FprEN 2591-217

• Abstract:

  This document specifies a method for measuring the voltage drop under specified current in terminal lugs and in-line splices.; It is used together with EN 2591-100.

• Status: Not Published
• Publication Date: 10-Mar-2027
• ICS: 49.060 - Aerospace electric equipment and systems
• ICS: 49.090 - On-board equipment and instruments
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 2/S 3 - Elements of Connection (Connectors, Contacts, rear accessories, crimping tools
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 06-Aug-2026
• Completion Date: 06-Aug-2026
• Ref Project: oSIST prEN 2591-217:2026 - Aerospace series - Elements of electrical and optical connection - Test methods - Part 217: Voltage drop under specified current for terminal lugs and in-line splices

• Revises: EN 2591-217:2002 - Aerospace series - Elements of electrical and optical connection - Test methods - Part 217: Voltage drop under specified current for terminal lugs and in-line splices
• Effective Date: 19-Jan-2023

FprEN 2591-217 is a draft CEN European Standard for aerospace electrical and optical connection elements. It specifies a test method for measuring voltage drop under specified current in terminal lugs and in-line splices, so users can compare crimp or splice performance under controlled conditions. It is written for test laboratories, connector and cable assembly makers, and aerospace buyers or quality teams who need a common way to verify electrical connection performance.

What does FprEN 2591-217 specify?

FprEN 2591-217 specifies one test method: measuring voltage drop under a specified current in terminal lugs and in-line splices. The document is intended to be used together with EN 2591-100, which provides the general test-method framework.

FprEN 2591-217 is organized into a short technical structure:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Clause 4 - Preparation of specimens
• Clause 5 - Method
• Bibliography

For a reader, this means the document is narrowly focused on test execution and result calculation, not on product design or acceptance rules outside the test itself.

What are the key requirements of FprEN 2591-217?

FprEN 2591-217 sets out how to prepare specimens, how to measure them, and how to calculate the voltage drop of the connection. The practical aim is to make the test repeatable and to ensure the result can be judged against the value required in the technical specification.

Specimen preparation and test setup

Clause 4 requires specimens to be fitted with their normal accessories and wired in accordance with the technical specification. That specification must state the number of specimens, the cable type, installation and wiring, the distance L between measurement points, the test current, the accessories fitted, and whether initial and final measurements are required.

In practice, this means the test plan has to be fixed before testing starts. If the cable, wiring, or accessories are not controlled, the voltage-drop result will not be comparable from one test to another.

Measurement principle

Clause 5 measures the voltage drop of the specimen and the voltage drop of a reference cable at the same measuring points. The voltage drop of the connection is then calculated by subtracting the reference-cable drop from the specimen drop.

This matters because the result should reflect the connection itself, not the full length of conductor used in the setup. The method therefore isolates the effect of the terminal lug or splice.

Acceptance and calculation

Clause 5 states that the calculated voltage drop of the crimp shall not exceed the value specified in the technical specification. For terminal lugs, Formula (1) applies, and for in-line splices, Formula (2) applies.

For users, this means the technical specification must define the pass/fail limit. The standard gives the calculation method, but the acceptance value comes from the product specification or test plan.

Temperature correction and measurement distance

Clause 5 also allows voltage-drop values to be normalized at 20 °C when the technical specification requires it. The document gives Formula (3) for that correction. It also states that if the distance between measurement points differs from L, the measured values shall be adjusted mathematically to that distance.

This is important when tests are done at different temperatures or with slightly different setups. It helps keep results comparable across laboratories and over time.

Test assemblies

Clause 5 refers to Figure 1 for terminal lugs and Figure 2 for in-line splices. These figures show the measurement assembly and where the measuring points are located.

For the tester, the figures define the physical arrangement of the measurement points, which is critical to getting a valid voltage-drop reading.

Who uses FprEN 2591-217?

FprEN 2591-217 is used in aerospace electrical and optical connection work, especially where terminal lugs and in-line splices must be tested for electrical performance. It is relevant to manufacturers of crimped connections, test laboratories, quality assurance teams, and buyers who need a common test method in technical specifications.

It is also useful during qualification, incoming inspection, and product verification, because it gives one agreed way to measure voltage drop under load.

What changed in FprEN 2591-217 from the previous edition?

FprEN 2591-217 supersedes EN 2591-217:2002. The foreword states two significant technical changes:

• a formula was added to normalize measurements at 20 °C, reflecting common practice for power terminal lugs and splices
• the measurement points in Figure 1 and Figure 2 were corrected

For users, this means the revised draft gives clearer temperature correction and a corrected test arrangement.

Which standards are used with FprEN 2591-217?

FprEN 2591-217 is used together with EN 2591-100. That companion standard provides the general test-method requirements for the EN 2591 series, while Part 217 supplies the specific procedure for voltage drop under specified current.

What does the FprEN 2591-217 document contain?

FprEN 2591-217 contains the test scope, the specimen-preparation rules, the measurement method, and the calculation formulas for terminal lugs and in-line splices. It also includes two figures showing the measurement assemblies and a bibliography entry for EN 2591-100.

The main technical content is procedural: how to set up the test, where to measure, how to calculate the connection voltage drop, and when to normalize values to 20 °C. That makes the document useful for laboratory methods, verification testing, and writing product-specific technical specifications.

SLOVENSKI STANDARD
01-marec-2026
Aeronavtika - Električni in optični spojni elementi - Preskusne metode - 217. del:
Padec napetosti pri določenem toku za kabelske čevlje in vrstne spojke
Aerospace series - Elements of electrical and optical connection - Test methods - Part
217: Voltage drop under specified current for terminal lugs and in-line splices
Luft- und Raumfahrt - Elektrische und optische Verbindungselemente; Prüfverfahren -
Teil 217: Spannungsabfall bei festgelegtem Strom für Kabelschuhe und Stoßverbinder
Ta slovenski standard je istoveten z: prEN 2591-217
ICS:
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
prEN 2591-217
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2025
ICS 49.060 Will supersede EN 2591-217:2002
English Version
Aerospace series - Elements of electrical and optical
connection - Test methods - Part 217: Voltage drop under
specified current for terminal lugs and in-line splices
Luft- und Raumfahrt - Elektrische und optische
Verbindungselemente; Prüfverfahren - Teil 217:
Spannungsabfall bei festgelegtem Strom für
Kabelschuhe und Stoßverbinder
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
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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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 2591-217:2025 E
worldwide for CEN national Members.

prEN 2591-217:2025 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Preparation of specimens . 4
5 Method .
...