Commission Delegated Regulation (EU) 2017/654 of 19 December 2016 supplementing Regulation (EU) 2016/1628 of the European Parliament and of the Council with regard to technical and general requirements relating to emission limits and type-approval for internal combustion engines for non-road mobile machinery

The intermediate speed shall meet one of the following requirements:

• (a) For engines that are designed to operate over a speed range on a full load torque curve, the intermediate speed shall be the maximum torque speed if it occurs between 60 % and 75 % of rated speed;

• (b) If the maximum torque speed is less than 60 % of rated speed, then the intermediate speed shall be 60 % of the rated speed;

• (c) If the maximum torque speed is greater than 75 % of the rated speed then the intermediate speed shall be 75 % of rated speed. Where the engine is only capable of operation at speeds higher than 75 % of rated speed the intermediate speed shall be the lowest speed at which the engine can be operated;

• (d) For engines that are not designed to operate over a speed range on a full-load torque curve at steady-state conditions, the intermediate speed shall be between 60 % and 70 % of the rated speed.

• (e) For engines to be tested on cycle G1, except for engines of category ATS, the intermediate speed shall be 85 % of the rated speed.

• (f) For engines of category ATS tested on cycle G1 the intermediate speed shall be 60 % or 85 % of rated speed based on which is closer to the actual maximum torque speed.

Where the MTS is used in place of rated speed for the 100 % test speed, MTS shall also replace rated speed when determining the intermediate speed.

5.2.5.5.   Idle speed

The idle speed is the lowest engine speed with minimum load (greater than or equal to zero load), where an engine governor function controls engine speed. For engines without a governor function that controls idle speed, idle speed means the manufacturer-declared value for lowest engine speed possible with minimum load. Note that warm idle speed is the idle speed of a warmed-up engine.

5.2.5.6.   Test speed for constant-speed engines

The governors of constant-speed engines may not always maintain speed exactly constant. Typically speed can decrease (0,1 to 10) % below the speed at zero load, such that the minimum speed occurs near the engine's point of maximum power. The test speed for constant-speed engines may be commanded by using the governor installed on the engine or using a test-bed speed demand where this represents the engine governor.

Where the governor installed on the engine is used the 100 % speed shall be the engine governed speed as defined in Article 1(24).

Where a test-bed speed demand signal is used to simulate the governor, the 100 % speed at zero load shall be the no-load speed specified by the manufacturer for that governor setting and the 100 % speed at full load shall be the rated speed for that governor setting. Interpolation shall be used to determine the speed for the other test modes.

Where the governor has an isochronous operation setting, or the rated speed and no-load speed declared by the manufacturer differ by no more than 3 %, a single value declared by the manufacturer may be used for the 100 % speed at all load points.

• 5.2.6. Torque and Power

5.2.6.1   Torque

The torque figures given in the test cycles are percentage values that represent, for a given test mode, one of the following:

• (a) The ratio of the required torque to the maximum possible torque at the specified test speed (all cycles except D2 & E2);

• (b) The ratio of the required torque to the torque corresponding to the rated net power declared by the manufacturer (cycle D2 & E2).

5.2.6.2.   Power

The power figures given in the test cycles are percentage values that represent, for a given test mode, one of the following:

- (a) For the test cycle E3 the power figures are percentage values of the maximum net power at the 100 % speed as this cycle is based on a theoretical propeller characteristic curve for vessels driven by heavy-duty engines without limitation of length.

- (b) For the test cycle F the power figures are percentage values of the maximum net power at the given test speed, except for idle speed where it is a percentage of the maximum net power at the 100 % speed.

6.1.   Laboratory test conditions

The absolute temperature (T

s), expressed in kPa shall be measured and the parameter f a shall be determined in accordance with the following provisions and by means of equation (6-5) or (6-6). If the atmospheric pressure is measured in a duct, negligible pressure losses shall be ensured between the atmosphere and the measurement location, and changes in the duct's static pressure resulting from the flow shall be accounted for. In multi-cylinder engines having distinct groups of intake manifolds, such as in a ‘V’ engine configuration, the average temperature of the distinct groups shall be taken. The parameter fa shall be reported with the test results.

