[Code of Federal Regulations]
[Title 40, Volume 30]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1039.505]

[Page 501-502]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1039_CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD 
COMPRESSION-IGNITION ENGINES--Table of Contents
 
                        Subpart F_Test Procedures
 
Sec. 1039.505  How do I test engines using steady-state duty cycles, 
including ramped-modal testing?

    This section describes how to test engines under steady-state 
conditions. In some cases, we allow you to choose the appropriate 
steady-state duty cycle for an engine. In these cases, you must use the 
duty cycle you select in your application for certification for all 
testing you perform for that engine family. If we test your engines to 
confirm that they meet emission standards, we will use the duty cycles 
you select for your own testing. We may also perform other testing as 
allowed by the Clean Air Act.
    (a) You may perform steady-state testing with either discrete-mode 
or ramped-modal cycles, as follows:
    (1) For discrete-mode testing, sample emissions separately for each 
mode, then calculate an average emission level for the whole cycle using 
the weighting factors specified for each mode. Calculate cycle 
statistics for the sequence of modes and compare with the specified 
values in 40 CFR part 1065 to confirm that the test is valid. Operate 
the engine and sampling system as follows:
    (i) Engines with NOX aftertreatment. For engines that depend on 
aftertreatment to meet the NOX emission standard, operate the 
engine for 5-6 minutes, then sample emissions for 1-3 minutes in each 
mode. You may extend the sampling time to improve measurement accuracy 
of PM emissions, using good engineering judgment. If you have a longer 
sampling time for PM emissions, calculate and validate cycle statistics 
separately for the gaseous and PM sampling periods.
    (ii) Engines without NOX aftertreatment. For other engines, operate 
the engine for at least 5 minutes, then sample emissions for at least 1 
minute in each mode. Calculate cycle statistics for the sequence of 
modes and compare with the specified values in 40 CFR part 1065 to 
confirm that the test is valid.
    (2) For ramped-modal testing, start sampling at the beginning of the 
first mode and continue sampling until the end of the last mode. 
Calculate emissions and cycle statistics the same as for transient 
testing.
    (b) Measure emissions by testing the engine on a dynamometer with 
one of the following duty cycles to determine whether it meets the 
steady-state emission standards in Sec. 1039.101(b):
    (1) Use the 5-mode duty cycle or the corresponding ramped-modal 
cycle described in Appendix II of this part for constant-speed engines. 
Note that these cycles do not apply to all engines used in constant-
speed applications, as described in Sec. 1039.801.
    (2) Use the 6-mode duty cycle or the corresponding ramped-modal 
cycle described in Appendix III of this part for variable-speed engines 
below 19 kW. You may instead use the 8-mode duty cycle or the 
corresponding ramped-modal cycle described in Appendix IV of this part 
if some engines from your engine family will be used in applications 
that do not involve governing to maintain engine operation around rated 
speed.
    (3) Use the 8-mode duty cycle or the corresponding ramped-modal 
cycle described in Appendix IV of this part for variable-speed engines 
at or above 19 kW.

[[Page 502]]

    (c) During idle mode, operate the engine with the following 
parameters:
    (1) Hold the speed within your specifications.
    (2) Set the engine to operate at its minimum fueling rate.
    (3) Keep engine torque under 5 percent of maximum test torque.
    (d) For full-load operating modes, operate the engine at its maximum 
fueling rate. However, for constant-speed engines whose design prevents 
full-load operation for extended periods, you may ask for approval under 
40 CFR 1065.10(c) to replace full-load operation with the maximum load 
for which the engine is designed to operate for extended periods.
    (e) See 40 CFR part 1065 for detailed specifications of tolerances 
and calculations.
    (f) For those cases where transient testing is not necessary, 
perform the steady-state test according to this section after an 
appropriate warm-up period, consistent with 40 CFR part 1065, subpart F.