Aerospace series - Connectors, electrical, circular, scoop-proof, triple start threaded coupling, operating temperature 175 °C or 200 °C continuous - Part 001: Technical specification

This document specifies the general characteristics, the conditions for qualification, acceptance and quality assurance, as well as the test programs and groups for threaded ring coupling circular connectors, fire resistant, intended for use in a temperature range from -65 °C to 175 °C continuous or 200 °C continuous according to the classes.

Luft- und Raumfahrt - Elektrische Rundsteckverbinder, kontaktgeschützt, dreigängige Gewinde-Schnellkupplung, Betriebstemperatur 175 °C oder 200 °C konstant - Teil 001: Technische Lieferbedingungen

Série aérospatiale - Connecteurs électriques circulaires, à contacts protégés, à accouplement par filetage, à pas rapide à trois filets, température d'utilisation 175 °C ou 200 °C continu - Partie 001 : Spécification technique

Le présent document spécifie les caractéristiques générales, les conditions de qualification, d’acceptation et d’assurance qualité, ainsi que les programmes et les groupes d’essais des connecteurs circulaires à accouplement par bague filetée, résistants au feu, destinés à une utilisation dans une plage de températures comprises entre -65 °C et 175 °C continu, ou 200 °C continu suivant les classes.

Aeronavtika - Konektorji, električni, okrogli, zaščiten kontakt, hitra spojka z navojem, stalna delovna temperatura 175 °C ali 200 °C - 001. del: Tehnična specifikacija

General Information

Status
Published
Public Enquiry End Date
20-Oct-2021
Publication Date
19-Sep-2022
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
16-Sep-2022
Due Date
21-Nov-2022
Completion Date
20-Sep-2022

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SLOVENSKI STANDARD
SIST EN 3645-001:2022
01-november-2022
Nadomešča:
SIST EN 3645-001:2019
Aeronavtika - Konektorji, električni, okrogli, zaščiten kontakt, hitra spojka z
navojem, stalna delovna temperatura 175 °C ali 200 °C - 001. del: Tehnična
specifikacija

Aerospace series - Connectors, electrical, circular, scoop-proof, triple start threaded

coupling, operating temperature 175 °C or 200 °C continuous - Part 001: Technical

specification

Luft- und Raumfahrt - Elektrische Rundsteckverbinder, kontaktgeschützt, dreigängige

Gewinde-Schnellkupplung, Betriebstemperatur 175 °C oder 200 °C konstant - Teil 001:

Technische Lieferbedingungen
Série aérospatiale - Connecteurs électriques circulaires, à contacts protégés, à

accouplement par filetage, à pas rapide à trois filets, température d'utilisation 175 °C ou

200 °C continu - Partie 001 : Spécification technique
Ta slovenski standard je istoveten z: EN 3645-001:2022
ICS:
31.220.10 Vtiči in vtičnice, konektorji Plug-and-socket devices.
Connectors
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
SIST EN 3645-001:2022 en,fr,de

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

---------------------- Page: 1 ----------------------
SIST EN 3645-001:2022
---------------------- Page: 2 ----------------------
SIST EN 3645-001:2022
EN 3645-001
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2022
EUROPÄISCHE NORM
ICS 49.060 Supersedes EN 3645-001:2019
English Version
Aerospace series - Connectors, electrical, circular, scoop-
proof, triple start threaded coupling, operating
temperature 175 °C or 200 °C continuous - Part 001:
Technical specification

Série aérospatiale - Connecteurs électriques Luft- und Raumfahrt - Elektrische Rundsteckverbinder,

circulaires, à contacts protégés, à accouplement par kontaktgeschützt, dreigängige Gewinde-

filetage, à pas rapide à trois filets, température Schnellkupplung, Betriebstemperatur 175 °C oder 200

d'utilisation 175 °C ou 200 °C continu - Partie 001 : °C konstant - Teil 001: Technische Lieferbedingungen

Spécification technique
This European Standard was approved by CEN on 22 November 2021.

CEN 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 CEN

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 CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3645-001:2022 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
Contents Page

European foreword ...................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

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

2 Normative references .................................................................................................................................... 6

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

4 Description ........................................................................................................................................................ 7

4.1 General................................................................................................................................................................ 7

4.2 Receptacle.......................................................................................................................................................... 8

4.3 Plug ...................................................................................................................................................................... 8

4.4 Materials and surface treatment ............................................................................................................... 8

4.4.1 General................................................................................................................................................................ 8

4.4.2 Housing ............................................................................................................................................................... 8

4.4.3 Contacts .............................................................................................................................................................. 8

4.4.4 Non-metallic materials ................................................................................................................................. 9

4.4.5 Surfaces treatments ....................................................................................................................................... 9

5 Design .................................................................................................................................................................. 9

5.1 Housings ............................................................................................................................................................. 9

5.2 Inserts ............................................................................................................................................................... 10

6 Definition drawings and masses ............................................................................................................. 10

6.1 General.............................................................................................................................................................. 10

