ANSI/EIA-364-21C-2000

Approved: March 10, 2000

EIA
STANDARD
EIA-364-21C

TP-21C

Insulation Resistance Test Procedure

for Electrical Connectors, Sockets, and
Coaxial Contacts

EIA-364-21C
(Revision of EIA-364-21B)

MAY 2000

ELECTRONIC COMPONENTS, ASSEMBLIES & MATERIALS

ASSOCIATION
THE ELECTRONIC COMPONENT SECTOR OF THE ELECTRONIC INDUSTRIES ALLIANCE
 NOTICE

EIA Engineering Standards and Publications are designed to serve the public interest through
eliminating misunderstandings between manufacturers and purchasers, facilitating
interchangeability and improvement of products, and assisting the purchaser in selecting and
obtaining with minimum delay the proper product for his particular need. Existence of such
Standards and Publications shall not in any respect preclude any member or nonmember of
EIA from manufacturing or selling products not conforming to such Standards and
Publications, nor shall the existence of such Standards and Publications preclude their
voluntary use by those other than EIA members, whether the standard is to be used either
domestically or internationally.

Standards and Publications are adopted by EIA in accordance with the American National
Standards Institute (ANSI) patent policy. By such action, EIA does not assume any liability to
any patent owner, nor does it assume any obligation whatever to parties adopting the Standard
or Publication.

This standard is based upon the major technical content of International Electrotechnical
Commission standard 512-2, test 3a, insulation resistance, 1985. It conforms in all essential
respects to this IEC standard.

This Standard does not purport to address all safety problems associated with its use or all
applicable regulatory requirements. It is the responsibility of the user of this Standard to
establish appropriate safety and health practices and to determine the applicability of regulatory
limitations before its use.

(From Standards Proposal Number 4213-A, formulated under the cognizance of the CE-2.0
National Connector Standards Committee.)

Published by

8ELECTRONIC INDUSTRIES ALLIANCE 2000

Technology Strategy & Standards Department
2500 Wilson Boulevard
Arlington, VA 22201

PRICE: Please refer to the current

Catalog of EIA Electronic Industries Alliance Standards and Engineering Publications
or call Global Engineering Documents, USA and Canada (1-800-854-7179)
International (303-397-7956)

All rights reserved

Printed in U.S.A.

中国可靠性网 http://www.kekaoxing.com
 PLEASE!

DON”T VIOLATE
THE
LAW!

This document is copyrighted by the EIA and may not be reproduced without
permission.

Organizations may obtain permission to reproduce a limited number of copies

through entering into a license agreement. For information, contact:

Global Engineering Documents

15 Inverness Way East
Englewood, CO 80112-5704 or call
U.S.A. and Canada 1-800-854-7179, International (303) 397-7956
 CONTENTS

Clause Page

1 Introduction .............................................................................................................. 1

1.1 Scope ........................................................................................................................ 1

1.2 Object ....................................................................................................................... 1

2 Test resources ........................................................................................................... 1

2.1 Equipment ................................................................................................................ 1

3 Test specimen ........................................................................................................... 1

3.1 Description ............................................................................................................... 1

3.2 Preparation ............................................................................................................... 2

4 Test procedure .......................................................................................................... 2

4.1 Measurement ............................................................................................................ 2

4.2 Electrification time ................................................................................................... 2
4.3 Precautions ............................................................................................................... 3
4.4 Final measurements .................................................................................................. 3

5 Details to be specified .............................................................................................. 3

6 Test documentation .................................................................................................. 4

Annex

A Informative ............................................................................................................... A-1

中国可靠性网 http://www.kekaoxing.com
(This page left blank)

ii
 EIA-364-21C
Page 1

TEST PROCEDURE No. 21C

INSULATION RESISTANCE TEST PROCEDURE

FOR
ELECTRICAL CONNECTORS, SOCKETS, AND COAXIAL CONTACTS

(From EIA Standards Proposal No. 4213-A, formulated under the cognizance EIA CE-2.0
Committee on National Connector Standards, and previously published in EIA-364-21B.)

1 Introduction

1.1 Scope

This standard applies to electrical connectors, sockets and coaxial contacts.

1.2 Object

The object of this test procedure is to detail a standard method to assess insulation resistance.

2 Test resources

2.1 Test equipment

Insulation resistance measurements shall be made on an apparatus suitable for the characteristics
of the component to be measured, such as a megohm bridge, megohm-meter, insulation
resistance test set, or other suitable apparatus. The voltage source should be capable of supplying
a constant 500 Vdc ± 10%. The equipment shall have an accuracy of ± 5% of the finite value of
the full-scale readings for the range being used. The lowest range of the test equipment read-out
device that is compatible with the results being obtained shall be used so that the minimum
equipment tolerance error will be introduced into the test results.

3 Test specimen

3.1 Description

A test specimen shall consist of a plug, a receptacle, a mated plug and receptacle, a coaxial pin
contact, a coaxial socket contact, or a mated coaxial pin and socket contact.

中国可靠性网 http://www.kekaoxing.com
EIA-364-21C
Page 2

3.2 Preparation

3.2.1 Specimens shall be prepared as they would be for normal applications. Specimens to be
tested shall be free from foreign matter that can affect their operation. When special preparation
or conditions such as special test fixtures, reconnections, grounding, isolation, low atmospheric
pressure, humidity, or immersion in water are required, they shall be specified in the referencing
document.

