prEN IEC 60393-4:2022

Potentiometers for use in electronic equipment - Part 4: Sectional specification: Single-turn rotary power potentiometers - Methods and guidance

Potentiomètres utilisés dans les équipements électroniques - Partie 4: Spécification intermédiaire: Potentiomètres de puissance rotatifs, à un seul tour

Potenciometri za elektronsko opremo - 4. del: Področna specifikacija: enoobratni vrtljivi potenciometri moči - Metode in navodila

General Information

• Status: Not Published
• Publication Date: 30-Jun-2024
• ICS: 31.040.20 - Potentiometers, variable resistors
• Technical Committee: CLC/SR 40 - Capacitors and resistors for electronic equipment
• Drafting Committee: IEC/TC 40 - IEC_TC_40
• Current Stage: 4060 - Enquiry results established and sent to TC, SR, BTTF - Enquiry
• Start Date: 03-Mar-2023
• Completion Date: 03-Mar-2023
• Ref Project: oSIST prEN IEC 60393-4:2023 - Potentiometers for use in electronic equipment - Part 4: Sectional specification: Single-turn rotary power potentiometers - Methods and guidance

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN IEC 60393-4:2023
01-februar-2023
Potenciometri za elektronsko opremo - 4. del: Področna specifikacija: enoobratni
vrtljivi potenciometri moči - Metode in navodila

Potentiometers for use in electronic equipment - Part 4: Sectional specification: Single-

turn rotary power potentiometers - Methods and guidance

Potentiomètres utilisés dans les équipements électroniques - Partie 4: Spécification

intermédiaire: Potentiomètres de puissance rotatifs, à un seul tour
Ta slovenski standard je istoveten z: prEN IEC 60393-4:2022
ICS:
31.040.20 Potenciometri, spremenljivi Potentiometers, variable
upori resistors
oSIST prEN IEC 60393-4:2023 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 60393-4:2023
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oSIST prEN IEC 60393-4:2023
40/2988/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60393-4 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2022-12-09 2023-03-03
SUPERSEDES DOCUMENTS:
40/2919/CD, 40/2952/CC
IEC TC 40 : CAPACITORS AND RESISTORS FOR ELECTRONIC EQUIPMENT
SECRETARIAT: SECRETARY:
Netherlands Mr Ronald Drenthen
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
Other TC/SCs are requested to indicate their interest, if any, in
this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY

SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING

Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for Vote
(CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.

This document is still under study and subject to change. It should not be used for reference purposes.

Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.
TITLE:

Potentiometers for use in electronic equipment – Part 4: Sectional specification: Single-turn rotary power

potentiometers – Methods and guidance
PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:

Copyright © 2022 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this

electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.

You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without

permission in writing from IEC.
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oSIST prEN IEC 60393-4:2023
40/2988/CDV – 2 – IEC CDV 60393-4 © IEC 2022
CONTENTS

FOREWORD ........................................................................................................................... 4

1 Scope .............................................................................................................................. 6

2 Normative reference ........................................................................................................ 6

3 Terms and definitions ...................................................................................................... 7

3.1 Terms ..................................................................................................................... 7

3.1.1 Potentiometer / Rheostat ........................................................................................ 7

3.1.2 Total Resistance (Rt) .............................................................................................. 7

3.1.3 Minimum resistance ................................................................................................ 7

3.1.4 End resistance ........................................................................................................ 7

3.1.5 Category dissipation ............................................................................................... 7

3.1.6 Nominal temperature ............................................................................................... 7

3.1.7 Nominal dissipation (Pn) ......................................................................................... 8

4 Preferred characteristics .................................................................................................. 8

4.1 General ................................................................................................................... 8

4.2 Style and dimensions .............................................................................................. 8

4.2.1 Preferred styles and outline dimensions ........................................................... 8

4.3 Preferred climatic categories ................................................................................... 9

4.4 Resistance law ........................................................................................................ 9

4.5 Nominal total resistance .......................................................................................... 9

4.6 Tolerances on nominal total resistance ................................................................... 9

4.7 Rated dissipation .................................................................................................... 9

4.8 Limiting element voltage ....................................................................................... 10

4.9 Insulation voltage .................................................................................................. 10

4.10 Number of cycles of operation ............................................................................... 10

4.11 Spindle rotational speed........................................................................................ 10

5 Tests and test severities ................................................................................................ 11

5.2 Mounting………………………………………………………………………………............10

5.3 Tests..................................................................................................................... 11

5.3.1 Resistance……………………………………………………………………..……………..10
5.4 Drying……………………………………………………………………………………………10

5.5 Vibration ............................................................................................................... 11