Naturally aspirated and mechanically supercharged engines:

Image omitted; see official source	(6-5)

Turbocharged engines with or without cooling of the intake air:

Image omitted; see official source	(6-6)

• 6.1.1. For the test to be considered valid both the following conditions must be met:

• (a) f a shall be within the range 0,93 ≤ f a ≤ 1,07 except as permitted by points 6.1.2 and 6.1.4;

• (b) The temperature of intake air shall be maintained to 298 ± 5 K (25 ± 5 °C), measured upstream of any engine component, except as permitted by points 6.1.3 and 6.1.4, and as required by points 6.1.5 and 6.1.6.

• 6.1.2. Where the altitude of the laboratory in which the engine is being tested exceeds 600 m, with the agreement of the manufacturer f a may exceed 1,07 on the condition that p s shall not be less than 80 kPa.

• 6.1.3. Where the power of the engine being tested is greater than 560 kW, with the agreement of the manufacturer the maximum value of intake air temperature may exceed 303 K (30 °C) on the condition that it shall not exceed 308 K (35 °C).

• 6.1.4. Where the altitude of the laboratory in which the engine is being tested exceeds 300 m and the power of the engine being tested is greater than 560 kW, with the agreement of the manufacturer f a may exceed 1,07 on the condition that p s shall not be less than 80 kPa and the maximum value of intake air temperature may exceed 303 K (30 °C) on the condition that it shall not exceed 308 K (35 °C).

• 6.1.5. In the case of an engine family of category NRS less than 19 kW exclusively consisting of engine types to be used in snow throwers, the temperature of the intake air shall be maintained between 273 K and 268 K (0 °C and – 5 °C).

• 6.1.6. For engines of category SMB the temperature of the intake air shall be maintained to 263 ± 5 K (– 10 ± 5 °C), except as permitted by point 6.1.6.1.

• 6.1.6.1. For engines of category SMB fitted with electronically controlled fuel injection that adjusts the fuel flow to the intake air temperature, at the choice of the manufacturer the temperature of the intake air may alternatively be maintained to 298 ± 5 K (25 ± 5 °C).

• 6.1.7. It is allowed to use:

- (a) an atmospheric pressure meter whose output is used as the atmospheric pressure for an entire test facility that has more than one dynamometer test cell, as long as the equipment for handling intake air maintains ambient pressure, where the engine is tested, within ± 1 kPa of the shared atmospheric pressure;

• (b) A humidity measurement device to measure the humidity of intake air for an entire test facility that has more than one dynamometer test cell, as long as the equipment for handling intake air maintains dew point, where the engine is tested, within ± 0,5 K of the shared humidity measurement.

6.2.   Engines with charge-air cooling

A charge-air cooling system with a total intake-air capacity that represents production engines' in-use installation shall be used. Any laboratory charge-air cooling system shall be designed to minimize accumulation of condensate. Any accumulated condensate shall be drained and all drains shall be completely closed before emission testing. The drains shall be kept closed during the emission test. Coolant conditions shall be maintained as follows:

• (a) a coolant temperature of at least 293 K (20 °C) shall be maintained at the inlet to the charge-air cooler throughout testing;

• (b) at the rated speed and full load, the coolant flow rate shall be set to achieve an air temperature within ± 5 K (± 5 °C) of the value designed by the manufacturer after the charge-air cooler's outlet. The air- outlet temperature shall be measured at the location specified by the manufacturer. This coolant flow rate set point shall be used throughout testing;

• (c) if the engine manufacturer specifies pressure-drop limits across the charge-air cooling system, it shall be ensured that the pressure drop across the charge-air cooling system at engine conditions specified by the manufacturer is within the manufacturer's specified limit(s). The pressure drop shall be measured at the manufacturer's specified locations.

When the MTS defined in point 5.2.5.1 is being used in place of rated speed to run the test cycle then this speed may be used in place of rated speed when setting the charge air temperature.

