Space product assurance - Wire wrapping of high-reliability electrical connections

This Standard specifies requirements for preparing and assembling parts to be joined by wire wrapping, as well as the selection, calibration, use and certification of wire wrapping tools.
The covered wire­wrapped connections are illustrated in Figure 1 1.
This type of connection is similar to “Class A preferred” or “modified” connection detailed in MIL STD 1130, and NASA NHB 5300.4(3H).
Only previously tested and qualified wire­wrapped connections are covered by this Standard, which includes four wire sizes from 24 AWG
to 30 AWG, and three terminal post sizes up to 1,78 mm maximum diagonal. A step-by step procedure is covered in the informative
Annex A.
The use of heavier gauge wire and larger terminals is not generally prohibited, but it is considered unlikely that for such dimensions the method of wire­wrapping would be chosen as the electrical interconnection technique. Instead it is assumed that wire larger than 24 AWG
will be multi-stranded and terminated by soldering in conformance with ECSS-Q-ST-70-08, or by crimping in conformance with ECSS-Q-ST-70-26.
Training and certification requirements for operators and inspectors are defined in clause 5.6.7 and in ECSS-Q-ST-20.
With effect from the date of approval, this Standard announces the adoption of the external document on a restricted basis for use in the European Cooperation for Space Standardization (ECSS) system.
This standard may be tailored for the specific characteristic and constraints of a space project in conformance with ECSS-S-ST-00.

Raumfahrtproduktsicherung - Umhüllung von Kabeln für hochzuverlässige elektrische Verbindungen

Assurance produit des projets spatiaux - Enveloppe de fils pour connexion électrique à fiabilité élevée

La présente norme spécifie les exigences applicables à la préparation et à l'assemblage de composants à relier par enveloppe de fils et traite également du choix, de l’étalonnage, de l’utilisation et de la certification de l’outillage pour les enveloppes de fils.
Les connexions avec enveloppe de fils traitées sont illustrées à la Figure 1-1.
Ce type de connexion est semblable aux connexions « Classe A recommandée » ou « modifiée » pour lesquelles de plus amples informations figurent dans les normes MIL-STD-1130 et NASA NHB 5300.4( 3H).
Seules les enveloppes de fils précédemment testées et qualifiées font l'objet de la présente norme, qui énumère quatre calibres de câbles allant de 24 à 30 AWG et trois dimensions de bornes allant jusqu’à 1,78 mm maximum en diagonale. Une procédure pas à pas est donnée à titre informatif dans l’Annexe A.
L’utilisation de câbles de calibre supérieur et de bornes de dimensions plus grandes n’est, d'une manière générale, pas proscrite. Cependant, dans ce cas, le choix de la méthode de l'enveloppe de fils pour réaliser l'interconnexion électrique est peu probable. Il est plus vraisemblable que les câbles d'un calibre supérieur à 24 AWG comportent plusieurs torons et soient terminés par une brasure conformément à l'ECSS-Q-ST-70-08, ou par sertissage conformément à l'ECSS-Q-ST-70-26.

Zagotavljanje varnih proizvodov v vesoljski tehniki - Spajanje z žičnim ovijanjem kontaktov visoko zanesljivih električnih konektorjev

Ta standard določa zahteve za pripravo in sestavljanje delov, ki se spajajo z žičnim ovijanjem, ter tudi za izbiro, kalibracijo, uporabo in potrjevanje orodij za spajanje z žičnim ovijanjem. Pokriti, z žico oviti konektorji so prikazani na sliki 1.1.  Ta tip konektorja je podoben konektorju »zaželen razred A« ali »spremenjen«, podrobno opisanem v dokumentih MIL STD 1130 in NASA NHB 5300.4(3H). V tem standardu so obravnavani samo predhodno preskušeni in kvalificirani z žico oviti konektorji, kar zajema štiri velikosti žic, in sicer od 24 AWG do 30 AWG, ter tri velikosti zaključnih priključkov do največje diagonalne mere 1,78 mm. Koraki postopka so opisani v informativnem dodatku A. Uporaba večje žice in večjih priključkov ni splošno prepovedana, a ni verjetno, da bi bila pri takih merah za tehniko električnega povezovanja izbrana metoda ovijanja z žico. Namesto tega se predvideva, da bo žica, večja od 24 AWG, imela več plasti in bo zaključena s spajkanjem v skladu s standardom ECSS-Q-ST-70-08 ali s stiskalnim spajanjem v skladu s standardom ECSS-Q-ST-70-26. Zahteve za usposabljanje in certificiranje upravljavcev in inšpektorjev so določene v točki 5.6.7 ter v standardu ECSS-Q-ST-20. Ta standard napoveduje sprejetje zunanjega dokumenta na omejeni podlagi za uporabo v sistemu evropskega sodelovanja za standardizacijo na področju vesolja (ECSS) z veljavnostjo od datuma odobritve. Ta standard se lahko prilagodi posameznim lastnostim in omejitvam vesoljskega projekta v skladu s standardom ECSS-S-ST-00.

