ASTM F2490-20
(Guide)Standard Guide for Aircraft Electrical Load and Power Source Capacity Analysis
Standard Guide for Aircraft Electrical Load and Power Source Capacity Analysis
SIGNIFICANCE AND USE
4.1 To show compliance with 14 CFR 23.1351, you must determine the electrical system capacity.
4.2 14 CFR 23.1351(a)(2) states that:
4.2.1 For normal, utility, and acrobatic category airplanes, by an electrical load analysis or by electrical measurements that account for the electrical loads applied to the electrical system in probable combinations and for probable durations; and
4.2.2 For commuter category airplanes, by an electrical load analysis that accounts for the electrical loads applied to the electrical system in probable combinations and for probable durations.
4.3 The primary purpose of the electrical load analysis (ELA) is to determine electrical system capacity (including generating sources, converters, contactors, bus bars, and so forth) needed to supply the worst-case combinations of electrical loads. This is achieved by evaluating the average demand and maximum demands under all applicable flight conditions. A summary can then be used to relate the ELA to the system capacity and can establish the adequacy of the power sources under normal, abnormal, and emergency conditions.
Note 1: The ELA should be maintained throughout the life of the aircraft to record changes to the electrical system, which may add or remove electrical loads to the system.
4.4 The ELA that is produced for aircraft-type certification should be used as the baseline document for any subsequent changes. When possible, the basic format of the original ELA should be followed to ensure consistency in the methodology and approach.
4.5 The original ELA may be lacking in certain information, for instance, time available on emergency battery. It may be necessary to update the ELA using the guidance material contained in this guide.
SCOPE
1.1 This guide covers how to prepare an electrical load analysis (ELA) to meet Federal Aviation Administration (FAA) requirements.
1.2 This guide is intended to address aircraft level electrical load analysis. Electric propulsive power load analysis was not considered in the development of this guide.
1.3 The values stated in SI units are to be regarded as standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2490 − 20
Standard Guide for
Aircraft Electrical Load and Power Source Capacity
1
Analysis
This standard is issued under the fixed designation F2490; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 14 CFR 23.1529Normal, Utility, Acrobatic, and Commuter
Category Airplanes—Instructions for Continued Airwor-
1.1 This guide covers how to prepare an electrical load
thiness
analysis(ELA)tomeetFederalAviationAdministration(FAA)
14 CFR 91General Operating and Flight Rules
requirements.
14 CFR 135.163Operating Requirements: Commuter and
1.2 This guide is intended to address aircraft level electrical
On Demand Operations and Rules Governing Persons on
load analysis. Electric propulsive power load analysis was not
Board Such Aircraft—Equipment Requirements: Aircraft
considered in the development of this guide.
Carrying Passengers under IFR
1.3 The values stated in SI units are to be regarded as
standard. 3. Terminology
1.4 This standard does not purport to address all of the
3.1 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
3.1.1 abnormal electrical power operation (or abnormal
responsibility of the user of this standard to establish appro-
operation), n—occurs when a malfunction or failure in the
priate safety, health, and environmental practices and deter-
electric system has taken place and the protective devices of
mine the applicability of regulatory limitations prior to use.
the system are operating to remove the malfunction or failure
1.5 This international standard was developed in accor-
fromtheremainderofthesystembeforethelimitsofabnormal
dance with internationally recognized principles on standard-
operation are exceeded.
ization established in the Decision on Principles for the
3.1.1.1 Discussion—The power source may operate in a
Development of International Standards, Guides and Recom-
degraded mode on a continuous basis when the power charac-
mendations issued by the World Trade Organization Technical
teristics supplied to the using equipment exceed normal opera-
Barriers to Trade (TBT) Committee.
tionlimitsbutremainwithinthelimitsforabnormaloperation.
3.1.2 alternate source, n—secondpowersourcethatmaybe
2. Referenced Documents
used instead of the normal source, usually on failure of the
2
2.1 FAA Aeronautics and Space Airworthiness Standards:
normal source.
14 CFR 23.1309Normal, Utility, Acrobatic, and Commuter
3.1.2.1 Discussion—The use of alternate sources creates a
Category Airplanes—Equipment, Systems, and Installa-
new load and power configuration and, therefore, a new
tions
electrical system that may require separate source capacity
14 CFR 23.1351Normal, Utility, Acrobatic, and Commuter
analysis.
Category Airplanes—General
3.1.3 cruise, n—condition during which the aircraft is in
14 CFR 23.1353Normal, Utility, Acrobatic, and Commuter
level flight.