6.2 Receptacle mating dimensions ................................................................................................................ 10

6.3 Plug mating dimensions ............................................................................................................................. 13

6.4 Receptacle and plug polarization ............................................................................................................ 16

6.5 Dimensions of the rear part of the connectors .................................................................................. 17

6.5.1 Accessory interface dimensions .............................................................................................................. 17

6.5.2 Size 8 cavity - rear dimensions ................................................................................................................ 19

6.6 Contact arrangements ................................................................................................................................. 20

6.7 Contact dimensions ...................................................................................................................................... 66

6.7.1 Removable contacts ..................................................................................................................................... 66

6.7.2 Fixed contacts ................................................................................................................................................. 66

7 Tests ................................................................................................................................................................... 67

7.1 Tests according to EN 2591-100 .............................................................................................................. 67

7.2 Special tests ..................................................................................................................................................... 81

7.2.1 Lanyard release connectors ...................................................................................................................... 81

7.2.2 Resistance to fluids ...................................................................................................................................... 81

7.3 Gauges to test the holding force of the grounding spring system of the housing .................. 83

7.4 Gauges to test the stability of male contacts in insert ..................................................................... 84

8 Quality assurance ......................................................................................................................................... 85

8.1 General.............................................................................................................................................................. 85

8.2 Qualification ................................................................................................................................................... 85

8.2.1 General.............................................................................................................................................................. 85

8.2.2 For MIL-DTL-38999 QPL manufacturer ................................................................................................ 86

8.2.3 For non MIL-DTL-38999 QPL manufacturer ....................................................................................... 86

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SIST EN 3645-001:2022
EN 3645-001:2022 (E)

8.2.4 Sampling and definition of specimens .................................................................................................. 87

8.2.5 Preparation of specimens .......................................................................................................................... 88

8.2.6 Program of qualification tests .................................................................................................................. 89

8.3 Maintenance of qualification ................................................................................................................. 103

8.3.1 General .......................................................................................................................................................... 103

8.3.2 Recognition of MIL-DTL-38999 ............................................................................................................ 103

8.3.3 Fuel resistant class .................................................................................................................................... 104

8.3.4 Sampling distribution .............................................................................................................................. 104

8.4 Routine tests during production .......................................................................................................... 104

8.5 Inspections ................................................................................................................................................... 105

8.6 Value added distributors ........................................................................................................................ 105

9 Designation and marking ....................................................................................................................... 105

9.1 General principle of designation .......................................................................................................... 105

9.2 Marking ......................................................................................................................................................... 105

10 Delivery conditions ................................................................................................................................... 106

11 Packaging ...................................................................................................................................................... 106

12 Storage ........................................................................................................................................................... 106

Bibliography .............................................................................................................................................................. 107

---------------------- Page: 5 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
European foreword

This document (EN 3645-001:2022) has been prepared by the Aerospace and Defence Industries

Association of Europe — Standardization (ASD-STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this

document has received the approval of the National Associations and the Official Services of the

member countries of ASD, prior to its presentation to CEN.

This document shall be given the status of a national standard, either by publication of an identical

text or by endorsement, at the latest by March 2023, and conflicting national standards shall be

withdrawn at the latest by March 2023.

Attention is drawn to the possibility that some of the elements of this document may be the subject

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

This document supersedes EN 3645-001 :2019.

The main changes with respect to the previous edition are listed in the following table.

Table X — Main changes introduced
prEN/EN Edition Publication Modification
Number Date
prEN 3645 P5 2021-12-01 Introduction of Hexavalent Chromium free (in both
-001 manufacturing process and final product) plating classes and
related compatibility testing with legacy Cadmium plated items
Addition of optional marking for insulators according to MIL
standard

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this document: Austria, Belgium, Bulgaria, Croatia,

Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,

Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Türkiye and the United Kingdom.
---------------------- Page: 6 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
Introduction

This family of connectors is derived from MIL-DTL-38999 series III, with which it is intermateable and

interchangeable. It is particularly suitable for use in zones of severe environmental conditions on board

aircraft, applying EN 2282.
These connectors are distinguishable from MIL-DTL-38999 by:
 a compatibility with size 8 power and quadrax contacts;
 self-extinguishing materials;
 compatibility with reduced diameter cables;
 additional reinforced fuel resistant insert type;
 additional insert with grounded cavities.
---------------------- Page: 7 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
1 Scope

This document specifies the general characteristics, the conditions for qualification, acceptance and

quality assurance, as well as the test programs and groups for threaded ring coupling circular

connectors, fire resistant, intended for use in a temperature range from -65 °C to 175 °C continuous or

200 °C continuous according to the classes.
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 2267-002, Aerospace series — Cables, electrical, for general purpose — Operating temperatures

between -55 °C and 260 °C — Part 002: General

EN 2346 (all parts), Aerospace series — Cable, electrical, fire resistant — Operating temperatures

between -65 °C and 260 °C

EN 2591-*, Aerospace series — Elements of electrical and optical connection — Test methods