General Information

Status
Published
Public Enquiry End Date
27-Feb-2014
Publication Date
01-Dec-2014
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
06-Nov-2014
Due Date
11-Jan-2015
Completion Date
02-Dec-2014

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Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 16602-70-30:2015
01-januar-2015
=DJRWDYOMDQMHYDUQLKSURL]YRGRYYYHVROMVNLWHKQLNL6SDMDQMH]åLþQLPRYLMDQMHP
NRQWDNWRYYLVRNR]DQHVOMLYLKHOHNWULþQLKNRQHNWRUMHY
Space product assurance - Wire wrapping of high-reliability electrical connections
Raumfahrtproduktsicherung - Umhüllung von Kabeln für hochzuverlässige elektrische
Verbindungen
Assurance produit des projets spatiaux - Enveloppe de fils pour connexion électrique à
fiabilité élevée
Ta slovenski standard je istoveten z: EN 16602-70-30:2014
ICS:
49.060 /HWDOVNDLQYHVROMVND Aerospace electric
HOHNWULþQDRSUHPDLQVLVWHPL equipment and systems
49.140 Vesoljski sistemi in operacije Space systems and
operations
SIST EN 16602-70-30:2015 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 16602-70-30:2015

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SIST EN 16602-70-30:2015


EUROPEAN STANDARD
EN 16602-70-30

NORME EUROPÉENNE

EUROPÄISCHE NORM
October 2014
ICS 49.140

English version
Space product assurance - Wire wrapping of high-reliability
electrical connections
Assurance produit des projets spatiaux - Enveloppe de fils Raumfahrtproduktsicherung - Umhüllung von Kabeln für
pour connexion électrique à fiabilité élevée hochzuverlässige elektrische Verbindungen
This European Standard was approved by CEN on 11 April 2014.

CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving
this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning
such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN and CENELEC
member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN and CENELEC member into its own language and notified to the CEN-CENELEC Management Centre
has the same status as the official versions.

CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,
Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.






CEN-CENELEC Management Centre:
Avenue Marnix 17, B-1000 Brussels
© 2014 CEN/CENELEC All rights of exploitation in any form and by any means reserved Ref. No. EN 16602-70-30:2014 E
worldwide for CEN national Members and for CENELEC
Members.

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SIST EN 16602-70-30:2015
EN 16602-70-30:2014 (E)
Table of contents
Foreword . 5
1 Scope . 6
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 9
3.1 Terms defined in other standards . 9
3.2 Terms specific to the present standard . 9
3.3 Abbreviated terms. 10
4 Principles . 11
5 Requirements . 12
5.1 Preparatory conditions . 12
5.1.1 Hazards, health and safety precautions . 12
5.1.2 Facilities . 12
5.1.3 Tools and equipment . 13
5.1.4 Configuration of process and workpiece . 15
5.1.5 Wire-wrap process certification . 16
5.1.6 Requirements for new combinations of wire-wrap . 16
5.2 Material selection . 17
5.2.1 Wire . 17
5.2.2 Terminal post . 19
5.3 Wire-wrap operation . 22
5.3.1 Preparation for wire-wrapping . 22
5.3.2 Process and criteria . 22
5.3.3 Number of turns on terminal post . 24
5.3.4 Wire routing. 25
5.3.5 Rework . 25
5.4 Test methods . 26
5.4.1 General . 26
5.4.2 Stripping force . 26
5.4.3 Unwrapping test . 27
2

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EN 16602-70-30:2014 (E)
5.4.4 Connection resistance . 27
5.4.5 Gas-tightness test . 28
5.4.6 Metallography . 28
5.4.7 Records of tests . 29
5.5 Workmanship and acceptance criteria . 29
5.5.1 Visual inspection . 29
5.5.2 Replacement and rework . 30
5.5.3 Performance tests . 31
5.6 Quality assurance . 32
5.6.1 General . 32
5.6.2 Traceability . 32
5.6.3 Data . 33
5.6.4 Nonconformance . 33
5.6.5 Calibration . 35
5.6.6 Workmanship standards. 35
5.6.7 Operator and inspector training and certification . 35
5.6.8 Inspections . 36
5.7 Document requirements. 37
Annex A (informative) Procedure for wire-rapping . 38
Bibliography . 46

Figures
Figure 1-1: Single wire-wrapped connection to square terminal and reference corner . 7
Figure 5-1: Minimum wrapping length on terminal post for each wire gauge . 21
Figure 5-2: Terminal post dimensions over minimum wrapping length for each terminal
size . 21
Figure 5-3: Position and regularity of wrap connection . 24
Figure 5-4: Wire-wrap rejection criteria which require reworking of the connection . 31
Figure 5-5: Guide to quality assurance during wire wrapping. 34
Figure 5-6: Guide to quality assurance during wire wrapping. 34
Figure A-1 : Examples of approved wire-wrapping tools . 39
Figure A-2 : Wire-wrap connection process . 40
Figure A-3 : Hand unwrapping tools . 41
Figure A-4 : Example of a daily process control sheet for test samples . 43
Figure A-5 : Stripping force test fixture . 44
Figure A-6 : Connection resistance test . 44
Figure A-7 : Typical cross-section of wire-wrap (×64) . 45
3

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EN 16602-70-30:2014 (E)
Figure A-8 : Gas-tightness test result . 45

Tables
Table 5-1: Wire size to terminal post combinations . 22
Table 5-2: Minimum number of wire turns on terminal post . 25
Table 5-3: Minimum stripping force . 27
Table 5-4: Test current for connection resistance . 28

4

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Foreword
This document (EN 16602-70-30:2014) has been prepared by Technical
Committee CEN/CLC/TC 5 “Space”, the secretariat of which is held by DIN.
This standard (EN 16602-70-30:2014) originates from ECSS-Q-ST-70-30C.
This European Standard shall be given the status of a national standard, either
by publication of an identical text or by endorsement, at the latest by April 2015,
and conflicting national standards shall be withdrawn at the latest by April
2015.
Attention is drawn to the possibility that some of the elements of this document
may be the subject of patent rights. CEN [and/or CENELEC] shall not be held
responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the
European Commission and the European Free Trade Association.
This document has been developed to cover specifically space systems and has
therefore precedence over any EN covering the same scope but with a wider
domain of applicability (e.g. : aerospace).
According to the CEN-CENELEC Internal Regulations, the national standards
organizations of the following countries are bound to implement this European
Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
5

