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Electronic Code of Federal Regulations

e-CFR Data is current as of October 16, 2014

Title 40Chapter ISubchapter UPart 1048Subpart F → §1048.505


Title 40: Protection of Environment
PART 1048—CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES
Subpart F—Test Procedures


§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; you may also choose between discrete-mode and ramped-modal testing. In all 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. If you submit certification test data using more than one duty cycle, any of the selected duty cycles may be used for any subsequent 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 described in 40 CFR Part 1065.

(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 §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 §1048.505

C2 mode No.Engine speed1 Torque
(percent)2
Weighting
factors
1Maximum test speed250.06
2Intermediate test1000.02
3Intermediate test750.05
4Intermediate test500.32
5Intermediate test250.30
6Intermediate test100.10
7Warm idle00.15

1Speed terms are defined in 40 CFR part 1065.

2The 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 §1048.505

RMC mode Time in mode
(seconds)
Engine speed1 2 Torque
(percent)2 3
1a Steady-state119Warm idle0
1b Transition20Linear transitionLinear transition.
2a Steady-state29Intermediate speed100
2b Transition20Intermediate speedLinear transition.
3a Steady-state150Intermediate speed10
3b Transition20Intermediate speedLinear transition.
4a Steady-state80Intermediate speed75
4b Transition20Intermediate speedLinear transition.
5a Steady-state513Intermediate speed25
5b Transition20Intermediate speedLinear transition.
6a Steady-state549Intermediate speed50
6b Transition20Linear transitionLinear transition.
7a Steady-state96Maximum test speed25
7b Transition20Linear transitionLinear transition.
8 Steady-state124Warm idle0

1Speed terms are defined in 40 CFR part 1065.

2Advance 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.

3The 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 the 5-mode duty cycle or the corresponding ramped-modal cycle described in 40 CFR part 1039, Appendix II, paragraph (a).

(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 3 of §1048.505

Mode No.Engine
speed
Torque
(percent)1
Minimum time in mode (minutes)Weighting factors
1Maximum test speed1003.00.50
2Maximum test speed753.00.50

1The percent torque is relative to the maximum torque at maximum test speed.

(ii) The following duty cycle applies for discrete-mode testing:

Table 4 of §1048.505

RMC modes Time in mode
(seconds)
Engine speed
(percent)
Torque
(percent)1 2
1a Steady-state290Engine governed100
1b Transition20Engine governedLinear transition.
2 Steady-state290Engine governed75

1The percent torque is relative to maximum test torque.

2Advance 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) For full-load operating modes, operate the engine at wide-open throttle.

[73 FR 59239, Oct. 8, 2008, as amended at 75 FR 23022, Apr. 30, 2010;79 FR 23751. Apr. 28, 2014]



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