3.2.2 Unless otherwise specified, test specimens shall be tested in the as-received state. If test
leads are soldered to the terminations, the solder joints and surrounding areas may be cleaned. If
cleaning is specified, the assembly shall be cleaned with a suitable solvent, dipping in distilled
water while still moist with solvent, and conditioned in an air circulating oven at 35 °C ± 5 °C
for 2 hours. When removed from the oven, parts shall be cooled in ambient conditions for a
minimum of 30 minutes prior to the test.

4 Test procedure

4.1 Measurement

Insulation resistance shall be measured separately between the closest adjacent contacts; and
between connector shell or mounting plate and the closest adjacent contact, or both. Unless
otherwise specified in a detail specification, a minimum of six measurements (3 adjacent contacts
and/or 3 contacts-to-shell and/or 3 contacts-to-base plate) or 10% of the total number of contacts
(whichever is greater) shall be made for each case. The same contact locations for a given
connector shall be used each time the insulation resistance test is performed. Unless otherwise
specified, test voltage applied shall be 500 Vdc ± 10%. Insulation resistance measurements for
coaxial contacts shall be made between the inner and outer contacts, as specified in the
referencing document.

4.2 Electrification time

When electrification time is a factor, or when variable data are required, the insulation
measurements shall be made immediately after a two-minute period of uninterrupted test voltage
application, unless otherwise specified. However, if the instrument reading indicates that an
insulation resistance meets the specified limit, and is steady or increasing, the test may be
terminated before the end of the specified period. When more than one measurement is
specified, subsequent measurements of insulation resistance shall be made using the same
polarity as the initial measurements. The minimum value of insulation resistance obtained shall
be greater than the minimum value specified in the requirements for the specimens being tested.
 EIA-364-21C
Page 3

4.3 Precautions

Suitable precautions must be taken to protect personnel and apparatus from the relatively high
potentials used in performing the test. Care shall be taken to prevent a direct short circuit of the
testing apparatus since damage to the indication device may result.

4.4 Final measurements

When insulation resistance is performed in conjunction with environmental tests, the specimens
shall be measured within one hour, unless otherwise specified in the referencing document.

5 Details to be specified

The following details shall be specified in the referencing document:

5.1 Test specimen preparations or conditioning, if required; see 3.2.1

5.2 Magnitude of test voltage, if other than 500 Vdc; see 4.1. (Typical dc test voltages are
100 V, 500 V, 1000 V and 1500 V)

5.3 Electrification time, if other than two minutes; see 4.2

5.4 Points of application of test voltage, if other than specified in 4.1

5.5 The minimum value of insulation resistance; see annex A

5.6 Environmental conditions for test if other than standard conditions. (Barometric pressure,
temperature and relative humidity)

5.7 Define test specimen (mated or unmated)

5.8 Number of specimens to be tested

5.9 Number of readings per specimen

5.10 Specimen description including fixture, if applicable

中国可靠性网 http://www.kekaoxing.com
EIA-364-21C
Page 4

6 Test documentation

Documentation shall contain the details specified in clause 5, with any exceptions, and the
following:

6.1 Title of test

6.2 Specimen description including fixturing, if applicable

6.3 Test equipment used, and date of last and next calibration

6.4 Test procedure

6.5 Values and observations

6.6 Name of operator and date of test

 EIA-364-21C
Page A-1

Annex A

A Informative

A.1 This test procedure is used for determining the resistance offered by the insulation materials
and the various seals of a connector to a dc potential tending to produce a leakage of current
through or on the surface of these members. This test is especially useful in determining the
extent to which insulating properties are affected by deteriorating influences, such as heat,
moisture, contamination, or loss of volatile materials.

A.2 The purpose of the insulation resistance test is to measure the resistance offered by the
insulating members of a component part to an impressed direct voltage tending to produce a
leakage current through or on the surface of these members. The value of insulation resistance
may be the limiting factor in the design of high-impedance circuits, and can disturb the operation
of circuits intended to be isolated, for example, by forming feedback loops. Excessive leakage
currents can lead to deterioration of insulation by heating or by direct current effects. Insulation
resistance measurements are not equivalent to dielectric withstanding voltage or dielectric
breakdown test.

A.3 Since members composed of different materials or combinations of materials may have
inherently different insulation resistance values, the numerical value of measured insulation
resistance cannot be taken as a direct measure of the degree of cleanliness or absence of
deterioration. The test is especially helpful in determining the extent to which insulation is
affected by deteriorating influences.

A.4 The following situations should be considered while formulating the testing requirements of
an item where insulation resistance is tested:

A.4.1 Test potential applied (voltage range) should be of the same range as that of the connector
use and expected voltage spike that the connector is expected to see in its use.

A.4.2 Connector insulation resistance values will vary depending on contact size, composition of
contact and insulator, and distance between test points. However, designers specifying test
values should realize that connectors of identical properties should have identical resistance
values specified.

中国可靠性网 http://www.kekaoxing.com
 EIA Document Improvement Proposal

If in the review or use of this document, a potential change is made evident for safety, health or
technical reasons, please fill in the appropriate information below and mail or FAX to:

Electronic Industries Alliance

Engineering Department – Publications Office
2500 Wilson Blvd.
Arlington, VA 22201
FAX: (703) 907-7501

Document No. Document Title:

Submitter’s Name: Telephone No.:

FAX No.:
e-mail:

Address:

Urgency of Change:

Immediate: At next revision:

Problem Area:
a. Clause Number and/or Drawing:

b. Recommended Changes:

c. Reason/Rationale for Recommendation:

Additional Remarks:

Signature: Date:

FOR EIA USE ONLY

Responsible Committee:

Chairman:

Date comments forwarded to Committee Chairman:

中国可靠性网 http://www.kekaoxing.com