5.6 Bump .................................................................................................................... 11

5.7 Shock ................................................................................................................... 11

5.7.1 Temperature coefficients and temperature characteristics of resistance ................ 12

6 Performance requirements ............................................................................................. 12

6.1 General ................................................................................................................. 12

6.2 Limits for change in resistance or output voltage ratio ........................................... 13

6.3 Limits for temperature rise .......................................................................... ………..12

6.4 Limits for insulation resistance .............................................................................. 13

6.5 Limits for resistance law ........................................................................................ 13

6.6 Limits for operating torque .................................................................................... 13

6.7 Limits for end stop torque ..................................................................................... 14

6.8 Limits for Residual Resistances ............................................................................ 14

6.9 Visual inspection ................................................................................................... 14

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6.9.1 General visual criteria .................................................................................... 14

6.9.2 Visual criteria after tests ................................................................................ 15

6.10 Solderability .......................................................................................................... 15

7 Marking, packaging and ordering information ................................................................. 15

7.1 Marking of the component ..................................................................................... 15

7.2 Marking for packaging ........................................................................................... 15

7.3 Additional marking ................................................................................................ 15

7.4 Style…………………………………………………………………………………...………..15

7.5 Ordering information ............................................................................................. 16

8 Detail specifications ....................................................................................................... 16

8.1 General ................................................................................................................. 16

8.2 Information to be specified in a detail specification ............................................... 16

8.2.1 Outline drawing or illustration ........................................................................ 16

8.2.2 Style and dimensions ..................................................................................... 16

8.2.3 Mounting ............................................................................................................... 16

8.2.4 Resistance law ...................................................................................................... 16

8.2.5 Ratings and characteristics ................................................................................... 16

8.2.6 General ......................................................................................................... 16

8.2.7 Nominal total resistance range ....................................................................... 17

8.2.8 Marking ................................................................................................................. 17

8.2.9 Ordering information ............................................................................................. 17

8.2.10 Additional information ........................................................................................... 17

9 Quality assessment procedures ..................................................................................... 17

9.1 General ................................................................................................................. 17

9.2 Definitions ............................................................................................................. 17

9.2.1 Primary stage of manufacture ........................................................................ 17

9.2.2 Structurally similar components ..................................................................... 17

9.3 Assessment level EZ ............................................................................................. 17

10 Qualification Approval .................................................................................................... 18

10.1 General ................................................................................................................. 18

10.2 Qualification Approval on the basis of the fixed sample size procedure

Sampling ............................................................................................................... 18

10.3 Tests..................................................................................................................... 18

11 Quality Conformance Inspection .................................................................................... 32

11.1 Formation of inspection lots .................................................................................. 32

11.2 Test schedule ....................................................................................................... 32

11.3 Assessment levels ................................................................................................ 32

11.4 Delayed delivery ................................................................................................... 35

12 Apparatus for measuring mechanical accuracy .............................................................. 35

12.1 Dial indicator ......................................................................................................... 35

12.2 Cylindrical spindle adaptor .................................................................................... 35

12.3 Potentiometer mounting fixture ............................................................................. 36

12.4 Potentiometer spindle holding fixture .................................................................... 36

Bibliography .......................................................................................................................... 37

Annex A (informative) Letter symbols and abbreviations ...................................................... 38

A.1 Letter symbols ...................................................................................................... 38

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oSIST prEN IEC 60393-4:2023
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
POTENTIOMETERS FOR USE IN ELECTRICAL EQUIPMENT –
Part 4: Sectional specification:
Single-turn rotary power potentiometers
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 in

addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,

Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). 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. IEC collaborates closely with the International Organization for

Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence between

any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses

arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.

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) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent

rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60393-3 has been prepared by IEC technical committee 40:

Capacitors and resistors for electronic equipment.

This third edition cancels and replaces the second edition published in 1992 and constitutes a

technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) Revised all parts of the document based on the ISO/IEC Directives, Part 2:2018 (eighth

edition) and harmonized with other similar kinds of documents.

b) The document structure has been organized to follow new sectional specification structure

decided in TC 40

c) revision of the information on the assessment level EZ and FZ (zero nonconforming).