EN 3155-001:2016, Aerospace series — Electrical contacts used in elements of connection — Part 001:

Technical specification

EN 3197, Aerospace series — Design and installation of aircraft electrical and optical interconnection

systems

EN 3645-002, Aerospace series — Connectors, electrical, circular, scoop-proof, triple start threaded

coupling, operating temperature 175 °C or 200 °C continuous — Part 002: Specification of performance

and contact arrangements

EN 3909, Aerospace series — Test fluids and test methods for electrical and optical components and sub-

assemblies

ISO 68-1, ISO general purpose screw threads — Basic profile — Part 1: Metric screw threads

ISO 261, ISO general purpose metric screw threads — General plan

ISO 262, ISO general purpose metric screw threads — Selected sizes for screws, bolts and nuts

ISO 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general

purpose external and internal screw threads — Medium quality

ISO 27874, Metallic and other inorganic coatings — Electrodeposited gold and gold alloy coatings for

electrical, electronic and engineering purposes — Specification and test methods
* All parts quoted in this document.

Published as ASD-STAN Standard at the date of publication of this document by AeroSpace and Defence

industries Association of Europe — Standardization (ASD-STAN), https://www.asd-stan.org/.

Published by: ISO International Organization for Standardization http://www.iso.ch/.

---------------------- Page: 8 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)

MIL-DTL-38999, Connectors, electrical, circular, miniature, high density, quick disconnect (bayonet,

threaded, and breech coupling), environment resistant, removable crimp and hermetic solder contacts,

general specification for

MIL-DTL-38999/62, Sealing boot, size 8, pin or socket, shielded crimp contacts, electrical connector,

circular, metric
MIL-HDBK-454, General guidelines for electronic equipment
MIL-STD-1373, Screw-thread, modified, 60°, stub, double

MIL-STD-1560, Defence logistics agency: Insert Arrangements for MIL-DTL-38999, MIL-DTL-27599, and

SAE-AS29600 Series A Electrical Circular Connectors

TR 4865, Aerospace series — Suitable cable outlet to be mated on EN 3645 connector (layout type: 21R48)

for the qualification of electrical contact product standards EN 3155-065 and EN 3155-083

3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 2591-100 apply.

ISO and IEC maintain terminological 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/
4 Description
4.1 General

Different variants of materials, housings and contact arrangements are provided according to the

classes depending on the service conditions.
The pair of connectors is characterized:
 by shell-to-shell bottoming;
 by its triple threaded and self-locking coupling system;

 by plugs with shielding ring providing protection against radioelectrical interference;

 by the scoop-proof shells.
These connectors use the following contacts:
 crimped sizes 22, 20, 16, 12, 10 and 8;
 soldered (model Y) sizes 22, 20, 16 and 12;
Published by: DEFENSE LOGISTICS AGENCY DLA Land and Maritime (US)
https://landandmaritimeapps.dla.mil/Programs/MilSpec/DocSearch.aspx.

Published as ASD-STAN Technical Report at the date of publication of this document by AeroSpace and Defence

industries Association of Europe — Standardization (ASD-STAN), http://www.asd-stan.org/.

---------------------- Page: 9 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
 coaxial crimped or soldered sizes 16, 12 and 8;
For arrangements comprising the letter G or

 triaxial crimped or soldered size 8; Q, all contacts are grounded to the receptacle

housing
 quadrax crimped size 8.
The receptacles and plugs contain either male contacts or female contacts.

The contacts fitted in the class Y receptacles are exclusively of the male solder type.

The connectors are polarized by means of keyways and keys; polarization shall be obtained before the

male contacts enter the insert of the female contacts and before the coupling ring is engaged. The

position of the keying arrangement is given in Table 7.

The visual check of coupling is obtained by masking of a red colour band on the receptacle.

4.2 Receptacle
The receptacle housing may be attached:
 square flange;

 nut, with sealing by O-ring at the attachment; round soldered or brazed flange for class Y connectors.

4.3 Plug

The coupling ring is permanently fitted to the plug and allows coupling and uncoupling of the

connectors. The lanyard release version may also be uncoupled by pulling on the lanyard.

The plug is fitted with a self-locking mechanism and a grounding spring device ensuring electrical

continuity between the coupled connector housings.
An anti-decoupling device shall be provided to maintain complete coupling.
4.4 Materials and surface treatment
4.4.1 General

When dissimilar metals are in close contact, adequate protection against corrosion shall be used for the

electromotive force of the cell not to exceed 0,25 V (see EN 3197).
4.4.2 Housing

The material of the housings for the connectors and fittings may be either aluminium alloy, passivated

stainless steel or composite. Aluminium alloy and composite shall be plated as defined by the class

(composite coupling rings and Hex nut may be unplated) (see EN 3645-002).
4.4.3 Contacts

Unless otherwise specified, the non-removable contacts shall be in ferrous alloy for class Y and in

copper alloy for the other classes.

