)
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
They have the form of recommendations for international use published in the form of standards, technical
3)
reports or guides and they are accepted by the National Committees in that sense.
In order to promote international unification, IEC National Committees undertake to apply IEC International
4)
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
International Standard IEC 917-2-2 has been prepared by subcommittee 48D: Mechanical
structures for electronic equipment, of IEC technical committee 48: Electromechanical
components and mechanical structures for electronic equipment.
The text of this standard is based on the following documents:
Report on voting
DIS
48D(CO)32 48D(CO)35
rt
Full information on the voting for the approval of this standard can be found in the repo
on voting indicated in the above table.

917-2-2 ©
IEC:1994 - 9 -
MODULAR ORDER FOR THE DEVELOPMENT
OF MECHANICAL STRUCTURES
FOR ELECTRONIC EQUIPMENT PRACTICES –
Part 2: Sectional specification – Interface co-ordination dimensions
for the 25 mm equipment practice -
Section 2: Detail specification – Dimensions for subracks, chassis,
backplanes, front panels and plug-in units
1 Scope
This section of IEC 917-2 is a detail specification which is to be used in whole or in part in
all fields of electronics where devices and systems are designed according to the
sectional specification IEC 917-2.
The purpose of this publication is the specification of dimensions which will ensure
mechanical interchangeability of subracks, chassis, plug-in units, backplanes and front
panels.
The sectional specification IEC 917-2 has embodied within it a number of subrack systems
based on 25 mm three-dimensional modularity and the binary additive principle for
subrack heights.
The dimensions in the tables of this detail specification are based on one of the subrack
systems taken from the sectional specification IEC 917-2. However, all subrack systems
within the sectional specification are valid in this detail specification, provided the relation-
ship between the dimensions is maintained, i.e. the dimensional difference between the
S0 ,
co-ordination dimensions HS, W and DS and dimensions H S0 , etc.; W etc., and Dso,
etc., shown in tables 1, 2 and 3 are to be maintained.
The subrack dimensions are related to certain cabinet/rack dimensions, see IEC 917-2-1.
The front panel dimensions are related to the mounting dimensions of certain cabinets and
racks, see IEC 917-2-1.
Plug-in units are mounted in subracks. They serve as supports for electrical, electronic
and mechanical components. The electrical connection between plug-in units and
subracks is based on the use of connectors.
All dimensions are given in millimetres and the drawings are first angle projections.

917-2-2 ©IEC:1994 -11 -
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this section of IEC 917-2. At the time of publication, the
editions indicated were valid. All normative documents are subject to revision and parties
to agreements based on this section of IEC 917-2 are encouraged to investigate the possi-
bility of applying the most recent editions of the normative documents indicated below.
Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 249-2, rt 2: Specifications
Base materials for printed circuits - Pa
IEC 916: 1988, Mechanical structures for electronic equipment - Terminology
IEC 917: 1988, Modular order for the development of mechanical structures for electronic
equipment practices
Amendment 1: 1993.
IEC 917-0: 1989, Modular order for the development of mechanical structures for
electronic equipment practices - Pa 0: Guide for the users of IEC Publication 917
rt
IEC 917-2: 1992, Modular order for the development of mechanical structures for
electronic equipment practices - Pa rt 2: Sectional specification - Interface co-ordination
dimensions for the 25 mm equipment practice
IEC 917-2-1: 1993, Modular order for the development of mechanical structures for
electronic equipment practices - Part 2: Sectional specification - Interface co-ordination
dimensions for the 25 mm equipment practice - Section 1: Detail specification - Dimen-
sions for cabinets and racks
(in preparation)
IEC 1076, Connector standards related to this 25 mm equipment practice
3 Terminology
For the purposes of this section of IEC 917-2, the following terminology applies.
3.1 aperture dimensions: Dimensions used to define space between structural pa rts.
3.2 Reference dimension used to co-ordinate mechanical
co-ordination dimension:
interfaces, see IEC 917.
3.3 mounting pitch: Pitch used to arrange pa rts or assemblies in a given space.
3.3.1 mounting pitch for cabinets/racks and subracks: mp1 = 25 mm
3.3.2 mounting pitch for subracks and plug-in units mp2 = 5 mm
3.3.3 mounting pitch for subracks and plug-in units: mp3 = 2,5 mm

–13 –
917-2-2 ©IEC:1994
mp4 =0,5 mm
3.3.4 grid for backplane:
Two-dimensional or three-dimensional arrangement of pitch used to co-
grid:
3.4
ordinate position; see also IEC 917, 6.1, modular grid.
3.5 n: Integer.
Theoretical plane without thickness or tolerance, used to define
3.6 reference plane:
spaces. See IEC 917 and IEC 917-0.
4 Equipment arrangement
Fixed connector
Subrack
mounting
flange
L_
Plug-in unit
front panel
Plug-in unit
Plug-in unit into
with printed
a frame/box type
board
plug-in unit
Cabinet/rack
front panel
4$,
IEC 232/94
Figure 1 – Examples of subracks, backplanes, plug-in units and cabinet
or rack front panels
917-2-2 ©
IEC:1994 - 15 -
5 Dimensions
The subrack, chassis, backplane, front panel and plug-in unit dimensions for height, width
and depth have been taken from the relevant tables in IEC 917-2 (see 5.1.1.1). The
subracks, chassis, plug-in units, backplanes and front panels do not need to conform with
the figures illustrated; only the specified dimensions have to be applied. In the case of
unspecified dimensions and tolerances the manufacturer is free to choose according to his
requirements.
5.1 Subracks
The detail specification standardizes three types of subracks with interchangeability of all
types of plug-in units as shown in figure 1.
5.1.1 Type A subrack, connector application with backplane
Subracks designed according to type A shall be used for connector applications with a
subrack mounted backplane.
5.1.1.1 If other co-ordination dimensions are used then
...