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oSIST prEN IEC 60393-4:2023
40/2988/CDV – 5 – IEC CDV 60393-4 © IEC 2022
The text of this International Standard is based on the following documents:
FDIS Report on voting
40/XX/FDIS 40/XX/RVD

Full information on the voting for the approval of this International Standard 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 http://www.iec.ch/standardsdev/publications.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

The National Committees are requested to note that for this document the stability date

is 2028

THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND WILL BE DELETED

AT THE PUBLICATION STAGE.
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oSIST prEN IEC 60393-4:2023
40/2988/CDV – 6 – IEC CDV 60393-4 © IEC 2022
1 POTENTIOMETERS FOR USE IN ELECTRICAL EQUIPMENT
3 Part 4: Sectional specification:
4 Single-turn rotary power potentiometers –
5 Methods and guidance
7 1 Scope

8 This standard is applicable to single-turn rotary power potentiometers wire-wound technology.

9 Enamelled, cemented, moulded, enclosed.

10 This specification is applicable to rotary potentiometers with nominal dissipation in excess of 10

11 Watts, the resistive element of which consists of a wire or a wound tape.

12 All the potentiometers prescribed by this specification are slider-driven without reduction. Their

13 stroke less than 360° is limited by stops.

14 This part of IEC 60393-4 prescribes preferred ratings and characteristics and selects from

15 IEC 60393-1, appropriate quality assessment procedures, tests and measuring methods. It

16 provides general performance requirements for this type of potentiometer
17 This standard gives the minimum performance requirements and test severities.
18 2 Normative reference

19 The following documents are referred to in the text in such a way that some or all of their content

20 constitutes requirements of this document. For dated references, only the edition cited applies.

21 For undated references, the latest edition of the referenced document (including any

22 amendments) applies
23 IEC 60027 (all parts), Letter symbols to be used in electrical technology
24 IEC 60050 (all parts), International Electrotechnical Vocabulary
25 IEC 60062, Marking codes for resistors and capacitors
26 IEC 60068-1:2013, Environmental testing – Part 1: General and guidance

27 IEC 60393-1:2008, Potentiometers for use in electronic equipment – Part 1: Generic specification

28 IEC 60068-2-1, Environmental testing – Part 2-1: Tests – Tests A: Cold
29 IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Tests B: Dry heat

30 IEC 60915, Capacitors and resistors for use in electronic equipment – Preferred dimensions of shaft

31 ends, bushes and for the mounting of single-hole, bush-mounted, shaft-operated electronic components

32 IEC 61439-1, Low-voltage switchgear and control gear assemblies – General rules (in

33 particular-temperature rise)

35 IEC 61193-2, Quality assessment systems – Part 2: Selection and use of sampling plans for

36 inspection of electronic components and package–
37 IEC 80000 (all parts), Quantities and units

38 IECQ 03-1:2012, Rules of procedure — Part 1: General Requirements for all IECQ Schemes

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40 3 Terms and definitions
42 3.1 Terms

43 For the purpose of this document, the terms and definitions given in IEC 60393-1, as well as the following, apply.

44 ISO and IEC maintain terminological databases for use in standardization at the following addresses:

45 • IEC Electropedia: available at https://www.electropedia.org/
46 • ISO Online browsing platform: available at https://www.iso.org/obp
47 3.1.1 Potentiometer

49 Component for use as a voltage divider with three terminals of which two are connected to the

50 ends of a resistive element and the third is connected to a moving contact which can be

51 moved mechanically along the resistive element.
53 3.1.2 Rheostat
54 Rheostat which is a variable resistor with two terminals
Figure 1 – schematic view
61 3.1.3 Total Resistance (Rt)
62 Total resistance is the resistance between terminal a and c (Rac)

63 Resistance value for which the variable resistor has been designed and which is generally

64 marked upon the variable resistor
65 3.1.4 Minimum resistance

66 The resistance measured between the wiper terminal and any terminal with the shaft positioned

67 to give the minimum value
68 3.1.5 End resistance

69 The resistance measured between the wiper terminal and an end terminal with the shaft

70 positioned at the corresponding end point.
71 3.1.6 Category dissipation

72 Fraction of the rated dissipation exactly defined by the relevant specification, applicable at the

73 upper category temperature, taking account of the derating curve prescribed by the relevant

74 specification
75 3.1.7 Nominal temperature
76 Ambient temperature
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77 3.1.8 Nominal dissipation (Pn)

78 Power dissipated over the entire resistive element in continuous operation, at the rated service

79 temperature
80 3.1.9 Shaft
81 The mechanical input element of the variable resistor
82 4 Preferred characteristics
83 4.1 General

84 The values given in detail specifications shall preferably be selected from the following.

85 4.2 Style and dimensions
86 4.2.3 Preferred outline dimensions
88 The dimensions of potentiometer are shown in Figure 2,
99 b
100
101
102
103
104
105
106
107
108
109
110
Figure 2 – Outline drawing and dimensions
111
112
113 The drawing shall give the following details:

114 – the dimensions of the shaft and bush. These may be given either on the outline drawing or by

115 reference to IEC 60915.
116 – any locating devices;
117 – the total mechanical travel;
118 – the effective electrical travel;
119 – the angle of ineffective mechanical travel;
120 – the dimensions and the location of terminations;

121 – the dimensions which shall be measured in accordance with IEC 60393-1:2008, 4.4.2;

122 – any other dimensional information which will adequately describe the potentiometer.