The objective is to produce emission results that are representative of in-use operation. If good engineering judgment indicates that the specifications in this section would result in unrepresentative testing (such as overcooling of the intake air), more sophisticated set points and controls of charge-air pressure drop, coolant temperature, and flow rate may be used to achieve more representative results.

6.3.   Engine power

6.3.1.   Basis for emission measurement

The basis of specific emissions measurement is uncorrected net power as defined in Article 3(25) of Regulation (EU) 2016/1628.

6.3.2.   Auxiliaries to be fitted

During the test, the auxiliaries necessary for the engine operation shall be installed on the test bench according to the requirements of Appendix 2.

Where the necessary auxiliaries cannot be fitted for the test, the power they absorb shall be determined and subtracted from the measured engine power.

6.3.3.   Auxiliaries to be removed

Certain auxiliaries whose definition is linked with the operation of the non-road mobile machinery and which may be mounted on the engine shall be removed for the test.

Where auxiliaries cannot be removed, the power they absorb in the unloaded condition may be determined and added to the measured engine power (see note g in Appendix 2). If this value is greater than 3 % of the maximum power at the test speed it may be verified by the technical service.  The power absorbed by auxiliaries shall be used to adjust the set values and to calculate the work produced by the engine over the test cycle in accordance with point 7.7.1.3 or point 7.7.2.3(b).

6.3.4.   Determination of auxiliary power

Where applicable as per point 6.3.2 and 6.3.3, the values of auxiliary power and the measurement/calculation method for determining auxiliary power shall be submitted by the engine manufacturer for the whole operating area of the applicable test cycles, and approved by the approval authority.

6.3.5.   Engine cycle work

The calculation of reference and actual cycle work (see point 7.8.3.4) shall be based upon engine power in accordance with point 6.3.1. In this case, P f and P r of equation (6-7) are zero, and P equals P m.

If auxiliaries/equipment are installed in accordance with points 6.3.2 and/or 6.3.3, the power absorbed by them shall be used to correct each instantaneous cycle power value P m,i, by means of equation (6-8):

P i = P m,i – P f,i + P r,i	(6-7)
P AUX = P r,i – P f,i	(6-8)

Where:

• P m,i is the measured engine power, kW

- P

f,i is the power absorbed by auxiliaries/equipment to be fitted for the test but that were not installed, kW

- P

r,i is the power absorbed by auxiliaries/equipment to be removed for the test but that were installed, kW.

6.4.   Engine intake air

6.4.1.   Introduction

The intake-air system installed on the engine or one that represents a typical in-use configuration shall be used. This includes the charge-air cooling and exhaust gas recirculation (EGR).

6.4.2.   Intake air pressure restriction

An engine air intake system or a test laboratory system shall be used presenting an intake air pressure restriction within ± 300 Pa of the maximum value specified by the manufacturer for a clean air cleaner at the rated speed and full load. Where this is not possible due to the design of the test laboratory air supply system a pressure restriction not exceeding the value specified by the manufacturer for a dirty filter shall be permitted subject to prior approval of the technical service. The static differential pressure of the pressure restriction shall be measured at the location and at the speed and torque set points specified by the manufacturer. If the manufacturer does not specify a location, this pressure shall be measured upstream of any turbocharger or exhaust gas recirculation (EGR) connection to the intake air system.

When the MTS defined in point 5.2.5.1 is being used in place of rated speed to run the test cycle then this speed may be used in place of rated speed when setting the intake air pressure restriction.

6.5.   Engine exhaust system

The exhaust system installed with the engine or one that represents a typical in-use configuration shall be used. The exhaust system shall conform to the requirements for exhaust emissions sampling, as set out in point 9.3. An engine exhaust system or a test laboratory system shall be used presenting a static exhaust gas back-pressure within 80 to 100 % of the maximum exhaust gas pressure restriction at the rated speed and full load. The exhaust gas pressure restriction may be set using a valve. If the maximum exhaust gas pressure restriction is 5 kPa or less, the set point shall not be more than 1,0 kPa from the maximum. When the MTS defined in point 5.2.5.1 is being used in place of rated speed to run the test cycle then this speed may be used in place of rated speed when setting the exhaust gas pressure restriction.

