(c)
Externalpower. Ifprovisions are madefor connecting externalpower to the airplane, and that externalpower canbe electrically connected to equipment other than that usedforengine starting, meansmustbeprovided to ensurethat no externalpower supply having a reversepolarity, or a reversephase sequence, can supplypowerto the airplane’s electrical system.
(d)
Operation without normal electrical power. It must be shown by analysis, tests, or both, that the airplane can be operated safely in VFR conditions, for a period or notlessthan .veminutes,withthenormal electricalpower(electricalpowersources excluding thebattery) inoperative, with criticaltypefuel(from the standpoint of .ameout and restart capability), and with the airplane initially at the maximum certi.cated altitude. Parts of the electrical system may remain on if–
(1)
[A single malfunction, including a wire bundle or junction box .re, cannot result in loss of both the part turned o. and the part turned on; and
(2)
The parts turned on are electrically and mechanically isolated from the parts turned o..]
Amdt. 25-72, E.. 8/20/90
FAR 25.1353 : Electrical equipment and installations.
(a) Electrical equipment, controls, and wiring mustbe installed so that operation of any one unit or system of units will not adversely a.ect the simultaneous operation of any other electrical unit or system essential to the safe operation.
(b)
Cables mustbegrouped, routed, and spaced so thatdamage to essential circuits will be minimized if there are faults in heavy current-carrying cables.
(c)
Storage batteries must be designed and installed as follows :
(1)
Safe cell temperatures andpressuresmustbe maintainedduring anyprobable charging ordischarging condition.No uncontrolledincreasein celltemperature may result when the batteryis recharged(afterprevious completedischarge)–
(i)
At maximum regulated voltage orpower;
(ii)
During a .ight of maximum duration; and
(iii) Under the most adverse cooling condition likely to occur in service.
(2)
Compliance with subparagraph(1) of thisparagraph mustbe shownby test unless experience with similarbatteries andinstallationshas shown that main-taining safe celltemperatures andpressurespresents noproblem.
(3)
No explosive or toxic gases emitted by any battery in normal operation, or as the result of any probable malfunction in the charging system or battery installation may accumulateinhazardousquantities withinthe airplane.
(4)
No corrosive .uids or gases that may escape from the battery may damage surrounding airplane structures or adjacent essential equipment.
(5)
Each nickel cadmium battery installation capable of being used to start an engine orauxiliarypowerunit musthaveprovisionstopreventanyhazardous e.ect on structure or essential systems that may be caused by the maximum amount ofheatthebattery cangenerateduring a short circuit of thebattery or of its individual cells.
(6)
[Nickelcadmium battery installations capable of being used to start an engine or auxiliarypower unit musthave–
(i)
A system to control the charging rate of the battery automatically so as to prevent battery overheating;
(ii)
A battery temperature sensing and over-temperature warning system with a means for disconnecting the battery from its charging source in the event of an over-temperature condition; or
(iii) Abatteryfailure sensingand warning system with a meansfordisconnec-ting the battery from its charging source in the event of battery failure.]
Amdt. 25-42, E.. 3/1/78
FAR 25.1355 : Distribution system.
(a)
The distribution system includes the distribution busses, their associated feeders, and each control and protective device.
(b)
[Revoked.]
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 4(23)