They shall be gold-plated on an appropriate undercoat. Selective protection is authorised provided that

it is sufficient to ensure that the specified performance is achieved.

Measurement of the thickness of the protective plating shall be effected in accordance with ISO 27874.

NOTE In the past, the determination of coating thickness was described in ISO 4524-1, which has been withdrawn.

For removable contacts, see EN 3645-002.
---------------------- Page: 10 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
4.4.4 Non-metallic materials

The materials used for insert, seals and grommets shall have a hardness and mechanical and electrical

characteristics consistent with the required use.
4.4.5 Surfaces treatments
Label chrome 6 free (not applicable for class W & J):

None of the hexavalent chromium compounds listed hereafter shall be added by any actor of the Supply

Chain or used in the manufacturing process.

The manufacturing process begins with the creation of the materials from which the design is made.

Manufacturing processes include treating (such as heat treating or plating), machining, moulding or

reshaping the material.
Table 2 — Hexavalent chromium compound list
Substance name CAS number
Acids generated from chromium trioxide and their 7738-94-5
oligomers. Names of the acids and their oligomers:
13530-68-2
chromic acid, dichromic acid, oligomers of chromic
acid and dichromic acid.
Chromium trioxide 1333-82-0
Potassium dichromate 7778-50-9
Sodium chromate 7775-11-3
Sodium dichromate 7789-12-0
10588-01-9
Dichromium tris(chromate) 24613-89-6
Pentazinc chromate octahydroxide 49663-84-5
Potassium hydroxyoctaoxodizincatedichromate 11103-86-9
Strontium chromate 7789-06-2
5 Design
5.1 Housings

The connector housings shall be one-piece. They shall contain teeth at the rear over their entire periphery

and shall accommodate the rear accessories. The receptacle shall be fitted with a seal for sealing the

coupled housings.

Jam-nut receptacles shall contain an O-ring seal. The nut shall have holes for the passage of locking wire.

During coupling the grounding spring shall be engaged a minimum of 1,02 mm in the receptacle before

the contacts engage.

5) The CAS Registry Number, also referred to as CASRN or CAS Number, is a unique numerical identifier assigned

by the Chemical Abstracts Service, a division of the American Chemical Society.
---------------------- Page: 11 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)

Except for the triple start threads, which shall conform to standard MIL-STD-1373, threads shall

conform to standards ISO 68-1, ISO 261, ISO 262 and ISO 965-2.

The coupling ring shall be designed so that the male and female contacts engage when it is turned in a

clockwise direction and disengage when turned anticlockwise. The coupling threads may have a

lubricant applied during manufacture.

Full locking of the connectors shall occur at about 360°. On completion of tightening of the coupling

ring, mechanical contact shall exist between the receptacle and plug housings. A red band shall be

located on the receptacle so as to be visible when unmated and fully covered when completely mated.

The receptacle has five keyways which engage with corresponding keys on the plug. The major key is

fixed and is wider than the others. Polarization is ensured by the different positions which the minor

keys may take. The position of the insert is fixed relative to the major key.

A blue-coloured band indicating that the crimped contacts of the connectors are rear-releasable shall be

provided:
 in front of the flange on square flange receptacles;
 on the flange of jam-nut receptacles;
 on the coupling ring of plugs.

This band shall be positioned so that at least one is visible when the connectors are fitted and when

they are mated or unmated. Hermetic receptacles do not require blue colour band.
5.2 Inserts

The insert for contacts shall be non-removable; it shall be mechanically held in the housing. Sealing

shall be provided between the housing and insert.

The front face of the insert shall be such that sealing is ensured when the connectors are coupled.

The interfacial seal of the insert of the male contacts shall be bonded on the hard insert.

The grommet shall permit sealing for all cable diameters indicated in EN 3645-002 and shall not be

removable.
The mechanical contacts retention system shall be integrated in the hard insert.

The design of non-hermetic connectors shall permit individual installation of the contacts without

removal of the insert or grommet. Fitting and removal of the contacts shall be from the rear with the

tools specified in the contact product standards.

Contact position identification shall be permanent and contrasted on the front face of the insert or the

interfacial seal and on the rear face of the grommet as indicated in 6.6.
The marking shall not be recessed or raised on the surfaces providing a seal.
6 Definition drawings and masses
6.1 General

The general dimensions and the masses of receptacles, plugs and protective covers are given in the

product standards.
6.2 Receptacle mating dimensions

The mating dimensions of receptacles are shown in Figure 1 and details V and W as well as in Table 3 and

Table 4.
---------------------- Page: 12 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
Dimensions and tolerances are in millimetres.
Key

a The distance between the front face of the shell and the point where the right end of a gauge with a diameter

equal to the nominal diameter of a male contact comes into contact with the elastic part of the female contact.

