14 C.F.R. § 25.1353 Electrical equipment and installations.
Title 14 - Aeronautics and Space
(a) Electrical equipment, controls, and wiring must be installed so that operations of any one unit or system of units will not adversely affect the simultaneous operation of any other electrical unit or system essential to the safe operation. Any electrical interference likely to be present in the airplane must not result in hazardous effects upon the airplane or its systems except under extremely remote conditions. (b) Cables must be grouped, routed, and spaced so that damage 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 and pressures must be maintained during any probable charging or discharging condition. No uncontrolled increase in cell temperature may result when the battery is recharged (after previous complete discharge)— (i) At maximum regulated voltage or power; (ii) During a flight of maximum duration; and (iii) Under the most adverse cooling condition likely to occur in service. (2) Compliance with paragraph (c)(1) of this section must be shown by test unless experience with similar batteries and installations has shown that maintaining safe cell temperatures and pressures presents no problem. (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 accumulate in hazardous quantities within the airplane. (4) No corrosive fluids or gases that may escape from the battery may damage surrounding airplane structures or adjacent essential equipment. (5) Each nickel cadmium battery installation must have provisions to prevent any hazardous effect on structure or essential systems that may be caused by the maximum amount of heat the battery can generate during a short circuit of the battery or of individual cells. (6) Nickel cadmium battery installations must have— (i) A system to control the charging rate of the battery automatically so as to prevent battery overheating; or (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) A battery failure sensing and warning system with a means for disconnecting the battery from its charging source in the event of battery failure. (d) Electrical cables and cable installations must be designed and installed as follows: (1) The electrical cables used must be compatible with the circuit protection devices required by §25.1357 of this part, such that a fire or smoke hazard cannot be created under temporary or continuous fault conditions. (2) Means of permanent identification must be provided for electrical cables, connectors and terminals. (3) Electrical cables must be installed such that the risk of mechanical damage and/or damage caused by fluids, vapors, or sources of heat, is minimized. [Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25–41, 42 FR 36970, July 18, 1977; Amdt. 25–42, 43 FR 2323, Jan. 16, 1978; Amdt. 25–113, 69 FR 12530, Mar. 16, 2004]
Title 14: Aeronautics and Space
PART 25—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
Subpart F—Equipment
Electrical Systems and Equipment
§ 25.1353 Electrical equipment and installations.
