[Code of Federal Regulations]
[Title 40, Volume 31]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1048.505]
[Page 579-581]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 1048_CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD
SPARK-IGNITION ENGINES--Table of Contents
Subpart F_Test Procedures
Sec. 1048.505 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 1065.514 to confirm that the test is valid. Operate the
engine and sampling system as follows:
(i) Engines with lean NOX aftertreatment. For lean-burn 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.
(ii) Engines without lean 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 or more of the following sets of duty cycles to determine whether it
meets the steady-state emission standards in Sec. 1048.101(b):
(1) For engines from an engine family that will be used only in
variable-speed applications, use one of the following duty cycles:
(i) The following duty cycle applies for discrete-mode testing:
Table 1 of Sec. 1048.505
----------------------------------------------------------------------------------------------------------------
Minimum time
C2 Mode No. Engine speed Observed in mode Weighting
\1\ torque \2\ (minutes) factors
----------------------------------------------------------------------------------------------------------------
1............................................... Maximum test 25 3.0 0.06
speed
2............................................... Intermediate 100 3.0 0.02
test speed
3............................................... Intermediate 75 3.0 0.05
test speed
4............................................... Intermediate 50 3.0 0.32
test speed
5............................................... Intermediate 25 3.0 0.30
test speed
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6............................................... Intermediate 10 3.0 0.10
test speed
7............................................... Idle 0 3.0 0.15
----------------------------------------------------------------------------------------------------------------
\1\ Speed terms are defined in 40 CFR part 1065.
\2\ The percent torque is relative to the maximum torque at the given engine speed.
(ii) The following duty cycle applies for ramped-modal testing:
Table 2 of Sec. 1048.505
----------------------------------------------------------------------------------------------------------------
Time in mode
RMC mode (seconds) Engine speed \1,2\ Torque (percent) \2,3\
----------------------------------------------------------------------------------------------------------------
1a Steady-state..................... 119 Warm Idle.............. 0
1b Transition....................... 20 Linear Transition...... Linear Transition.
2a Steady-state..................... 29 Intermediate Speed..... 100
2b Transition....................... 20 Intermediate Speed..... Linear Transition.
3a Steady-state..................... 150 Intermediate Speed..... 10
3b Transition....................... 20 Intermediate Speed..... Linear Transition.
4a Steady-state..................... 80 Intermediate Speed..... 75
4b Transition....................... 20 Intermediate Speed..... Linear Transition.
5a Steady-state..................... 513 Intermediate Speed..... 25
5b Transition....................... 20 Intermediate Speed..... Linear Transition.
6a Steady-state..................... 549 Intermediate Speed..... 50
5b Transition....................... 20 Linear Transition...... Linear Transition.
6a Steady-state..................... 96 Maximum test speed..... 25
6b Transition....................... 20 Linear Transition...... Linear Transition.
7 Steady-state...................... 124 Warm Idle.............. 0
----------------------------------------------------------------------------------------------------------------
\1\ Speed terms are defined in 40 CFR part 1065.
\2\ Advance from one mode to the next within a 20-second transition phase. During the transition phase, command
a linear progression from the torque setting of the current mode to the torque setting of the next mode.
\3\ The percent torque is relative to maximum torque at the commanded engine speed.
(2) For engines from an engine family that will be used only at a
single, rated speed, use one of the following duty cycles:
(i) The following duty cycle applies for discrete-mode testing:
Table 3 of Sec. 1048.505
----------------------------------------------------------------------------------------------------------------
Minimum time
D2 mode No. Engine speed Torque \1\ in mode Weighting
(minutes) factors
----------------------------------------------------------------------------------------------------------------
1.................................. Maximum test............... 100 3.0 0.05
2.................................. Maximum test............... 75 3.0 0.25
3.................................. Maximum test............... 50 3.0 0.30
4.................................. Maximum test............... 25 3.0 0.30
5.................................. Maximum test............... 10 3.0 0.10
----------------------------------------------------------------------------------------------------------------
\1\ The percent torque is relative to the maximum torque at maximum test speed.
(ii) The following duty cycle applies for ramped-modal testing:
Table 4 of Sec. 1048.505
----------------------------------------------------------------------------------------------------------------
Time in mode
RMC mode (seconds) Engine speed Torque (percent) \1,2\
----------------------------------------------------------------------------------------------------------------
1a Steady-state..................... 53 Engine Governed........ 100
1b Transition....................... 20 Engine Governed........ Linear transition.
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2a Steady-state..................... 101 Engine Governed........ 10
2b Transition....................... 20 Engine Governed........ Linear transition.
3a Steady-state..................... 277 Engine Governed........ 75
3b Transition....................... 20 Engine Governed........ Linear transition.
4a Steady-state..................... 339 Engine Governed........ 25
4b Transition....................... 20 Engine Governed........ Linear transition.
5 Steady-state...................... 350 Engine Governed........ 50
----------------------------------------------------------------------------------------------------------------
\1\ The percent torque is relative to maximum test torque.
\2\ Advance from one mode to the next within a 20-second transition phase. During the transition phase, command
a linear progression from the torque setting of the current mode to the torque setting of the next mode.
(3) Use a duty cycle from both paragraphs (b)(1) and (b)(2) of this
section if you will not restrict an engine family to constant-speed or
variable-speed applications.
(4) Use a duty cycle specified in paragraph (b)(2) of this section
for all severe-duty engines.
(5) For high-load engines, use one of the following duty cycles:
(i) The following duty cycle applies for discrete-mode testing:
Table 5 of Sec. 1048.505
----------------------------------------------------------------------------------------------------------------
Minimum time
D1 mode No. Engine speed Torque \1\ in mode Weighting
(minutes) factors
----------------------------------------------------------------------------------------------------------------
1.................................. Maximum test............... 100 3.0 0.50
2.................................. Maximum test............... 75 3.0 0.50
----------------------------------------------------------------------------------------------------------------
\1\ The percent torque is relative to the maximum torque at maximum test speed.
(ii) The following duty cycle applies for discrete-mode testing:
Table 6 of Sec. 1048.505
----------------------------------------------------------------------------------------------------------------
Time in mode
RMC modes (seconds) Engine speed (percent) Torque (percent) \1,2\
----------------------------------------------------------------------------------------------------------------
1a Steady-state..................... 290 Engine Governed........ 100
1b Transition....................... 20 Engine Governed........ Linear Transition.
2 Steady-state...................... 290 Engine Governed........ 75
----------------------------------------------------------------------------------------------------------------
\1\ The percent torque is relative to maximum test torque.
\2\ Advance from one mode to the next within a 20-second transition phase. During the transition phase, command
a linear progression from the torque setting of the current mode to the torque setting of the next mode.
(c) If we test an engine to confirm that it meets the duty-cycle
emission standards, we will use the steady-state duty cycles that apply
for that engine family.
(d) 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.
(e) For full-load operating modes, operate the engine at wide-open
throttle.
(f) See 40 CFR part 1065 for detailed specifications of tolerances
and calculations.
(g) 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.
[70 FR 40476, July 13, 2005]
[[Page 582]]