IEC 61554:2025

IEC 61554 ®
Edition 2.0 2025-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Panel mounted equipment – Electrical measuring instruments – Dimensions for
panel mounting
Appareils montés en tableaux – Instruments de mesure électriques –
Dimensions pour le montage en tableaux

ICS 17.220.20  ISBN 978-2-8327-0381-6

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– 2 – IEC 61554:2025 © IEC 2025
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Requirements . 6
4.1 General . 6
4.2 Instrument size designation . 6
4.3 Dimensions of the cut-out . 6
4.4 Individual cut-out mounting . 6
4.5 Common cut-out mounting . 7
Annex A (normative) Dimensions for instruments with round housing . 11
A.1 General . 11
A.2 Overview. 11
A.3 Requirements . 11
A.3.1 General . 11
A.3.2 Instrument size designation . 11
A.3.3 Individual cut-out mounting . 11

Figure 1 – Square housing . 7
Figure 2 – Rectangular lateral housing . 7
Figure 3 – Rectangular upright housing . 8
Figure 4 – Common cut-out mounting . 8
Figure A.1 – Round housing with a square bezel. 12
Figure A.2 – Round housing with a rectangular bezel type 1 . 13
Figure A.3 – Round housing with a rectangular bezel type 2 . 15

Table 1 – Sizes and tolerances . 9
Table A.1 – Sizes and tolerances of round housing with a square bezel . 12
Table A.2 – Sizes and tolerances of round housing with a rectangular bezel type 1 . 14
Table A.3 – Sizes and tolerances of round housing with a rectangular bezel type 2 . 15

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PANEL MOUNTED EQUIPMENT –
ELECTRICAL MEASURING INSTRUMENTS –
DIMENSIONS FOR PANEL MOUNTING
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
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shall not be held responsible for identifying any or all such patent rights.
IEC 61554 has been prepared by IEC technical committee 85: Measuring equipment for
electrical and electromagnetic quantities. It is an International Standard.
This second edition cancels and replaces the first edition published in 1999. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Add more sizes and tolerances of instruments and some practical information for panel
mounting which were not mentioned in IEC 61554:1999;
b) Modify several current sizes and tolerance of instruments;
c) Update the figures in Annex A;
d) Change Annex A from informative to normative.

– 4 – IEC 61554:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
85/949/FDIS 85/956/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
PANEL MOUNTED EQUIPMENT –
ELECTRICAL MEASURING INSTRUMENTS –
DIMENSIONS FOR PANEL MOUNTING
1 Scope
This document defines a system of dimensions for panel mounting of equipment. It is applicable
to electrical and electrically operated indicating, recording and control instruments.
It applies to the following types of instruments with protruding bezels:
• instruments with square housing;
• instruments with rectangular housing with lateral orientation;
• instruments with rectangular housing with upright orientation;
• instruments with round housing and square bezel;
• instruments with round housing and rectangular bezel.
The purpose of this document is to establish dimensional interchangeability between
instruments made by different manufacturers. To fulfil this requirement, a defined set of
dimensions has been chosen. Using these dimensions, it will be easier to combine instruments
of different sizes on the same panel making good use of the available panel space and to
produce a satisfactory layout.
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.
ISO 2768-1, General tolerances – Part 1: Tolerances for linear and angular dimensions without
individual tolerance indications
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:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
cut-out
hole in the panel into which the instrument or group of instruments is inserted
3.2
bezel
front projecting surface or rim around the housing of the instrument

– 6 – IEC 61554:2025 © IEC 2025
3.3
instrument size
overall maximum width and height of the bezel
4 Requirements
4.1 General
The instrument size serves as a basis for defining the various dimensions which permit
interchangeability of the instrument.
Only positive tolerances are allowed for cut-out dimensions and only negative tolerances for
the instrument size.
The dimensions of the housings of the instruments are not specified in this document. The only
exception to this is instruments with round housing which shall be covered in Annex A.
Instruments that are mounted together in a common cut-out are shown as mounted without any
gaps between them. The method for determining the dimensions of the common cut-out is
specified below.
In Figure 1 to Figure 4 and Table 1 , the following symbols are used:
A1 bezel width;
A2 bezel height;
L1 cut-out width;
L2 cut-out height.
4.2 Instrument size designation
The size designation of instruments complying with the requirements of this standard shall be
as follows:
IEC 61554 – A1 × A2
4.3 Dimensions of the cut-out
In general, the dimensions of the cut-out shall allow easy central mounting of the instrument
into that cut-out.
On each side, the housing of the instrument shall have a clearance of at least 0,2 mm against
the cut-out of 48 mm or at least 0,5 mm for all other instruments. The maximum value of this
clearance shall be such that it shall still allow the instrument to find a position where the cut out
is not visible.
4.4 Individual cut-out mounting
The nominal instrument sizes and the corresponding cut-out sizes and maximum tolerances for
the different shapes of instruments shown in Figure 1, Figure 2 and Figure 3 are given in
Table 1.
The series of nominal instrument sizes and cut-out sizes can be extended according to the
logical sequence of values. Values for the corresponding upper tolerances shall be in
accordance with the relevant tolerance range specified in ISO 2768-1.

