Current through Register Vol. 48, No. 9, September 27, 2024
On every motor vehicle, every heater shall comply with
the following requirements:
(a)
Prohibited types of heaters. The installation or use of the following types of
heaters is prohibited:
(1) Exhaust heaters.
Any type of exhaust heater in which the engine exhaust gases are conducted into
or through any space occupied by persons or any heater which conducts engine
compartment air into any such space.
(2) Unenclosed flame heaters. Any type of
heater employing a flame which is not fully enclosed, except that such heaters
are not prohibited when used for heating the cargo of tank motor
vehicles.
(3) Heaters permitting
fuel leakage. Any type of heater from the burner of which there could be
spillage or leakage of fuel upon the tilting or overturning of the vehicle in
which it is mounted.
(4) Heaters
permitting air contamination. Any heater taking air, heated or to be heated,
from the engine compartment or from direct contact with any portion of the
exhaust system; or any heater taking air in ducts from the outside atmosphere
to be conveyed through the engine compartment, unless said ducts are so
constructed and installed as to prevent contamination of the air so conveyed by
exhaust or engine compartment gases.
(5) Solid fuel heaters except wood charcoal.
Any stove or other heater employing solid fuel except wood charcoal.
(6) Portable heaters. Portable heaters shall
not be used in any space occupied by persons except the cargo space of motor
vehicles which are being loaded or unloaded.
(b) Heater specifications. All heaters shall
comply with the following specifications:
(1)
Heating elements, protection. Every heater shall be so located or protected as
to prevent contact therewith by occupants, unless the surface temperature of
the protecting grilles or of any exposed portions of the heaters, inclusive of
exhaust stacks, pipes, or conduits shall be lower than would cause contact
burns. Adequate protection shall be afforded against igniting parts of the
vehicle or burning occupants by direct radiation. Wood charcoal heaters shall
be enclosed within a metal barrel, drum, or similar protective enclosure which
enclosure shall be provided with a securely fastened cover.
(2) Moving parts, guards. Effective guards
shall be provided for the protection of passengers or occupants against injury
by fans, belts, or any other moving parts.
(3) Heaters, secured. Every heater and every
heater enclosure shall be securely fastened to the vehicle in a substantial
manner so as to provide against relative motion within the vehicle during
normal usage or in the event the vehicle overturns. Every heater shall be so
designed, constructed, and mounted as to minimize the likelihood of disassembly
of any of its parts, including exhaust stacks, pipes, or conduits, upon
overturn of the vehicle in or on which it is mounted. Wood charcoal heaters
shall be secured against relative motion within the enclosure required by
paragraph (c)(1), and the enclosure shall be securely fastened to the motor
vehicle.
(4) Relative motion
between fuel tank and heater. When either in normal operation or in the event
of overturn, there is or is likely to be relative motion between the fuel tank
for a heater and the heater, or between either of such units and the fuel lines
between them, a suitable means shall be provided at the point of greatest
relative motion so as to allow this motion without causing failure of the fuel
lines.
(5) [Reserved]
(6) Heater hoses. Hoses for all hot water and
steam heater systems shall be specifically designed and constructed for that
purpose.
(7) Electrical apparatus.
Every heater employing any electrical apparatus shall be equipped with
electrical conductors, switches, connectors, and other electrical parts of
ample current carrying capacity to provide against overheating; any electric
motor employed in any heater shall be of adequate size and so located that it
will not be overheated; electrical circuits shall be provided with fuses and/or
circuit breakers to provide against electrical overloading; and all electrical
conductors employed in or leading to any heater shall be secured against
dangling, chafing, and rubbing and shall have suitable protection against any
other condition likely to produce short or open circuits.
(8) Storage battery caps. If a separate
storage battery is located within the personnel or cargo space, such battery
shall be securely mounted and equipped with nonspill filler caps.
(9) Combustion heater exhaust construction.
Every heater employing the combustion of oil, gas, liquefied petroleum gas, or
any other combustible material shall be provided with substantial means of
conducting the products of combustion to the outside of the vehicle:
Provided, however, That this requirement shall not apply
to heaters used solely to heat the cargo space of motor vehicles where such
motor vehicles or heaters are equipped with means specifically designed and
maintained so that the carbon monoxide concentration will never exceed 0.2
percent in the cargo space. The exhaust pipe, stack, or conduit if required
shall be sufficiently substantial and so secured as to provide reasonable
assurance against leakage or discharge of products of combustion within the
vehicle and, if necessary, shall be so insulated as to make unlikely the
burning or charring of parts of the vehicle by radiation or by direct contact.
The place of discharge of the products of combustion to the atmosphere and the
means of discharge of such products shall be such as to minimize the likelihood
of their reentry into the vehicle under all operating conditions.
(10) Combustion chamber
construction. The design and construction of any combustion type heater except
cargo space heaters permitted by the proviso of paragraph (c)(9) and unenclosed
flame heaters used for heating cargo of tank motor vehicles shall be such as to
provide against the leakage of products of combustion into air to be heated and
circulated. The material employed in combustion chambers shall be such as to
provide against leakage because of corrosion, oxidation, or other
deterioration. Joints between combustion chambers and the air chambers with
which they are in thermal and mechanical contact shall be so designed and
constructed as to prevent leakage between the chambers and the materials
employed in such joints shall have melting points substantially higher than the
maximum temperatures likely to be attained at the points of jointure.
(11) [Reserved]
(12) Heater, automatic fuel control. Gravity
or siphon feed shall not be permitted for heaters using liquid fuels. Heaters
using liquid fuels shall be equipped with automatic means for shutting off the
fuel or for reducing such flow of fuel to the smallest practicable magnitude,
in the event of overturn of the vehicle. Heaters using liquefied petroleum gas
as fuel shall have the fuel line equipped with automatic means at the source of
supply for shutting off the fuel in the event of separation, breakage, or
disconnection of any of the fuel lines between the supply source and the
heater.
(13) "Tell tale"
indicators. Heaters subject to paragraph (c)(14) and not provided with
automatic controls shall be provided with "tell tale" means to indicate to the
driver that the heater is properly functioning. This requirement shall not
apply to heaters used solely for the cargo space in semitrailers or full
trailers.
(14) Shut off control.
Automatic means, or manual means if the control is readily accessible to the
driver without moving from the driver's seat, shall be provided to shut off the
fuel and electrical supply in case of failure of the heater to function for any
reason, or in case the heater should function improperly or overheat. This
requirement shall not apply to wood charcoal heaters or to heaters used solely
to heat the contents of cargo tank motor vehicles, but wood charcoal heaters
must be provided with a controlled method of regulating the flow of combustion
air.
(15) Certification required.
Every combustion type heater, except wood charcoal heaters, the date of
manufacture of which is subsequent to December 31, 1952, and every wood
charcoal heater, the date of manufacture of which is subsequent to September 1,
1953, shall be marked plainly to indicate the type of service for which such
heater is designed and with a certification by the manufacturer that the heater
meets the applicable requirements for such use. For example," Meets I.C.C. Flue
Vented Cargo Space Heater Requirements," and after December 31, 1967, such
certification shall read" "Meets FHWA Flue Vented Cargo Space Heater
Requirements," etc.
(i) Exception. The
certification for a catalytic heater which is used in transporting flammable
liquid or gas shall be as prescribed under Section 177.834(1) of the Federal
Motor Carrier Safety Administration's hazardous materials
regulations.