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EN 16602-70-30:2014 (E)
1
Scope
This Standard specifies requirements for preparing and assembling parts to be
joined by wire wrapping, as well as the selection, calibration, use and
certification of wire wrapping tools.
The covered wire-wrapped connections are illustrated in Figure 1-1.
This type of connection is similar to “Class A preferred” or “modified”
connection detailed in MIL-STD-1130, and NASA NHB 5300.4(3H).
Only previously tested and qualified wire-wrapped connections are covered by
this Standard, which includes four wire sizes from 24 AWG to 30 AWG, and
three terminal post sizes up to 1,78 mm maximum diagonal. A step-by step
procedure is covered in the informative Annex A.
The use of heavier gauge wire and larger terminals is not generally prohibited,
but it is considered unlikely that for such dimensions the method of
wire-wrapping would be chosen as the electrical interconnection technique.
Instead it is assumed that wire larger than 24 AWG will be multi-stranded and
terminated by soldering in conformance with ECSS-Q-ST-70-08, or by crimping
in conformance with ECSS-Q-ST-70-26.
Training and certification requirements for operators and inspectors are defined
in clause 5.6.7 and in ECSS-Q-ST-20.
With effect from the date of approval, this Standard announces the adoption of
the external document on a restricted basis for use in the European Cooperation
for Space Standardization (ECSS) system.
This standard may be tailored for the specific characteristic and constraints of a
space project in conformance with ECSS-S-ST-00.

6

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Terminal post
End tail
Uninsulated wire turns
Insulated wire
Reference corner
(and at 1 below)

1
1
3 4
2
2
3
Shows either 3 or 4 corners of contact of insulation minimum ¾ turn of insulated
wire

Figure 1-1: Single wire-wrapped connection to square terminal and reference
corner
7

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EN 16602-70-30:2014 (E)
2
Normative references
The following normative documents contain provisions which, through
reference in this text, constitute provisions of this ECSS Standard. For dated
references, subsequent amendments to, or revisions of any of these publications
do not apply. However, parties to agreements based on this ECSS Standard are
encouraged to investigate the possibility of applying the most recent editions of
the normative documents indicated below. For undated references the latest
edition of the publication referred to applies.

EN reference Reference in text Title
EN 16601-00-01 ECSS-S-ST-00-01 ECSS system – Glossary of terms
EN 16602-20 ECSS-Q-ST-20 Space product assurance – Quality assurance
EN 16602-70-02 ECSS-Q-ST-70-02 Space product assurance – Thermal vacuum
outgassing test for the screening of space materials
EN 16602-70-38 ECSS-Q-ST-70-38 Space product assurance – High-reliability soldering
for surface-mount and mixed technology
ESSCC Generic Solid wires, electrical 350V, for wire wrapping
specification 3903
8

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3
Terms, definitions and abbreviated terms
3.1 Terms defined in other standards
For the purpose of this Standard, the terms and definitions from
ECSS-S-ST-00-01 and ECSS-Q-ST-70-38 apply.
In particular from ECSS-Q-ST-70-38 the following term:
process identification document (PID)
NOTE The content of the PID is specified in
ECSS-Q-ST-70-38.
3.2 Terms specific to the present standard
3.2.1 a turn of wire
a wrap consisting of one complete single helical ring of wire wrapped 360
degrees around the terminal post, touching all four corners of the post.
NOTE For the purpose of counting turns, the number of
times the wrapped wire passes and intercepts the
reference edge of the terminal post after the first
intercept of uninsulated wire and terminal post,
constitutes the number of turns of uninsulated
wire in the connection.
3.2.2 end tail
end of the last turn of wire on the terminal post which can extend in a
tangential direction instead of resting against the post
3.2.3 gas-tight area
contact area between the terminal post and wire which excludes gas fumes
3.2.4 reference corner
corner of the terminal post at which the first turn of uninsulated wire contacts,
and from which the number of turns of the wrapped wire are counted.
3.2.5 terminal post
post of square or rectangular section onto which the interconnection wire is
wrapped.
9

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SIST EN 16602-70-30:2015
EN 16602-70-30:2014 (E)
3.2.6 wire-wrapped connection
connection consisting of a helix of continuous, solid, non-insulated wire tightly
wrapped around the terminal post to produce a mechanically and electrically
stable connection.
NOTE 1 The number of turns required will depend on the
gauge of wire used.
NOTE 2 All completed wraps have an additional minimum
of 3/4 turn of the insulated wire that is in contact
with at least three corners of the terminal post (see
Figure 1-1).
3.3 Abbreviated terms
For the purpose of this Standard, the abbreviated terms from ECSS-S-ST-00-01
and the following apply:

Abbreviation Meaning
AWG American wire gauge
ETFE ethylene-tetrafluorethylene (Tefzel)
NCR nonconformance report
PFA perfluoroalkoxy
PID process identification document
PTFE polytetrafluorethylene
PVDF polyvinylidene fluoride (Kynar)
QA quality assurance
RFA request for approval
RH relative humidity

10

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EN 16602-70-30:2014 (E)
4
Principles
The production of wire-wrapped connections is a relatively simple yet precision
method of fusion. Its use for high reliability space conditions affords high skills
of operators and inspectors as well as tooling and environmental controls to
produce continued high level quality. The following principles are laid down in
this Standard:
• Each tool is certified for each wire to post configuration; regular
calibration is mandatory.
• All material, including wire and post, requires approval and rigorous
inspection.
• A well-defined and documented process control document (PID) to
ensure consistency of production over extended periods.
• Operators and inspectors need experience and regular training and
certification.
• Frequent inline inspection and testing of wire-wraps validate continued
quality levels for the intended high reliability application.
Formal Quality Assurance and documentation will substantiate the achieved
level of compliance to the requirements within this Standard.
It is important to perform the work taking into account health and safety
regulations and in particular the national standards on this subject.

