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14 CFR Ch. I (1–1–19 Edition)
§ 29.1355
(4) No corrosive fluids or gases that
may escape from the battery may dam-
age surrounding structures or adjacent
essential equipment.
(5) Each nickel cadmium battery in-
stallation capable of being used to
start an engine or auxiliary power unit
must have provisions to prevent any
hazardous effect on structure or essen-
tial systems that may be caused by the
maximum amount of heat the battery
can generate during a short circuit of
the battery or of its individual cells.
(6) Nickel cadmium battery installa-
tions capable of being used to start an
engine or auxiliary power unit must
have—
(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 condi-
tion; or
(iii) A battery failure sensing and
warning system with a means for dis-
connecting the battery from its charg-
ing source in the event of battery fail-
ure.
(Secs. 313(a), 601, 603, 604, and 605 of the Fed-
eral Aviation Act of 1958 (49 U.S.C. 1354(a),
1421, 1423, 1424, and 1425); and sec. 6(c), Dept.
of Transportation Act (49 U.S.C. 1655(c)))
[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–14, 42 FR 36973, July 18,
1977; Amdt. 29–15, 43 FR 2327, Jan. 16, 1978]
§ 29.1355
Distribution system.
(a) The distribution system includes
the distribution busses, their associ-
ated feeders, and each control and pro-
tective device.
(b) If two independent sources of
electrical power for particular equip-
ment or systems are required by this
chapter, in the event of the failure of
one power source for such equipment or
system, another power source (includ-
ing its separate feeder) must be pro-
vided automatically or be manually se-
lectable to maintain equipment or sys-
tem operation.
(Secs. 313(a), 601, 603, 604, and 605 of the Fed-
eral Aviation Act of 1958 (49 U.S.C. 1354(a),
1421, 1423, 1424, and 1425); and sec. 6(c), Dept.
of Transportation Act (49 U.S.C. 1655(c)))
[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–14, 42 FR 36973, July 18,
1977; Amdt. 29–24, 49 FR 44439, Nov. 6, 1984]
§ 29.1357
Circuit protective devices.
(a) Automatic protective devices
must be used to minimize distress to
the electrical system and hazard to the
rotorcraft system and hazard to the
rotorcraft in the event of wiring faults
or serious malfunction of the system or
connected equipment.
(b) The protective and control de-
vices in the generating system must be
designed to de-energize and disconnect
faulty power sources and power trans-
mission equipment from their associ-
ated buses with sufficient rapidity to
provide protection from hazardous
overvoltage and other malfunctioning.
(c) Each resettable circuit protective
device must be designed so that, when
an overload or circuit fault exists, it
will open the circuit regardless of the
position of the operating control.
(d) If the ability to reset a circuit
breaker or replace a fuse is essential to
safety in flight, that circuit breaker or
fuse must be located and identified so
that it can be readily reset or replaced
in flight.
(e) Each essential load must have in-
dividual circuit protection. However,
individual protection for each circuit
in an essential load system (such as
each position light circuit in a system)
is not required.
(f) If fuses are used, there must be
spare fuses for use in flight equal to at
least 50 percent of the number of fuses
of each rating required for complete
circuit protection.
(g) Automatic reset circuit breakers
may be used as integral protectors for
electrical equipment provided there is
circuit protection for the cable sup-
plying power to the equipment.
[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–24, 49 FR 44440, Nov. 6,
1984]
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