[Code of Federal Regulations]

[Title 49, Volume 4]

[Revised as of October 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 49CFR238.225]



[Page 672]

 

                        TITLE 49--TRANSPORTATION

 

       CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF 

                             TRANSPORTATION

 

PART 238_PASSENGER EQUIPMENT SAFETY STANDARDS--Table of Contents

 

     Subpart C_Specific Requirements for Tier I Passenger Equipment

 

Sec. 238.225  Electrical system.



    All passenger equipment shall comply with the following:

    (a) Conductors. Conductor sizes shall be selected on the basis of 

current-carrying capacity, mechanical strength, temperature, flexibility 

requirements, and maximum allowable voltage drop. Current-carrying 

capacity shall be derated for grouping and for operating temperature.

    (b) Main battery system.

    (1) The main battery compartment shall be isolated from the cab and 

passenger seating areas by a non-combustible barrier.

    (2) Battery chargers shall be designed to protect against 

overcharging.

    (3) If batteries are of the type to potentially vent explosive 

gases, the battery compartment shall be adequately ventilated to prevent 

the accumulation of explosive concentrations of these gases.

    (c) Power dissipation resistors.

    (1) Power dissipating resistors shall be adequately ventilated to 

prevent overheating under worst-case operating conditions as determined 

by the railroad.

    (2) Power dissipation grids shall be designed and installed with 

sufficient isolation to prevent combustion.

    (3) Resistor elements shall be electrically insulated from resistor 

frames, and the frames shall be electrically insulated from the supports 

that hold them.

    (d) Electromagnetic interference and compatibility. (1) The 

operating railroad shall ensure electromagnetic compatibility of the 

safety-critical equipment systems with their environment. 

Electromagnetic compatibility may be achieved through equipment design 

or changes to the operating environment.

    (2) The electronic equipment shall not produce electrical noise that 

affects the safe performance of train line control and communications or 

wayside signaling systems.

    (3) To contain electromagnetic interference emissions, suppression 

of transients shall be at the source wherever possible.

    (4) All electronic equipment shall be self-protected from damage or 

improper operation, or both, due to high voltage transients and long-

term over-voltage or under-voltage conditions. This includes protection 

from both power frequency and harmonic effects as well as protection 

from radio frequency signals into the microwave frequency range.