11

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5
Requirements
5.1 Preparatory conditions
5.1.1 Hazards, health and safety precautions
a. Components, tools and controls shall be so located that personnel are not
exposed to hazards such as electric shock, cutting edges, sharp points or
toxic atmospheres.
b. Pneumatic air-powered wire-wrapping tools shall be connected to a
regulated, lubricated and filtered air supply, and disconnected when not
in use.
5.1.2 Facilities
5.1.2.1 Facility cleanliness
a. The supplier shall provide for a work environment in conformance with
the following:
NOTE Those requirements are in general met by using
cleanrooms. It is not, however, mandatory to
use a cleanroom.
1. The areas in which wire-wrapping is carried out are maintained in
a neat orderly fashion, with no loose material that can cause
contamination of the wire-wrapped connection.
NOTE For example: Dirt, dust, oils or clipped wires.
2. Furniture is kept to a minimum in the work areas and be arranged
to allow easy and thorough cleaning of the floor.
3. Working surfaces are covered with an easily cleaned hard top, or
have a replaceable surface of clean, non-corrosive silicone-free
paper.
4. Tools used in the wire-wrapping operation are clean.
NOTE For example: Excess lubricant is removed
before wire-wrapping starts.
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5.1.2.2 Environmental conditions
a. The following environmental conditions at the wire-wrapping
workstations shall be established:
1. controlled environment which limits entry of contamination;
2. continuously controlled temperature and humidity as follows:
(a) room temperature: (22 ± 3) °C;
(b) relative humidity: (55 ± 10) %.
3. no exposure to draughts;
4. supply of fresh air through a filtering system to establish a positive
pressure difference to adjacent rooms; the exhaust air is restricted
to avoid turbulences.
5.1.2.3 Lighting requirements
a. Adequate illumination conditions of the wire-wrapping workstations
shall be implemented as follows:
1. light intensity with a minimum of 1080 lux on the work surface.
2. at least 90 % of the work area are shadowless and without severe
reflections.
5.1.3 Tools and equipment
5.1.3.1 Cutting tool
a. The selected cutting tool shall cut the conductor wire without causing
flattening of the wire.
b. Any tool not conforming with requirement 5.1.3.1a shall be removed
from the work area.
5.1.3.2 Insulation strippers
a. To avoid damage to the conductor, stripping devices, in particular
thermal and precision cutting devices, manual or automatic power-
driven shall
1. provide protection of the conductor wire;
2. avoid wire stretching by use of mechanical strippers;
3. avoid that the conductor is twisted, ringed, nicked, cut or scored
by the stripping operation.
b. Any tool not conforming with requirement 5.1.3.2a shall be removed
from the work area.
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5.1.3.3 Wire-wrapping tools
a. Wrapping tools together with specific rotary bit and stationary sleeve
shall be
1. assigned to each wire gauge and terminal combination in use,
2. marked to show the size, for which it is calibrated.
b. The following power-driven wire-wrapping tools shall be used:
1. electrical tool with mains supply,
2. pneumatic tool, supplied with regulated, lubricated and filtered
air.
NOTE Figure A-1 shows examples of power-driven
wire-wrapping tools.
c. The power-driven wire-wrapping tools should be fitted with a “back-
force” device to prevent overwrapping defect.
d. Hand-powered or battery-powered wrapping tools shall not be used.
NOTE Refer to the tool manufacturer for selection of bit
and sleeve for each wire/terminal post diagonal
combination.
e. The tool and associated accessories shall be checked for cleanliness and
general satisfactory condition under up to ×10 magnification as follows:
1. The extremity of the bit is perfectly clean and smooth without
blockages or faults.
2. The sleeve does not have any sharp blockage in its neck, and
manual check ensures that the bit runs perfectly in the sleeve,
without any hard or rough points of contact.
f. The wire-wrapping tool shall not nick, ring, gouge, or scrape conductors,
or damage the terminal post in any way during its operation.
g. Any tool not conforming with the requirements 5.1.3.3a to 5.1.3.3f shall
be removed from the work-station for repair or replacement.
5.1.3.4 Unwrapping tools
a. The supplier shall provide an unwrapping tool compatible with the
terminal post diagonal which does not nick, ring, gouge, scrape or
damage the terminal post in any way.
NOTE 1 Figure A-3 shows examples of unwrapping tools.
NOTE 2 Wrapped connections can be detached from their
terminal posts, when necessary, by means of
special unwrapping tools.
NOTE 3 Manual unwrapping tools are preferred. They are
short tubular tools having an external spiral
groove and handle.
NOTE 4 A “left-hand” unwrapping tool is required to
unwrap a “right-hand” wrap connection
(clockwise wire rotation from base to top of
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SIST EN 16602-70-30:2015
EN 16602-70-30:2014 (E)
terminal), or vice versa for a “left-hand” wrap
connection.
b. Damaged tools shall be removed from the work-station for repair or
replacement.
5.1.3.5 Test monitoring equipment
a. Equipment for performance testing shall have the following
characteristics:
1. Connection 0 A - 10 A ammeter with current source
resistance
0 mV - 20 mV voltmeter
2. Stripping force Tensile testing machine
0 N - 100 N, accurate to ± 0,2 N
3. Visual inspection Binocular microscope, magnification × 7
minimum, with suitable light source
4. Microsectioning: Metallurgical microscope, magnification up
to × 400.
b. The equipment shall be capable of monitoring in the following range of
environmental conditions:
1. Temperature 15° C to 30° C, accurate to ± 1 °C
2. Humidity
RH 40 % to 70 %, accurate to ± 1 % RH
5.1.4 Configuration of process and workpiece
a. Materials, tools and techniques, which are planned to be used shall be
reviewed with respect to design needs, to ensure conformance to
customer requirements and as a means of identifying any pending
process qualification.
b. The review shall cover each separate manufacturing step including the
dimensions and metallurgical properties of the terminal post and wire.
NOTE Aim is that materials are proven to be acceptable
for the manufacture of wire-wrapped connections.
c. The choice of functional tools, particularly the type of power-driven
wire-wrapping tool and associated rotary wrapping bit and stationary
sleeve shall be demonstrated to be adequate to the wrapping process.
NOTE The quality of a wrapped connection depends
largely on the maintenance and adjusting of the
cutting, stripping and wrapping tools.
d. The supplier shall generate a dedicated process identification document
(PID) in conformance with the requirements in ECSS-Q-ST-70-38, listing
all used tools, material and the adjustment of the tools.
e. Work shall be managed and organized such that tool bits and sleeves
cannot be interchanged.
f. During handling and transportation, wrapped joints and their wires shall
not suffer from any mechanical or environmental constraint, likely to
cause deterioration.
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5.1.5 Wire-wrap process certification
5.1.5.1 Initial certification of each wire-wrap combination
a. The capability of the wire-wrap tool shall be established to produce
acceptable wire-wrap connections for each combination of tool with
correct bit and sleeve, wire gauge and terminal post.
b. 30 sample wrap connections shall be prepared with a calibrated tool.
c. The certification test sequence shall be as follows:
1. Samples 1 to 30 Workmanship (see clause 5.5.1)
2. Samples 1 to 30 Connection resistance (see clause 5.4.4)
3. Samples 1 to 10 Stripping force (see clause 5.4.2)
4. Samples 11 to 20 Unwrapping test (see clause 5.4.3)
5. Samples 21 to 26 Gas-tightness test (see clause 5.4.5)
6. Samples 27 to 30 Metallography (see clause 5.4.6)
NOTE The successful completion of all above tests will
authorize spacecraft wire wrapping to commence
for the wrap combination.
5.1.5.2 Re-certification of each wire-wrap combination
a. Re-certification shall be carried out after the following occurrences:
1. When production wraps fail to conform with the requirements of
the daily process-control tests specified in clause 5.6.8.3.
2. At every 10 000 wire-wrap connections in a continuous
programme.
3. If production is interrupted for a period in excess of 12 months.
NOTE This is supposed to ensure reliability of the
joint, as the wire and terminals may degrade
during storage.
b. The re-certification test sequence shall be a repeat of the above clause
5.1.5.1, 30 sample wrap connections being prepared with a calibrated
tool.
5.1.6 Requirements for new combinations of wire-
wrap
5.1.6.1 General
a. Verification tests shall be conducted to establish confidence in the
reliability of wire-wrap combinations not detailed in Table 5-1.
b. The combination shall be considered verified following successful
completion of process certification tests in conformance with
requirements of clause 5.1.5 on 30 sample wraps before, and a further 30
16