Figure 1 — Receptacle — Coupling dimensions
---------------------- Page: 13 ----------------------
SIST EN 3645-001:2022
EN 3645-001:2022 (E)
Table 3 — Receptacle — Dimensions (1 of 2)
Housing A dia. B dia. C dia. D dia. D dia. E dia. E dia. F dia.
size (except classes (classes J and (except classes (classes J and
J and M) M only) J and M) M only)
+ 0,13
max. max.
−0,25
14,42 11,36 11,43 12,63 12,70
09 14,55 7,24 15,88
14,14 11,20 11,20 12,34 12,34
17,60 14,61 14,68 15,88 15,95
11 17,73 10,49 19,05
17,32 14,45 14,45 15,60 15,60
20,77 17,45 17,52 19,66 19,73
13 20,90 13,39 22,23
20,49 17,30 17,30 19,38 19,38
23,95 20,63 20,70 22,84 22,91
...

SLOVENSKI STANDARD
oSIST prEN 3645-001:2021
01-oktober-2021
Aeronavtika - Konektorji, električni, okrogli, zaščiten kontakt, hitra spojka z
navojem, stalna delovna temperatura 175 °C ali 200 °C - 001. del: Tehnična
specifikacija

Aerospace series - Connectors, electrical, circular, scoop-proof, triple start threaded

coupling, operating temperature 175 °C or 200 °C continuous - Part 001: Technical

specification

Luft- und Raumfahrt - Elektrische Rundsteckverbinder, kontaktgeschützt, dreigängige

Gewinde-Schnellkupplung, Betriebstemperatur 175 °C oder 200 °C konstant - Teil 001:

Technische Lieferbedingungen
Ta slovenski standard je istoveten z: prEN 3645-001
ICS:
31.220.10 Vtiči in vtičnice, konektorji Plug-and-socket devices.
Connectors
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
oSIST prEN 3645-001:2021 en,fr,de

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

---------------------- Page: 1 ----------------------
oSIST prEN 3645-001:2021
---------------------- Page: 2 ----------------------
oSIST prEN 3645-001:2021
DRAFT
EUROPEAN STANDARD
prEN 3645-001
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2021
ICS 49.060 Will supersede EN 3645-001:2019
English Version
Aerospace series - Connectors, electrical, circular, scoop-
proof, triple start threaded coupling, operating
temperature 175 °C or 200 °C continuous - Part 001:
Technical specification

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-

STAN.

If this draft becomes a European Standard, CEN 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.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

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

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 3645-001:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
Contents Page

European foreword ...................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

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

2 Normative references .................................................................................................................................... 6

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

4 Description ........................................................................................................................................................ 7

4.1 General................................................................................................................................................................ 7

4.2 Receptacle.......................................................................................................................................................... 8

4.3 Plug ...................................................................................................................................................................... 8

4.4 Materials and surface treatment ............................................................................................................... 8

4.4.1 General................................................................................................................................................................ 8

4.4.2 Housing ............................................................................................................................................................... 8

4.4.3 Contacts .............................................................................................................................................................. 9

4.4.4 Non-metallic materials ................................................................................................................................. 9

4.4.5 Surfaces treatments ....................................................................................................................................... 9

5 Design ................................................................................................................................................................ 10

5.1 Housings ........................................................................................................................................................... 10

5.2 Inserts ............................................................................................................................................................... 10

6 Definition drawings and masses ............................................................................................................. 11

6.1 General.............................................................................................................................................................. 11

6.2 Receptacle mating dimensions ................................................................................................................ 11

6.3 Plug mating dimensions ............................................................................................................................. 14

6.4 Receptacle and plug polarization ............................................................................................................ 17

6.5 Dimensions of the rear part of the connectors .................................................................................. 18

6.5.1 Accessory interface dimensions .............................................................................................................. 18

6.5.2 Size 8 cavity - rear dimensions ................................................................................................................ 20

6.6 Contact arrangements ................................................................................................................................. 21

6.7 Contact dimensions ...................................................................................................................................... 67

6.7.1 Removable contacts ..................................................................................................................................... 67

6.7.2 Fixed contacts ................................................................................................................................................. 67

7 Tests ................................................................................................................................................................... 68

7.1 Tests according to EN 2591-100 .............................................................................................................. 68

7.2 Special tests ..................................................................................................................................................... 82

7.2.1 Lanyard release connectors ...................................................................................................................... 82

7.2.2 Resistance to fluids ...................................................................................................................................... 82

7.3 Gauges to test the holding force of the grounding spring system of the housing .................. 84

7.4 Gauges to test the stability of male contacts in insert ..................................................................... 85

8 Quality assurance ......................................................................................................................................... 86

8.1 General.............................................................................................................................................................. 86

8.2 Qualification ................................................................................................................................................... 86

8.2.1 General.............................................................................................................................................................. 86

8.2.2 For MIL-DTL-38999 QPL manufacturer ................................................................................................ 87

8.2.3 For non MIL-DTL-38999 QPL manufacturer ....................................................................................... 87

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8.2.4 Sampling and definition of specimens .................................................................................................. 88

8.2.5 Preparation of specimens .......................................................................................................................... 89