6.6.   Engine with exhaust after-treatment system

If the engine is equipped with an exhaust after-treatment system that is not mounted directly on the engine, the exhaust pipe shall have the same diameter as found in-use for at least four pipe diameters upstream of the expansion section containing the after-treatment device. The distance from the exhaust manifold flange or turbocharger outlet to the exhaust after-treatment system shall be the same as in the non-road mobile machinery configuration or within the distance specifications of the manufacturer. Where specified by the manufacturer the pipe shall be insulated to achieve an after-treatment inlet temperature within the specification of the manufacturer. Where other installation requirements are specified by the manufacturer these shall also be respected for the test configuration. The exhaust gas back-pressure or pressure restriction shall be set according to point 6.5. For exhaust after-treatment devices with variable exhaust gas pressure restriction, the maximum exhaust gas pressure restriction used in point 6.5 is defined at the after-treatment condition (degreening/ageing and regeneration/loading level) specified by the manufacturer. The after-treatment container may be removed during dummy tests and during engine mapping, and replaced with an equivalent container having an inactive catalyst support.

The emissions measured on the test cycle shall be representative of the emissions in the field. In the case of an engine equipped with an exhaust after-treatment system that requires the consumption of a reagent, the reagent used for all tests shall be declared by the manufacturer.

For engines of category NRE, NRG, IWP, IWA, RLR, NRS, NRSh, SMB, and ATS equipped with exhaust after-treatment systems that are regenerated on an infrequent (periodic) basis, as described in point 6.6.2, emission results shall be adjusted to account for regeneration events. In this case, the average emission depends on the frequency of the regeneration event in terms of fraction of tests during which the regeneration occurs. After-treatment systems with a regeneration process that occurs either in a sustained manner or at least once over the applicable transient (NRTC or LSI-NRTC) test cycle or RMC (‘continuous regeneration’) in accordance with point 6.6.1 do not require a special test procedure.

6.6.1.   Continuous regeneration

For an exhaust after-treatment system based on a continuous regeneration process the emissions shall be measured on an after-treatment system that has been stabilized so as to result in repeatable emissions behaviour. The regeneration process shall occur at least once during the hot-start NRTC, LSI-NRTC or NRSC test, and the manufacturer shall declare the normal conditions under which regeneration occurs (soot load, temperature, exhaust gas back-pressure, etc.). In order to demonstrate that the regeneration process is continuous, at least three hot-start runs of the NRTC, LSI-NRTC or NRSC shall be conducted. In case of hot-start NRTC, the engine shall be warmed up in accordance with point 7.8.2.1, the engine be soaked according to point 7.4.2.1(b) and the first hot-start NRTC.

The subsequent hot-start NRTC shall be started after soaking according with point 7.4.2.1(b). During the tests, exhaust gas temperatures and pressures shall be recorded (temperature before and after the exhaust after-treatment system, exhaust gas back-pressure, etc.). The exhaust after-treatment system is considered to be satisfactory if the conditions declared by the manufacturer occur during the test within a sufficient time and the emission results do not scatter by more than ± 25 % from the mean value or 0,005 g/kWh, whichever is greater.

6.6.2.   Infrequent regeneration

This provision only applies to engines equipped with an exhaust after-treatment system that is regenerated on an infrequent basis, typically occurring in less than 100 hours of normal engine operation. For those engines, either additive or multiplicative factors shall be determined for upward and downward adjustment as referred to in point 6.6.2.4 (‘adjustment factor’).

Testing and development of adjustment factors is only required for one applicable transient (NRTC or LSI-NRTC) test cycle or RMC. The factors that have been developed may be applied to results from the other applicable test cycles including discrete-mode NRSC.

In case that no suitable adjustment factors are available from testing using transient (NRTC or LSI-NRTC) test cycle or RMC then adjustment factors shall be established using an applicable discrete-mode NRSC test. Factors developed using a discrete-mode NRSC test shall only be applied to discrete-mode NRSC.