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SIST EN 16602-70-30:2015
EN 16602-70-30:2014 (E)
sample wraps after temperature cycling and vibration testing detailed
below.
5.1.6.2 Temperature cycling
a. The test samples shall undergo 200 temperature cycles i
...

SLOVENSKI STANDARD
kSIST FprEN 16602-70-30:2014
01-februar-2014
åLþQLPRYLMDQMHP=DJRWDYOMDQMHYDUQLKSURL]YRGRYYYHVROMVNLWHKQLNL6SDMDQMH]
NRQWDNWRYYLVRNR]DQHVOMLYLKHOHNWULþQLKNRQHNWRUMHY
Space product assurance - Wire wrapping of high-reliability electrical connections
Raumfahrtproduktsicherung - Umhüllung von Kabeln für hochzuverlässige elektrische
Verbindungen
Assurance produit des projets spatiaux - Enveloppe de fils pour connexion électrique à
fiabilité élevée
Ta slovenski standard je istoveten z: FprEN 16602-70-30
ICS:
49.060 /HWDOVNDLQYHVROMVND Aerospace electric
HOHNWULþQDRSUHPDLQVLVWHPL equipment and systems
49.140 Vesoljski sistemi in operacije Space systems and
operations
kSIST FprEN 16602-70-30:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST FprEN 16602-70-30:2014

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kSIST FprEN 16602-70-30:2014


EUROPEAN STANDARD
FINAL DRAFT
FprEN 16602-70-30
NORME EUROPÉENNE

EUROPÄISCHE NORM

October 2013
ICS 49.140

English version
Space product assurance - Wire wrapping of high-reliability
electrical connections
Assurance produit des projets spatiaux - Enveloppe de fils Raumfahrtproduktsicherung - Umhüllung von Kabeln für
pour connexion électrique à fiabilité élevée hochzuverlässige elektrische Verbindungen
This draft European Standard is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical
Committee CEN/CLC/TC 5.

If this draft becomes a European Standard, CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal
Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN and CENELEC in three official versions (English, French, German). A version in any
other language made by translation under the responsibility of a CEN and CENELEC member into its own language and notified to the
CEN-CENELEC Management Centre has the same status as the official versions.

CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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.



CEN-CENELEC Management Centre:
Avenue Marnix 17, B-1000 Brussels
© 2013 CEN/CENELEC All rights of exploitation in any form and by any means reserved Ref. No. FprEN 16602-70-30:2013 E
worldwide for CEN national Members and for CENELEC
Members.