8.2.6 Program of qualification tests .................................................................................................................. 90

8.3 Maintenance of qualification ................................................................................................................. 105

8.3.1 General .......................................................................................................................................................... 105

8.3.2 Recognition of MIL-DTL-38999 ............................................................................................................ 105

8.3.3 Fuel resistant class .................................................................................................................................... 106

8.3.4 Sampling distribution .............................................................................................................................. 106

8.4 Routine tests during production .......................................................................................................... 106

8.5 Inspections ................................................................................................................................................... 107

8.6 Value added distributors ........................................................................................................................ 107

9 Designation and marking ....................................................................................................................... 107

9.1 General principle of designation .......................................................................................................... 107

9.2 Marking ......................................................................................................................................................... 107

10 Delivery conditions ................................................................................................................................... 108

11 Packaging ...................................................................................................................................................... 108

12 Storage ........................................................................................................................................................... 108

Bibliography .............................................................................................................................................................. 109

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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
European foreword

This document (prEN 3645-001:2021) has been prepared by the Aerospace and Defence Industries

Association of Europe — Standardization (ASD-STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this

document has received the approval of the National Associations and the Official Services of the

member countries of ASD-STAN, prior to its presentation to CEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 3645-001:2019.
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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
Introduction

This family of connectors is derived from MIL-DTL-38999 series III, with which it is intermateable and

interchangeable. It is particularly suitable for use in zones of severe environmental conditions on board

aircraft, applying EN 2282.
These connectors are distinguishable from MIL-DTL-38999 by:
 a compatibility with size 8 power and quadrax contacts;
 self-extinguishing materials;
 compatibility with reduced diameter cables;
 additional reinforced fuel resistant insert type;
 additional insert with grounded cavities.
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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
1 Scope

This document specifies the general characteristics, the conditions for qualification, acceptance and

quality assurance, as well as the test programs and groups for threaded ring coupling circular

connectors, fire resistant, intended for use in a temperature range from -65 °C to 175 °C continuous or

200 °C continuous according to the classes.
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 2267-002, Aerospace series — Cables, electrical, for general purpose — Operating temperatures

between -55 °C and 260 °C — Part 002: General

EN 2346 (all parts), Aerospace series — Cable, electrical, fire resistant — Operating temperatures

between -65 °C and 260 °C

EN 2591- , Aerospace series — Elements of electrical and optical connection — Test methods

EN 3155-001:2016, Aerospace series — Electrical contacts used in elements of connection — Part 001:

Technical specification

EN 3197, Aerospace series — Design and installation of aircraft electrical and optical interconnection

systems

EN 3645-002, Aerospace series — Connectors, electrical, circular, scoop-proof, triple start threaded

coupling, operating temperature 175 °C or 200 °C continuous — Part 002: Specification of performance

and contact arrangements

EN 3909, Aerospace series — Test fluids and test methods for electrical and optical components and sub-

assemblies

EN 9133, Aerospace series — Quality management systems — Qualification procedure for aerospace

standard products

ISO 68-1, ISO general purpose screw threads — Basic profile — Part 1: Metric screw threads

ISO 261, ISO general purpose metric screw threads — General plan

ISO 262, ISO general purpose metric screw threads — Selected sizes for screws, bolts and nuts

ISO 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general

purpose external and internal screw threads — Medium quality

ISO 27874, Metallic and other inorganic coatings — Electrodeposited gold and gold alloy coatings for

electrical, electronic and engineering purposes — Specification and test methods

Published as ASD-STAN Standard at the date of publication of this document by AeroSpace and Defence

industries Association of Europe — Standardization (ASD-STAN), http://www.asd-stan.org/.

All parts quoted in this document.

Published by: ISO International Organization for Standardization http://www.iso.ch/.

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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)

MIL-DTL-38999, Connectors, electrical, circular, miniature, high density, quick disconnect (bayonet,

threaded, and breech coupling), environment resistant, removable crimp and hermetic solder contacts,

general specification for

MIL-DTL-38999/62, Sealing boot, size 8, pin or socket, shielded crimp contacts, electrical connector,

circular, metric
MIL-HDBK-454, General guidelines for electronic equipment
MIL-STD-1373, Screw-thread, modified, 60°, stub, double

MIL-STD-1560, Defence logistics agency: Insert Arrangements for MIL-DTL-38999, MIL-DTL-27599, and

SAE-AS29600 Series A Electrical Circular Connectors

TR 4865, Aerospace series — Suitable cable outlet to be mated on EN 3645 connector (layout type: 21R48)

for the qualification of electrical contact product standards EN 3155-065 and EN 3155-083

3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 2591-100 apply.

ISO and IEC maintain terminological 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/
4 Description
4.1 General

Different variants of materials, housings and contact arrangements are provided according to the

classes depending on the service conditions.
The pair of connectors is characterized:
 by shell to shell bottoming;
 by its triple threaded and self-locking coupling system;

 by plugs with shielding ring providing protection against radioelectrical interference;

 by the scoop-proof shells.
Published by: DEFENSE LOGISTICS AGENCY DLA Land and Maritime (US)
https://landandmaritimeapps.dla.mil/Programs/MilSpec/DocSearch.aspx.