It shall not be required to conduct testing and develop adjustment factors on both RMC and discrete-mode NRSC.

6.6.2.1.   Requirement for establishing adjustment factors using NRTC, LSI-NRTC or RMC

The emissions shall be measured on at least three hot-start runs of the NRTC, LSI-NRTC or RMC, one with and two without a regeneration event on a stabilized exhaust after-treatment system. The regeneration process shall occur at least once during the NRTC, LSI-NRTC or RMC with a regeneration event. If regeneration takes longer than one NRTC, LSI-NRTC or RMC, consecutive NRTC, LSI-NRTC or RMC shall be run and emissions continued to be measured without shutting the engine off until regeneration is completed and the average of the tests shall be calculated. If regeneration is completed during any test, the test shall be continued over its entire length.

An appropriate adjustment factor shall be determined for the entire applicable cycle by means of equations (6-10) to (6-13).

6.6.2.2.   Requirement for establishing adjustment factors using discrete-mode NRSC testing

Starting with a stabilized exhaust after-treatment system the emissions shall be measured on at least three runs of each test mode of the applicable discrete-mode NRSC on which the conditions for regeneration can be met, one with and two without a regeneration event. The measurement of PM shall be conducted using the multiple filter method described in point 7.8.1.2(c). If regeneration has started but is not complete at the end of the sampling period for a specific test mode extend the sampling period shall be extended until regeneration is complete. Where there are multiple runs for the same mode an average result shall be calculated. The process shall be repeated for each test mode.

An appropriate adjustment factor shall be determined by means of equations (6-10) to (6-13) for those modes of the applicable cycle for which regeneration occurs.

6.6.2.3.   General procedure for developing infrequent regeneration adjustment factors (IRAFs)

The manufacturer shall declare the normal parameter conditions under which the regeneration process occurs (soot load, temperature, exhaust gas back-pressure, etc.). The manufacturer shall also provide the frequency of the regeneration event in terms of number of tests during which the regeneration occurs.  The exact procedure to determine this frequency shall be agreed by the approval authority based upon good engineering judgement.

For a regeneration test, the manufacturer shall provide an exhaust after-treatment system that has been loaded. Regeneration shall not occur during this engine conditioning phase. As an option, the manufacturer may run consecutive tests of the applicable cycle until the exhaust after-treatment system is loaded. Emissions measurement is not required on all tests.

Average emissions between regeneration phases shall be determined from the arithmetic mean of several approximately equidistant tests of the applicable cycle. As a minimum, at least one applicable cycle as close as possible prior to a regeneration test and one applicable cycle immediately after a regeneration test shall be conducted.

During the regeneration test, all the data needed to detect regeneration shall be recorded (CO or NOx emissions, temperature before and after the exhaust after-treatment system, exhaust gas back-pressure, etc.). During the regeneration process, the applicable emission limits may be exceeded. The test procedure is schematically shown in Figure 6.1.

Figure 6.1

Scheme of infrequent regeneration with n number of measurements and nr number of measurements during regeneration

Image omitted; see official source

The average specific emission rate related to the test runs conducted according to points 6.6.2.1 or 6.6.2.2 [g/kWh or #/kWh] shall be weighted by means of equation (6-9) (see Figure 6.1):

Image omitted; see official source	(6-9)

Where:

• n is the number of tests in which regeneration does not occur,

• n r is the number of tests in which regeneration occurs (minimum one test),

• Image omitted; see official source is the average specific emission from a test in which the regeneration does not occur [g/kWh or #/kWh]

• Image omitted; see official source is the average specific emission from a test in which the regeneration occurs [g/kWh or #/kWh]

At the choice of the manufacturer and based on upon good engineering judgment, the regeneration adjustment factor k r, expressing the average emission rate, may be calculated either multiplicative or additive for all gaseous pollutants, and, where there is an applicable limit, for PM and PN, by means of equations (6-10) to (6-13):

Multiplicative

Image omitted; see official source	(upward adjustment factor)	(6-10)
Image omitted; see official source	(downward adjustment factor)	(6-11)

Additive

Image omitted; see official source	(upward adjustment factor)	(6-12)
Image omitted; see official source	(downward adjustment factor)	(6-13)

6.6.2.4.   Application of adjustment factors

Upward adjustment factors are multiplied with or added to measured emission rates for all tests in which the regeneration does not occur. Downward adjustment factors are multiplied with or added to measured emission rates for all tests in which the regeneration occurs. The occurrence of the regeneration shall be identified in a manner that is readily apparent during all testing. Where no regeneration is identified, the upward adjustment factor shall be applied.