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FprEN 16602-70-30:2013 (E)
Table of contents
Foreword . 5
1 Scope . 6
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 9
3.1 Terms defined in other standards . 9
3.2 Terms specific to the present standard . 9
3.3 Abbreviated terms. 10
4 Principles . 11
5 Requirements . 12
5.1 Preparatory conditions . 12
5.1.1 Hazards, health and safety precautions . 12
5.1.2 Facilities . 12
5.1.3 Tools and equipment . 13
5.1.4 Configuration of process and workpiece . 15
5.1.5 Wire-wrap process certification . 16
5.1.6 Requirements for new combinations of wire-wrap . 16
5.2 Material selection . 17
5.2.1 Wire . 17
5.2.2 Terminal post . 19
5.3 Wire-wrap operation . 22
5.3.1 Preparation for wire-wrapping . 22
5.3.2 Process and criteria . 22
5.3.3 Number of turns on terminal post . 24
5.3.4 Wire routing. 25
5.3.5 Rework . 25
5.4 Test methods . 26
5.4.1 General . 26
5.4.2 Stripping force . 26
5.4.3 Unwrapping test . 27
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5.4.4 Connection resistance . 27
5.4.5 Gas-tightness test . 28
5.4.6 Metallography . 28
5.4.7 Records of tests . 29
5.5 Workmanship and acceptance criteria . 29
5.5.1 Visual inspection . 29
5.5.2 Replacement and rework . 30
5.5.3 Performance tests . 31
5.6 Quality assurance . 32
5.6.1 General . 32
5.6.2 Traceability . 32
5.6.3 Data . 33
5.6.4 Nonconformance . 33
5.6.5 Calibration . 35
5.6.6 Workmanship standards. 35
5.6.7 Operator and inspector training and certification . 35
5.6.8 Inspections . 36
5.7 Document requirements. 37
Annex A (informative) Procedure for wire-rapping . 38
Bibliography . 46

Figures
Figure 1-1: Single wire-wrapped connection to square terminal and reference corner . 7
Figure 5-1: Minimum wrapping length on terminal post for each wire gauge . 21
Figure 5-2: Terminal post dimensions over minimum wrapping length for each terminal
size . 21
Figure 5-3: Position and regularity of wrap connection . 24
Figure 5-4: Wire-wrap rejection criteria which require reworking of the connection . 31
Figure 5-5: Guide to quality assurance during wire wrapping. 34
Figure 5-6: Guide to quality assurance during wire wrapping. 34
Figure A-1 : Examples of approved wire-wrapping tools . 39
Figure A-2 : Wire-wrap connection process . 40
Figure A-3 : Hand unwrapping tools . 41
Figure A-4 : Example of a daily process control sheet for test samples . 43
Figure A-5 : Stripping force test fixture . 44
Figure A-6 : Connection resistance test . 44
Figure A-7 : Typical cross-section of wire-wrap (×64) . 45
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Figure A-8 : Gas-tightness test result . 45

Tables
Table 5-1: Wire size to terminal post combinations . 22
Table 5-2: Minimum number of wire turns on terminal post . 25
Table 5-3: Minimum stripping force . 27
Table 5-4: Test current for connection resistance . 28


4

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Foreword
This document (FprEN 16602-70-30:2013) has been prepared by Technical
Committee CEN/CLC/TC 5 “Space”, the secretariat of which is held by DIN
(Germany).
This document (FprEN 16602-70-30:2013) originates from ECSS-Q-ST-70-30C.
This document is currently submitted to the Unique Acceptance Procedure.
This document has been developed to cover specifically space systems and will
the-refore have precedence over any EN covering the same scope but with a
wider do-main of applicability (e.g. : aerospace).
5

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1
Scope
This Standard specifies requirements for preparing and assembling parts to be
joined by wire wrapping, as well as the selection, calibration, use and
certification of wire wrapping tools.
The covered wire-wrapped connections are illustrated in Figure 1-1.
This type of connection is similar to “Class A preferred” or “modified”
connection detailed in MIL-STD-1130, and NASA NHB 5300.4(3H).
Only previously tested and qualified wire-wrapped connections are covered by
this Standard, which includes four wire sizes from 24 AWG to 30 AWG, and
three terminal post sizes up to 1,78 mm maximum diagonal. A step-by step
procedure is covered in the informative Annex A.
The use of heavier gauge wire and larger terminals is not generally prohibited,
but it is considered unlikely that for such dimensions the method of
wire-wrapping would be chosen as the electrical interconnection technique.
Instead it is assumed that wire larger than 24 AWG will be multi-stranded and
terminated by soldering in conformance with ECSS-Q-ST-70-08, or by crimping
in conformance with ECSS-Q-ST-70-26.
Training and certification requirements for operators and inspectors are defined
in clause 5.6.7 and in ECSS-Q-ST-20.
With effect from the date of approval, this Standard announces the adoption of
the external document on a restricted basis for use in the European Cooperation
for Space Standardization (ECSS) system.
This standard may be tailored for the specific characteristic and constraints of a
space project in conformance with ECSS-S-ST-00.

6

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Terminal post
End tail
Uninsulated wire turns
Insulated wire
Reference corner
(and at 1 below)

1
1
3 4
2
2
3
Shows either 3 or 4 corners of contact of insulation minimum ¾ turn of insulated
wire

Figure 1-1: Single wire-wrapped connection to square terminal and reference
corner
7

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2
Normative references
The following normative documents contain provisions which, through
reference in this text, constitute provisions of this ECSS Standard. For dated
references, subsequent amendments to, or revisions of any of these publications
do not apply. However, parties to agreements based on this ECSS Standard are
encouraged to investigate the possibility of applying the most recent editions of
the normative documents indicated below. For undated references the latest
edition of the publication referred to applies.

EN reference Reference in text Title
EN 16601-00-01 ECSS-S-ST-00-01 ECSS system – Glossary of terms
EN 16602-20 ECSS-Q-ST-20 Space product assurance – Quality assurance
EN 16602-70-02 ECSS-Q-ST-70-02 Space product assurance – Thermal vacuum
outgassing test for the screening of space materials
EN 16602-70-38 ECSS-Q-ST-70-38 Space product assurance – High-reliability soldering
for surface-mount and mixed technology
ESSCC Generic Solid wires, electrical 350V, for wire wrapping
specification 3903
8