Published as ASD-STAN Technical Report at the date of publication of this document by AeroSpace and Defence

industries Association of Europe — Standardization (ASD-STAN), http://www.asd-stan.org/.

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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
These connectors use the following contacts:
 crimped sizes 22, 20, 16, 12, 10 and 8;
 soldered (model Y) sizes 22, 20, 16 and 12;
 coaxial crimped or soldered sizes 16, 12 and 8;
For arrangements comprising the letter G or
 triaxial crimped or soldered size 8;
Q, all contacts are grounded to the receptacle
housing
 quadrax crimped size 8.
The receptacles and plugs contain either male contacts or female contacts.

The contacts fitted in the class Y receptacles are exclusively of the male solder type.

The connectors are polarized by means of keyways and keys; polarization shall be obtained before the

male contacts enter the insert of the female contacts and before the coupling ring is engaged. The

position of the keying arrangement is given in Table 6.

The visual check of coupling is obtained by masking of a red colour band on the receptacle.

4.2 Receptacle
The receptacle housing may be attached:
 square flange;

 nut, with sealing by O-ring at the attachment; round soldered or brazed flange for class Y

connectors.
4.3 Plug

The coupling ring is permanently fitted to the plug and allows coupling and uncoupling of the

connectors. The lanyard release version may also be uncoupled by pulling on the lanyard.

The plug is fitted with a self-locking mechanism and a grounding spring device ensuring electrical

continuity between the coupled connector housings.
An anti-decoupling device shall be provided to maintain complete coupling.
4.4 Materials and surface treatment
4.4.1 General

When dissimilar metals are in close contact, adequate protection against corrosion shall be used for the

electromotive force of the cell not to exceed 0,25 V (see EN 3197).
4.4.2 Housing

The material of the housings for the connectors and fittings may be either aluminium alloy, passivated

stainless steel or composite. Aluminium alloy and composite shall be plated as defined by the class

(composite coupling rings and Hex nut may be unplated) (see EN 3645-002).
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4.4.3 Contacts

Unless otherwise specified, the non-removable contacts shall be in ferrous alloy for class Y and in

copper alloy for the other classes.

They shall be gold-plated on an appropriate undercoat. Selective protection is authorized provided that

it is sufficient to ensure that the specified performance is achieved.

Measurement of the thickness of the protective plating shall be effected in accordance with ISO 27874.

NOTE In the past, the determination of coating thickness was described in ISO 4524-1, which has been

withdrawn.
For removable contacts, see EN 3645-002.
4.4.4 Non-metallic materials

The materials used for insert, seals and grommets shall have a hardness and mechanical and electrical

characteristics consistent with the required use.
4.4.5 Surfaces treatments
Label chrome 6 free (not applicable for class W & J):

None of the hexavalent chromium compounds listed hereafter shall be added by any actor of the Supply

Chain or used in the manufacturing process.

The manufacturing process begins with the creation of the materials from which the design is made.

Manufacturing processes include treating (such as heat treating or plating), machining, moulding or

reshaping the material.
Table 1 — Hexavalent chromium compound list
Substance name CAS number
Acids generated from chromium trioxide and their 7738-94-5
oligomers. Names of the acids and their oligomers:
13530-68-2
chromic acid, dichromic acid, oligomers of chromic
acid and dichromic acid.
Chromium trioxide 1333-82-0
Potassium dichromate 7778-50-9
Sodium chromate 7775-11-3
Sodium dichromate 7789-12-0
10588-01-9
Dichromium tris(chromate) 24613-89-6
Pentazinc chromate octahydroxide 49663-84-5
Potassium hydroxyoctaoxodizincatedichromate 11103-86-9
Strontium chromate 7789-06-2

The CAS Registry Number, also referred to as CASRN or CAS Number, is a unique numerical identifier assigned

by the Chemical Abstracts Service, a division of the American Chemical Society.
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oSIST prEN 3645-001:2021
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5 Design
5.1 Housings

The connector housings shall be one-piece. They shall contain teeth at the rear over their entire periphery

and shall accommodate the rear accessories. The receptacle shall be fitted with a seal for sealing the

coupled housings.

Jam-nut receptacles shall contain an O-ring seal. The nut shall have holes for the passage of locking

wire.

During coupling the grounding spring shall be engaged a minimum of 1,02 mm in the receptacle before

the contacts engage.

Except for the triple start threads, which shall conform to standard MIL-STD-1373, threads shall

conform to standards ISO 68-1, ISO 261, ISO 262 and ISO 965-2.

The coupling ring shall be designed so that the male and female contacts engage when it is turned in a

clockwise direction and disengage when turned anticlockwise. The coupling threads may have a

lubricant applied during manufacture.