Category Airplanes—Storage Battery Design and Instal-
3.1.4 electrical source, n—electrical equipment that
lation
produces, converts, or transforms electrical power.
14 CFR 23.1419Normal, Utility, Acrobatic, and Commuter
Category Airplanes—Ice Protection 3.1.5 electrical system, n—consists of an electrical power
source, the electrical wiring interconnection system, and the
electrical load(s) connected to that system.
1
This guide is under the jurisdiction of ASTM Committee F39 on Aircraft
3.1.6 emergency electrical power operation (or emergency
Systems and is the direct responsibility of Subcommittee F39.01 on Design,
operation), n—condition that occurs following a loss of all
Alteration, and Certification of Electrical Systems.
CurrenteditionapprovedJune1,2020.PublishedJuly2020.Originallyapproved
normalelectricalgeneratingpowersourcesoranothermalfunc-
in 2005. Last previous edition approved in 2013 as F2490–05 (2013). DOI:
tion that results in operation on standby power (batteries or
10.1520/F2490-20.
2
other emergency generating source such as an auxiliary power
Available from U.S. Government Publishing Office (GPO), 732 N. Capitol St.,
NW, Washington, DC 20401, http://www.gpo.gov. unit (APU) or ram air turbine (RAT)) only, or both).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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F2490 − 20
3.1.7 ground operation and loading, n—time spent in pre- changes. When possible, the basic format
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2490 − 05 (Reapproved 2013) F2490 − 20
Standard Guide for
Aircraft Electrical Load and Power Source Capacity
1
Analysis
This standard is issued under the fixed designation F2490; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide covers how to prepare an electrical load analysis (ELA) to meet Federal Aviation Administration (FAA)
requirements.
1.2 This guide is intended to address aircraft level electrical load analysis. Electric propulsive power load analysis was not
considered in the development of this guide.
1.3 The values givenstated in SI units are to be regarded as the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 FAA Aeronautics and Space Airworthiness Standards:
14 CFR 23.1309 Normal, Utility, Acrobatic, and Commuter Category Airplanes—Equipment, Systems, and Installations
14 CFR 23.1351 Normal, Utility, Acrobatic, and Commuter Category Airplanes—General
14 CFR 23.1353 Normal, Utility, Acrobatic, and Commuter Category Airplanes—Storage Battery Design and Installation
14 CFR 23.1419 Normal, Utility, Acrobatic, and Commuter Category Airplanes—Ice Protection
14 CFR 23.1529 Normal, Utility, Acrobatic, and Commuter Category Airplanes—Instructions for Continued Airworthiness
14 CFR 91 General Operating and Flight Rules
14 CFR 135.163 Operating Requirements: Commuter and On Demand Operations and Rules Governing Persons on Board Such
Aircraft—Equipment Requirements: Aircraft Carrying Passengers under IFR
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 abnormal electrical power operation (or abnormal operation), n—occurs when a malfunction or failure in the electric
system has taken place and the protective devices of the system are operating to remove the malfunction or failure from the
remainder of the system before the limits of abnormal operation are exceeded.
3.1.1.1 Discussion—
The power source may operate in a degraded mode on a continuous basis when the power characteristics supplied to the using
equipment exceed normal operation limits but remain within the limits for abnormal operation.
3.1.2 alternate source, n—second power source that may be used instead of the normal source, usually on failure of the normal
source.
1
This guide is under the jurisdiction of ASTM Committee F39 on Aircraft Systems and is the direct responsibility of Subcommittee F39.01 on Design, Alteration, and
Certification of Electrical Systems.
Current edition approved July 1, 2013June 1, 2020. Published September 2013July 2020. Originally approved in 2005. Last previous edition approved in 20052013 as
ε1
F2490 – 05 (2013). . DOI: 10.1520/F2490-05R13.10.1520/F2490-20.
2
Available from U.S. Government Printing Office Superintendent of Documents, Publishing Office (GPO), 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC
20401.20401, http://www.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
F2490 − 20
3.1.2.1 Discussion—
The use of alternate sources creates a new load and power configuration and, therefore, a new electrical system that may require
separate source capacity analysis.
3.1.3 cruise, n—condition during which the aircraft is in level flight.
3.1.4 electrical source, n—electrical equipment that produces, converts, or transforms electrical power.
3.1.5 electrical system, n—consists of an electrical power source, the electrical wiring interconnection system, and the electrical
load(s) connected to that system.
3.1.6 emergency electrical power operation (or emergency operation), n—condition that occurs following a loss of all
...
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