4.5 Common cut-out mounting
Instruments with square and rectangular housing are often mounted closely together in a group
in a common cut-out. In such instances the dimensions of the cut-outs depend upon the number
and sizes of the instruments and upon the overhang of the bezels of the instruments at either
end of the group.
When mounting a group of instruments in a row in a common cut-out, as shown in Figure 4, the
overall cut-out width L shall be calculated as the sum of the widths A1 of the individual
c
instruments in the group, minus 3 mm. Refer to the formula below:
n
LA13−
c ∑
This formula does not apply to instruments with a width A1 that is less than 36 mm.
The tolerance for a common cut-out width is the same as the tolerance for the smallest
instrument to be mounted in the common cut-out.
The same principles shall be used for calculating the cut-out size when mounting a group of
instruments in a single column in a common cut-out.
NOTE Instruments to be mounted in rows or columns can have fixing points on all four sides of the housing.
Dimensions in millimetres
Figure 1 – Square housing
Dimensions in millimetres
Figure 2 – Rectangular lateral housing
=
– 8 – IEC 61554:2025 © IEC 2025
Dimensions in millimetres
Figure 3 – Rectangular upright housing
Dimensions in millimetres
Figure 4 – Common cut-out mounting

Table 1 – Sizes and tolerances
Dimensions in millimetres
a
Instrument size
Cut-out size
Shape Series
A1 max A2 max L1 Upper tolerance L2 Upper tolerance
36 36 33 +0,6 33 +0,6
48 48 45 +0,6 45 +0,6
72 72 68 +0,7 68 +0,7
Series 12 96 96 92 +0,8 92 +0,8
144 144 138 +1,0 138 +1,0
192 192 186 +1,1 186 +1,1
288 288 282 +1,3 282 +1,3
Square 40 40 36 +0,6 36 +0,6
60 60 56 +0,6 56 +0,6
80 80 76 +0,7 76 +0,7
100 100 96 +0,7 96 +0,7
Series 10
110 110 104 +0,8 104 +0,8
120 120 113 +0,8 113 +0,8
160 160 152 +1,0 152 +1,0
240 240 227 +1,1 227 +1,1
48 24 45 +0,6 22,2 +0,3
72 36 68 +0,7 33 +0,6
96 24 92 +0,8 22,2 +0,3
96 48 92 +0,8 45 +0,6
Rectangular lateral Series 12 144 36 138 +1,0 33 +0,6
144 72 138 +1,0 68 +0,7
144 96 138 +1,0 92 +0,8
192 96 186 +1,1 92 +0,8
192 144 186 +1,1 138 +1,0
– 10 – IEC 61554:2025 © IEC 2025