Full locking of the connectors shall occur at about 360°. On completion of tightening of the coupling

ring, mechanical contact shall exist between the receptacle and plug housings. A red band shall be

located on the receptacle so as to be visible when unmated and fully covered when completely mated.

The receptacle has five keyways which engage with corresponding keys on the plug. The major key is

fixed and is wider than the others. Polarization is ensured by the different positions which the minor

keys may take. The position of the insert is fixed relative to the major key.

A blue-coloured band indicating that the crimped contacts of the connectors are rear-releasable shall be

provided:
 in front of the flange on square flange receptacles;
 on the flange of jam-nut receptacles;
 on the coupling ring of plugs.

This band shall be positioned so that at least one is visible when the connectors are fitted and when

they are mated or unmated. Hermetic receptacles do not require blue colour band.
5.2 Inserts

The insert for contacts shall be non-removable; it shall be mechanically held in the housing. Sealing

shall be provided between the housing and insert.

The front face of the insert shall be such that sealing is ensured when the connectors are coupled. The

interfacial seal of the insert of the male contacts shall be bonded on the hard insert.

The grommet shall permit sealing for all cable diameters indicated in EN 3645-002 and shall not be

removable.
The mechanical contacts retention system shall be integrated in the hard insert.

The design of non-hermetic connectors shall permit individual installation of the contacts without

removal of the insert or grommet. Fitting and removal of the contacts shall be from the rear with the

tools specified in the contact product standards.

Contact position identification shall be permanent and contrasted on the front face of the insert or the

interfacial seal and on the rear face of the grommet as indicated in 6.6.
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The marking shall not be recessed or raised on the surfaces providing a seal.
6 Definition drawings and masses
6.1 General

The general dimensions and the masses of receptacles, plugs and protective covers are given in the

product standards.
6.2 Receptacle mating dimensions

The mating dimensions of receptacles are shown in Figure 1 and details V and W as well as in Table 2 and

Table 3.
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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
Dimensions and tolerances are in millimetres.
Key

a The distance between the front face of the shell and the point where the right end of a gauge with a diameter

equal to the nominal diameter of a male contact comes into contact with the elastic part of the female contact.

Figure 1 — Receptacle — Coupling dimensions
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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
Table 2 — Receptacle — Dimensions (1 of 2)
Housing A dia. B dia. C dia. D dia. D dia. E dia. E dia. F dia.
(except classes (classes J and (except classes (classes J and
size
J and M) M only) J and M) M only)
+ 0,13
max. max.
− 0,25
14,42 11,36 11,43 12,63 12,70
09 14,55 7,24 15,88
14,14 11,20 11,20 12,34 12,34
17,60 14,61 14,68 15,88 15,95
11 17,73 10,49 19,05
17,32 14,45 14,45 15,60 15,60
20,77 17,45 17,52 19,66 19,73
13 20,90 13,39 22,23
20,49 17,30 17,30 19,38 19,38
23,95 20,63 20,70 22,84 22,91
15 24,08 16,56 25,40
23,67 20,44 20,44 22,56 22,56
28,30 23,80 23,87 26,01 26,08
17 28,52 19,74 30,16
27,97 23,64 23,64 25,73 25,73
29,89 26,47 26,54 28,63 28,70
19 30,12 22,00 31,75
29,56 26,31 26,31 28,40 28,40
33,07 29,64 29,71 31,85 31,92
21 33,30 25,17 34,73
32,74 29,49 29,49 31,57 31,57
36,24 32,82 32,89 35,03 35,10
23 36,47 28,35 38,10
35,91 32,66 32,66 34,75 34,75
39,42 35,99 35,06 38,20 38,27
25 39,65 31,52 41,28
39,09 35,84 35,84 37,92 37,92
Table 2 — Receptacle — Dimensions (2 of 2)
M dia. N dia. P dia. R dia. S dia.
Contact
size
max.
1,35 1,88 0,97 1,70
22 0,71
1,27 1,75 0,89 1,60
1,91 2,44 1,32 2,26
20 0,97
1,83 2,31 1,24 2,16
2,49 3,02 1,88 2,84
16 1,52
2,41 2,90 1,80 2,74
3,30 3,84 2,69 3,66
12 2,34
3,23 3,71 2,62 3,56
4,09 4,62 3,48 4,45
10 3,12
4,01 4,50 3,40 4,34
6,50 7,06 5,84 6,81
8 5,49
6,38 6,93 5,77 6,71
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oSIST prEN 3645-001:2021
prEN 3645-001:2021 (E)
Table 3 — Receptacle — Thread
BB - Thread
External threading
Designation
Class 2A
Class 2A thread
See
Housing
Thread Apparent Actual External Diameter Diameter
size
Note
size pitch pitch diameter on side at thread end
inch inch inch max. min. max. min. max. min.
09 0,625 0 15,83 15,63 15,17 14,97 14,41 14,05
11 0,750 0 19,01 18,80 18,35 18,14 17,58 17,23
13 0,875 0 22,18 21,98 21,52 21,32 20,
...

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