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3
Terms, definitions and abbreviated terms
3.1 Terms defined in other standards
For the purpose of this Standard, the terms and definitions from
ECSS-S-ST-00-01 and ECSS-Q-ST-70-38 apply.
In particular from ECSS-Q-ST-70-38 the following term:
process identification document (PID)
NOTE The content of the PID is specified in
ECSS-Q-ST-70-38.
3.2 Terms specific to the present standard
3.2.1 a turn of wire
a wrap consisting of one complete single helical ring of wire wrapped 360
degrees around the terminal post, touching all four corners of the post.
NOTE For the purpose of counting turns, the number of
times the wrapped wire passes and intercepts the
reference edge of the terminal post after the first
intercept of uninsulated wire and terminal post,
constitutes the number of turns of uninsulated
wire in the connection.
3.2.2 end tail
end of the last turn of wire on the terminal post which can extend in a
tangential direction instead of resting against the post
3.2.3 gas-tight area
contact area between the terminal post and wire which excludes gas fumes
3.2.4 reference corner
corner of the terminal post at which the first turn of uninsulated wire contacts,
and from which the number of turns of the wrapped wire are counted.
3.2.5 terminal post
post of square or rectangular section onto which the interconnection wire is
wrapped.
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3.2.6 wire-wrapped connection
connection consisting of a helix of continuous, solid, non-insulated wire tightly
wrapped around the terminal post to produce a mechanically and electrically
stable connection.
NOTE 1 The number of turns required will depend on the
gauge of wire used.
NOTE 2 All completed wraps have an additional minimum
of 3/4 turn of the insulated wire that is in contact
with at least three corners of the terminal post (see
Figure 1-1).
3.3 Abbreviated terms
For the purpose of this Standard, the abbreviated terms from ECSS-S-ST-00-01
and the following apply:

Abbreviation Meaning
AWG American wire gauge
ETFE ethylene-tetrafluorethylene (Tefzel)
NCR nonconformance report
PFA perfluoroalkoxy
PID process identification document
PTFE polytetrafluorethylene
PVDF polyvinylidene fluoride (Kynar)
QA quality assurance
RFA request for approval
RH relative humidity

10

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4
Principles
The production of wire-wrapped connections is a relatively simple yet precision
method of fusion. Its use for high reliability space conditions affords high skills
of operators and inspectors as well as tooling and environmental controls to
produce continued high level quality. The following principles are laid down in
this Standard:
• Each tool is certified for each wire to post configuration; regular
calibration is mandatory.
• All material, including wire and post, requires approval and rigorous
inspection.
• A well-defined and documented process control document (PID) to
ensure consistency of production over extended periods.
• Operators and inspectors need experience and regular training and
certification.
• Frequent inline inspection and testing of wire-wraps validate continued
quality levels for the intended high reliability application.
Formal Quality Assurance and documentation will substantiate the achieved
level of compliance to the requirements within this Standard.
It is important to perform the work taking into account health and safety
regulations and in particular the national standards on this subject.

