Section

[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: 40CFR1048.505]

[Page 569-570]

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 What steady-state duty cycles apply for laboratory testing?

(a) Measure emissions by testing the engine on a dynamometer with
one or more of the following sets of steady-state duty cycles to show
that the engine meets the steady-state standards in Sec. 1048.101(b):
(1) Use the 7-mode duty cycle described in the following table for
engines from an engine family that will be used only in variable-speed
applications:

Table 1 of Sec. 1048.505--7-Mode Duty Cycle \1\
----------------------------------------------------------------------------------------------------------------
Minimum
Observed time in Weighting
Mode No. Engine speed torque \2\ mode factors
(minutes)
----------------------------------------------------------------------------------------------------------------
1....................................... Maximum test speed............. 25 3.0 0.06
2....................................... Intermediate test speed........ 100 3.0 0.02
3....................................... Intermediate test speed........ 75 3.0 0.05
4....................................... Intermediate test speed........ 50 3.0 0.32
5....................................... Intermediate test speed........ 25 3.0 0.30
6....................................... Intermediate test speed........ 10 3.0 0.10
7....................................... Idle........................... 0 3.0 0.15
----------------------------------------------------------------------------------------------------------------
\1\ This duty cycle is analogous to the C2 cycle specified in ISO 8178-4.
\2\ The percent torque is relative to the maximum torque at the given engine speed.

(2) Use the 5-mode duty cycle described in the following table if
you certify an engine family for operation only at a single, rated
speed:

Table 2 of Sec. 1048.505--5-Mode Duty Cycle for Constant-Speed Engines \1\
----------------------------------------------------------------------------------------------------------------
Minimum
time in Weighting
Mode No. Engine speed Torque \2\ mode factors
(minutes)
----------------------------------------------------------------------------------------------------------------
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\ This duty cycle is analogous to the D2 cycle specified in ISO 8178-4.
\2\ The percent torque is relative to the maximum torque at maximum test speed.

[[Page 570]]

(3) Use both of the duty cycles described in paragraphs (a)(1) and
(a)(2) of this section if you will not restrict an engine family to
constant-speed or variable-speed applications.
(4) Use only the duty cycle specified in paragraph (a)(2) of this
section for all severe-duty engines.
(5) Use the 2-mode duty cycle described in the following table for
high-load engines instead of the other duty cycles in this paragraph
(a):

Table 3 of Sec. 1048.505--2-Mode Duty Cycle for High-Load Engines \1\
----------------------------------------------------------------------------------------------------------------
Minimum
time in Weighting
Mode No. Engine speed Torque \2\ mode factors
(minutes)
----------------------------------------------------------------------------------------------------------------
1....................................... Maximum test................... 100 3.0 0.50
2....................................... Maximum test................... 75 3.0 0.50
----------------------------------------------------------------------------------------------------------------
\1\ This duty cycle is derived from the D1 cycle specified in ISO 8178-4.
\2\ The percent torque is relative to the maximum torque at maximum test speed.

(b) 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.
(c) During idle mode, operate the engine with the following
parameters:
(1) Hold the speed within your specifications.
(2) Keep the throttle at the idle-stop position.
(3) Keep engine torque under 5 percent of the peak torque value at
maximum test speed.
(d) For the full-load operating mode, operate the engine at wide-
open throttle.
(e) See 40 CFR part 1065 for detailed specifications of tolerances
and calculations.
(f) In the normal test sequence described in 40 CFR part 1065,
subpart F, steady-state testing generally follows the transient test.
For those cases where we do not require transient testing, perform the
steady-state test after an appropriate warm-up period, consistent with
good engineering judgment.