123 All dimensions shall preferably be stated in millimetres, however, when the original dimensions

124 are given in inches, the converted metric dimensions in millimetres shall be added.

125 When the potentiometer is not designed for use on printed boards, this shall be clearly indicated

126 in the detail specification.
127
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128 4.3 Preferred climatic categories

129 The potentiometers covered by this specification are classified into climatic categories according

130 to the general rules given in IEC 60068-1:2013, Annex A.

131 The lower and upper category temperature and the duration of the damp heat, steady state test

132 shall be chosen from the following:
133 Lower category temperature: -65 °C, -55 °C, -40 °C, -25 °C and -10 °C.
134 Upper category temperature: +70 °C, +85 °C, +100 °C, +125 °C, +155°C,
135 +175 °C and +200 °C
136 Duration of the damp heat, steady state test: 4, 10, 21 and 56 days.

137 The severities for the cold and dry heat tests are the lower and upper category temperatures

138 respectively. Because of the construction of some potentiometers these temperatures will occur

139 between two of the preferred temperatures given in IEC 60068-2-1:2007 and IEC 60068-2-

140 2:2007. In this case the nearest preferred temperature within the actual temperature range of

141 the potentiometer shall be chosen for this severity.
142 4.4 Resistance law
143 See 6.5
144 4.5 Nominal total resistance
145 See IEC 60393-1:2008, 2.3.2.
146 4.6 Tolerances on nominal total resistance

147 The preferred tolerances on nominal total resistance shall be taken from the series specified in

148 IEC 60063 (E24 – E12 – E6)
149 ± 20 %, ± 10 %, ± 5 %,
150 4.7 Rated dissipation
151 The preferred values of rated dissipation at 70 °C, are:

152 10 W, 16 W, 25 W, 40 W, 50 W, 63 W, 80 W, 100 W, 125 W, 160 W, 250 W, 315 W, 400 W, 500 W, 630

153 W, 800 W and 1 000 W
154

155 The derated values of dissipation at temperatures in excess of 70 °C shall be as indicated by

156 the curve as shown in Figure 3.
157
158
159
160
161
162
163
164
165
166 100
167
168
169 %P Αop
max
170
171
172
173
174 0
175 ϑlow 70 °C ϑupp
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176
177 Figure 3 – Rated dissipation curve
178

179 A larger area of operation may be given in the detail specification, provided it includes all the

180 area given above. In this event the detail specification shall state the maximum allowable

181 dissipation at temperatures other than 70 °C. All break points on the curve shall be verified by

182 test.
183

184 An example of a derating curve having a larger area of operation is given in Figure 4.

185 In certain circumstances, the rated dissipation may continue up to the upper category

186 temperature.
187
188
189
190 120
191
192
193
194 %P Αop
max
195
196
197
198
199 0

200 ϑlow 70 °C ϑupp

201
202
203 Figure 4 – Rated dissipation curve (example of larger area)
204
205 4.8 Limiting element voltage
206 The preferred values of DC or AC r.m.s. limiting element voltage Umax are:
207 160 V; 250 V; 400 V; 630 V; 1 000 V and 1 600 V.
208
209 4.9 Insulation voltage

210 The detail specification shall prescribe the value of the insulation voltage, rounded off to the

211 nearest 10 V. The numerical value of the insulation voltage shall be:
212 – Normal air pressure: ≥ 1,42 times the limiting element voltage
213 – Low air pressure (at 8 kPa): ≥ two-thirds the value at normal air pressure
214
215 4.10 Number of cycles of operation
216 The preferred number of cycles of operation are:
5 5 5
217 Single turn/continuous rotation: 1,25 x 10 , 2,5 x 10 or 5 x 10
218 4.11 Spindle rotational speed

219 The preferred spindle rotational speeds in revolutions per minute (r.p.m.) are:

220 – 40 ± 5
221
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222 5 Tests and test severities
223 5.1 General
224

225 The detail specification shall specify the method of mounting to be applied for the voltage proof

226 and the insulation resistance tests and
...