[Code of Federal Regulations]
[Title 40, Volume 18]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR92.106]

[Page 424]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 92--CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES--
Table of Contents
 
                       Subpart B--Test Procedures
 
Sec. 92.106  Equipment for loading the engine.

    For purposes of placing the required load on the engine during an 
emissions test, either the equipment specified in paragraph (a) of this 
section, or the equipment specified in paragraph (b) of this section may 
be used.
    (a) Locomotive testing. (1) The equipment required for loading the 
locomotive engine-alternator/generator assembly electrically, and for 
measurement of the electrical power output from the alternator/generator 
consists of the following, either in total or in part: electrical 
resistance load bank; fans or other means for cooling of the load bank; 
wattmeter, including phase angle compensation; meter(s) for measurement 
of the current through the load bank (a calibrated electrical shunt and 
voltmeter is allowed for current measurement); meter(s) to measure the 
voltage across the load bank; and electrical cable to connect the 
alternator/generator to the load bank. Many locomotives are equipped 
with an internal electrical resistance load bank and fans for cooling of 
the load bank; when so equipped, the locomotive load bank may be used 
for purposes of loading the engine during emissions tests.
    (2) The combination of instruments (meters) used to measure engine 
or alternator/generator power output (wattmeter, ammeter, voltmeter) 
shall have accuracy and precision such that the accuracy of the measured 
alternator/generator power out is better than:
    (i) 2 percent of point at all power settings except idle and dynamic 
brake; and
    (ii) Less accuracy and precision is allowed at idle and dynamic 
brake, consistent with good engineering practice. Equipment with 
accuracy or precision worse than 20 percent of point is not allowed.
    (3) The efficiency curve for the alternator/generator, shall specify 
the efficiency at each test point. The manufacturer or remanufacturer 
shall provide EPA with a detailed description of the procedures used to 
establish the alternator/generator efficiency.
    (b) Engine testing. (1) For engine testing using a dynamometer, the 
engine dynamometer system must be capable of controlling engine torque 
and speed simultaneously under steady speed operation, during 
accelerations where the rate of change in torque and speed is 
representative of those changes which occur when the engine is operating 
in a locomotive. It must also be capable of performing the test sequence 
described in this subpart. In addition to these general requirements, 
the engine or dynamometer readout signals for speed and torque shall 
meet the following accuracy specifications:
    (i) Engine speed readout shall be accurate to within 2 
percent of the absolute standard value, as defined in Sec. 92.116 of 
this part.
    (ii) Engine flywheel torque readout shall be accurate to either 
within 3 percent of the NIST ``true'' value torque, or the 
following accuracies, whichever provides the most accurate readout:
    (A) 20 ft.-lbs. of the NIST ``true'' value if the full 
scale value is 9000 ft.-lbs. or less.
    (B) 30 ft.-lbs., of the NIST ``true'' value if the full 
scale value is greater than 9000 ft.-lbs.
    (C) Option. Internal dynamometer signals (i.e., armature current, 
etc.) may be used for torque measurement provided that it can be shown 
that the engine flywheel torque during the test sequence conforms to the 
accuracy specifications in paragraph (b)(1)(ii)(A) or (b)(1)(ii)(B) of 
this section. Such a measurement system must include compensation for 
increased or decreased flywheel torque due to the armature inertia 
during accelerations between throttle notch (test mode) settings in the 
test.
    (2) For engine testing using a locomotive alternator/generator 
instead of a dynamometer, the equipment used shall comply with the 
requirements of paragraph (a) of this section.

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