a
Instrument size
Cut-out size
Shape Series
A1 max A2 max L1 Upper tolerance L2 Upper tolerance
70 40 67 +0,7 37 +0,6
80 40 76 +0,7 36 +0,6
Rectangular lateral Series 10 120 60 116 +0,8 56 +0,7
160 80 152 +1,0 76 +0,7
240 120 227 +1,1 116 +0,8
24 48 22,2 +0,3 45 +0,6
24 96 22,2 +0,3 92 +0,8
36 72 33 +0,6 68 +0,7
36 144 33 +0,6 138 +1,0
48 96 45 +0,6 92 +0,8
Series 12
72 144 68 +0,7 138 +1,0
96 192 92 +0,8 186 +1,1
Rectangular upright
96 144 92 +0,8 138 +1,0
144 192 138 +1,0 186 +1,1
192 288 186 +1,1 282 +1,3
40 80 36 +0,6 76 +0,7
60 120 56 +0,7 116 +0,8
Series 10
80 160 76 +0,7 152 +1,0
120 240 116 +0,8 227 +1,1
a
Lower tolerance = 0
Annex A
(normative)
Dimensions for instruments with round housing
A.1 General
Instruments that have a cylindrical or round housing are still in use in some parts of the world.
In recognition of this fact, this annex is intended to extend the requirements of this document
to cover such instruments.
A.2 Overview
This annex specifies the dimensions for a range of electrical and electrically operated
measuring instruments with round housings. It applies to indicating and recording instruments.
It applies to the following types of instruments with protruding bezels:
• instruments with round housing and square bezels;
• instruments with round housing and rectangular bezels.
A.3 Requirements
A.3.1 General
For instruments with round housing the diameter of the housing shall be specified.
The following symbols are used in this annex:
A1 bezel width
A2 bezel height
B1 lateral centre distance of fastening bolt hole
B2 upright centre distance of fastening bolt hole
D diameter of instrument housing
D1 diameter of cut-out
A.3.2 Instrument size designation
The size designation of instruments complying with the requirements of this document shall be
as follows:
IEC 61554 – A1 × A2 × D
A.3.3 Individual cut-out mounting
The nominal instrument sizes and the corresponding cut-out sizes and maximum tolerances for
the different shapes of instruments shown in Figure A.1, Figure A.2 and Figure A.3 are given in
Table A.1, Table A.2 and Table A.3.
When four bolts are used to fix the instrument, the positions of the four bolt holes are as shown
in Figure A.1 to Figure A.3. When two bolts are used, the positions of two bolt holes are at
bottom left and bottom right or diagonal locations when viewed from the front of the instrument
panel.
– 12 – IEC 61554:2025 © IEC 2025

Figure A.1 – Round housing with a square bezel
Table A.1 – Sizes and tolerances of round housing with a square bezel
Dimensions in millimetres
a
Instrument sizes Centre distance of fastening bolt hole
Cut-out sizes
Shape Series
Upper Limit Limit
D
B1 B2
max
tolerance tolerance tolerance
36 36 32 33 +0,6 28 ±0,2 28 ±0,2
48 48 44 45 +0,6 38 ±0,3 38 ±0,3
72 72 66 68 +0,7 58 ±0,3 58 ±0,3
Series
96 96 90 92 +0,8 78 ±0,3 78 ±0,3
144 144 136 138 +1,0 116 ±0,4 116 ±0,4
192 192 184 186 +1,1 156 ±0,5 156 ±0,5
40 40 35 36 +0,6 32 ±0,3 32 ±0,3
60 60 55 56 +0,7 48 ±0,3 48 ±0,3
80 80 65 67 +1,0 64 ±1,0 64 ±1,0
80 80 75 76 +0,7 64 ±0,3 64 ±0,3
100 100 85 87 +1,0 80 ±1,0 80 ±1,0
100 100 95 96 +0,7 80 ±0,3 80 ±0,3
110 110 99 102 +1,0 90 ±1,0 90 ±1,0
Square
Series
110 110 104 106 +0,8 90 ±0,4 90 ±0,4
120 120 109 112 +1,0 100 ±1,0 100 ±1,0
120 120 114 116 +0,8 96 ±0,4 96 ±0,4
150 150 109 112 +1,0 100 ±1,0 100 ±1,0
160 160 150 152 +1,0 128 ±0,5 128 ±0,5
240 240 225 227 +1,1 192 ±0,5 192 ±0,5
250 250 135 140 +1,0 180 ±1,0 180 ±1,0
300 300 135 140 +2.0 200 ±1.0 200 ±1,0
80 80 70 73 - 64 - 64 -
82 82 65.5 67 - 64 - 64 -
Others 110 110 100 104 - 90 - 90 -
102 102 85 88 - 80 - 80 -
122 122 110 113 - 100 - 100 -
a
* Lower tolerance = 0
Figure A.2 – Round housing with a rectangular bezel type 1

– 14 – IEC 61554:2025 © IEC 2025
Table A.2 – Sizes and tolerances of round housing with a rectangular bezel type 1
Dimensions in millimetres
a
Instrument sizes Centre distance of fastening bolt hole
Cut-out sizes
Shape Series
Upper Limit Limit
D
B1 B2
max
tolerance tolerance tolerance
64 56 52 53 +0,6 52 ±0,3 - -
64 56 59 60 +0,7 52 ±0,3 25 ±0,3
64 60 53 55 +0,5 48 ±0,5 48 ±0,5
Series
72 60 55 56 +0,7 54 ±0,3 46
...