11

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5
Requirements
5.1 Preparatory conditions
5.1.1 Hazards, health and safety precautions
a. Components, tools and controls shall be so located that personnel are not
exposed to hazards such as electric shock, cutting edges, sharp points or
toxic atmospheres.
b. Pneumatic air-powered wire-wrapping tools shall be connected to a
regulated, lubricated and filtered air supply, and disconnected when not
in use.
5.1.2 Facilities
5.1.2.1 Facility cleanliness
a. The supplier shall provide for a work environment in conformance with
the following:
NOTE Those requirements are in general met by using
cleanrooms. It is not, however, mandatory to
use a cleanroom.
1. The areas in which wire-wrapping is carried out are maintained in
a neat orderly fashion, with no loose material that can cause
contamination of the wire-wrapped connection.
NOTE For example: Dirt, dust, oils or clipped wires.
2. Furniture is kept to a minimum in the work areas and be arranged
to allow easy and thorough cleaning of the floor.
3. Working surfaces are covered with an easily cleaned hard top, or
have a replaceable surface of clean, non-corrosive silicone-free
paper.
4. Tools used in the wire-wrapping operation are clean.
NOTE For example: Excess lubricant is removed
before wire-wrapping starts.
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5.1.2.2 Environmental conditions
a. The following environmental conditions at the wire-wrapping
workstations shall be established:
1. controlled environment which limits entry of contamination;
2. continuously controlled temperature and humidity as follows:
(a) room temperature: (22 ± 3) °C;
(b) relative humidity: (55 ± 10) %.
3. no exposure to draughts;
4. supply of fresh air through a filtering system to establish a positive
pressure difference to adjacent rooms; the exhaust air is restricted
to avoid turbulences.
5.1.2.3 Lighting requirements
a. Adequate illumination conditions of the wire-wrapping workstations
shall be implemented as follows:
1. light intensity with a minimum of 1080 lux on the work surface.
2. at least 90 % of the work area are shadowless and without severe
reflections.
5.1.3 Tools and equipment
5.1.3.1 Cutting tool
a. The selected cutting tool shall cut the conductor wire without causing
flattening of the wire.
b. Any tool not conforming with requirement 5.1.3.1a shall be removed
from the work area.
5.1.3.2 Insulation strippers
a. To avoid damage to the conductor, stripping devices, in particular
thermal and precision cutting devices, manual or automatic power-
driven shall
1. provide protection of the conductor wire;
2. avoid wire stretching by use of mechanical strippers;
3. avoid that the conductor is twisted, ringed, nicked, cut or scored
by the stripping operation.
b. Any tool not conforming with requirement 5.1.3.2a shall be removed
from the work area.
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5.1.3.3 Wire-wrapping tools
a. Wrapping tools together with specific rotary bit and stationary sleeve
shall be
1. assigned to each wire gauge and terminal combination in use,
2. marked to show the size, for which it is calibrated.
b. The following power-driven wire-wrapping tools shall be used:
1. electrical tool with mains supply,
2. pneumatic tool, supplied with regulated, lubricated and filtered
air.
NOTE Figure A-1 shows examples of power-driven
wire-wrapping tools.
c. The power-driven wire-wrapping tools should be fitted with a “back-
force” device to prevent overwrapping defect.
d. Hand-powered or battery-powered wrapping tools shall not be used.
NOTE Refer to the tool manufacturer for selection of bit
and sleeve for each wire/terminal post diagonal
combination.
e. The tool and associated accessories shall be checked for cleanliness and
general satisfactory condition under up to ×10 magnification as follows:
1. The extremity of the bit is perfectly clean and smooth without
blockages or faults.
2. The sleeve does not have any sharp blockage in its neck, and
manual check ensures that the bit runs perfectly in the sleeve,
without any hard or rough points of contact.
f. The wire-wrapping tool shall not nick, ring, gouge, or scrape conductors,
or damage the terminal post in any way during its operation.
g. Any tool not conforming with the requirements 5.1.3.3a to 5.1.3.3f shall
be removed from the work-station for repair or replacement.
5.1.3.4 Unwrapping tools
a. The supplier shall provide an unwrapping tool compatible with the
terminal post diagonal which does not nick, ring, gouge, scrape or
damage the terminal post in any way.
NOTE 1 Figure A-3 shows examples of unwrapping tools.
NOTE 2 Wrapped connections can be detached from their
terminal posts, when necessary, by means of
special unwrapping tools.
NOTE 3 Manual unwrapping tools are preferred. They are
short tubular tools having an external spiral
groove and handle.
NOTE 4 A “left-hand” unwrapping tool is required to
unwrap a “right-hand” wrap connection
(clockwise wire rotation from base to top of
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terminal), or vice versa for a “left-hand” wrap
connection.
b. Damaged tools shall be removed from the work-station for repair or
replacement.
5.1.3.5 Test monitoring equipment
a. Equipment for performance testing shall have the following
characteristics:
1. Connection 0 A - 10 A ammeter with current source
resistance
0 mV - 20 mV voltmeter
2. Stripping force Tensile testing machine
0 N - 100 N, accurate to ± 0,2 N
3. Visual inspection Binocular microscope, magnification × 7
minimum, with suitable light source
4. Microsectioning: Metallurgical microscope, magnification up
to × 400.
b. The equipment shall be capable of monitoring in the following range of
environmental conditions:
1. Temperature 15° C to 30° C, accurate to ± 1 °C
2. Humidity
RH 40 % to 70 %, accurate to ± 1 % RH
5.1.4 Configuration of process and workpiece
a. Materials, tools and techniques, which are planned to be used shall be
reviewed with respect to design needs, to ensure conformance to
customer requirements and as a means of identifying any pending
process qualification.
b. The review shall cover each separate manufacturing step including the
dimensions and metallurgical properties of the terminal post and wire.
NOTE Aim is that materials are proven to be acceptable
for the manufacture of wire-wrapped connections.
c. The choice of functional tools, particularly the type of power-driven
wire-wrapping tool and associated rotary wrapping bit and stationary
sleeve shall be demonstrated to be adequate to the wrapping process.
NOTE The quality of a wrapped connection depends
largely on the maintenance and adjusting of the
cutting, stripping and wrapping tools.
d. The supplier shall generate a dedicated process identification document
(PID) in conformance with the requirements in ECSS-Q-ST-70-38, listing
all used tools, material and the adjustment of the tools.
e. Work shall be managed and organized such that tool bits and sleeves
cannot be interchanged.
f. During handling and transportation, wrapped joints and their wires shall
not suffer from any mechanical or environmental constraint, likely to
cause deterioration.
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5.1.5 Wire-wrap process certification
5.1.5.1 Initial certification of each wire-wrap combination
a. The capability of the wire-wrap tool shall be established to produce
acceptable wire-wrap connections for each combination of tool with
correct bit and sleeve, wire gauge and terminal post.
b. 30 sample wrap connections shall be prepared with a calibrated tool.
c. The certification test sequence shall be as follows:
1. Samples 1 to 30 Workmanship (see clause 5.5.1)
2. Samples 1 to 30 Connection resistance (see clause 5.4.4)
3. Samples 1 to 10 Stripping force (see clause 5.4.2)
4. Samples 11 to 20 Unwrapping test (see clause 5.4.3)
5. Samples 21 to 26 Gas-tightness test (see clause 5.4.5)
6. Samples 27 to 30 Metallography (see clause 5.4.6)
NOTE The successful completion of all above tests will
authorize spacecraft wire wrapping to commence
for the wrap combination.
5.1.5.2 Re-certification of each wire-wrap combination
a. Re-certification shall be carried out after the following occurrences:
1. When production wraps fail to conform with the requirements of
the daily process-control tests specified in clause 5.6.8.3.
2. At every 10 000 wire-wrap connections in a continuous
programme.
3. If production is interrupted for a period in excess of 12 months.
NOTE This is supposed to ensure reliability of the
joint, as the wire and terminals may degrade
during storage.
b. The re-certification test sequence shall be a repeat of the above clause
5.1.5.1, 30 sample wrap connections being prepared with a calibrated
tool.
5.1.6 Requirements for new combinations of wire-
wrap
5.1.6.1 General
a. Verification tests shall be conducted to establish confidence in the
reliability of wire-wrap combinations not detailed in Table 5-1.
b. The combination shall be considered verified following successful
completion of process certification tests in conformance with
requirements of clause 5.1.5 on 30 sample wraps before, and a further 30
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sample wraps after temperature cycling and vibration testing detailed
below.
5.1.6.2 Temperature cycling
a. The test samples shall undergo 200 temperature cycles in a chamber from
room temperature to -55 °C, to +100 °C and back to room temperature
(22 ± 3)°C at a rate not exceeding 10 °C per minute.
b. Soak time at each temperature extreme shall be 15 minutes, such that the
duration of each cycle averaging one hour.
NOTE These conditions can be modified to conform with
the particular environmental qualification
conditions for the assembly being verified.
5.1.6.3 Vibration
a. After completion of the temperature cycling, the test samples shall be
subjected to vibration.
...

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