With reference to Annex VII and Appendix 5 of Annex VII on brake specific emission calculations, the regeneration adjustment factor:

• (a) When established for an entire weighted cycle, shall be applied to the results of the applicable weighted NRTC, LSI-NRTC and NRSC;

• (b) When established specifically for the individual modes of the applicable discrete-mode NRSC, shall be applied to the results of those modes of the applicable discrete-mode NRSC for which regeneration occurs prior to calculating the cycle weighted emission result. In this case the multiple filter method shall be used for PM measurement;

• (c) May be extended to other members of the same engine family;

• (d) May be extended to other engine families within the same engine after-treatment system family, as defined in Annex IX to Implementing Regulation (EU) 2017/656, with the prior approval of the approval authority based on technical evidence to be supplied by the manufacturer that the emissions are similar.

The following options shall apply:

- (a) A manufacturer may elect to omit adjustment factors for one or more of its engine families (or configurations) because the effect of the regeneration is small, or because it is not practical to identify when regenerations occur. In these cases, no adjustment factor shall be used, and the manufacturer is liable for compliance with the emission limits for all tests, without regard to whether a regeneration occurs;

• (b) Upon request by the manufacturer, the approval authority may account for regeneration events differently than pursuant to point (a). However, this option only applies to events that occur extremely infrequently, and which cannot be practically addressed using the adjustment factors described in point 6.6.2.3.

6.7.   Cooling system

An engine cooling system with sufficient capacity to maintain the engine, with its intake-air, oil, coolant, block and head temperatures, at normal operating temperatures prescribed by the manufacturer shall be used. Laboratory auxiliary coolers and fans may be used.

6.8.   Lubricating oil

The lubricating oil shall be specified by the manufacturer and be representative of lubricating oil available in the market; the specifications of the lubricating oil used for the test shall be recorded and presented with the results of the test.

6.9.   Specification of the reference fuel

The reference fuels to be used for the test are specified in Annex IX.

The fuel temperature shall be in accordance with the manufacturer's recommendations. The fuel temperature shall be measured at the inlet to the fuel injection pump or as specified by the manufacturer, and the location of measurement recorded.

6.10.   Crankcase emissions

This section shall apply to engines of category NRE, NRG, IWP, IWA, RLR, NRS, NRSh, SMB, & ATS complying with Stage V emission limits set out in Annex II to Regulation (EU) 2016/1628.

Crankcase emissions that are discharged directly into the ambient atmosphere shall be added to the exhaust emissions (either physically or mathematically) during all emission testing.

Manufacturers taking advantage of this exception shall install the engines so that all crankcase emission can be routed into the emissions sampling system. For the purpose of this point, crankcase emissions that are routed into the exhaust gas upstream of exhaust after-treatment system during all operation are not considered to be discharged directly into the ambient atmosphere.

Open crankcase emissions shall be routed into the exhaust system for emission measurement, as follows:

• (a) The tubing materials shall be smooth-walled, electrically conductive, and not reactive with crankcase emissions. Tube lengths shall be minimized as far as possible;

• (b) The number of bends in the laboratory crankcase tubing shall be minimized, and the radius of any unavoidable bend shall be maximized;

- (c) The laboratory crankcase exhaust tubing shall meet the engine manufacturer's specifications for crankcase back-pressure;

- (d) The crankcase exhaust tubing shall connect into the raw exhaust gas downstream of any exhaust after-treatment system, downstream of any installed exhaust emissions restriction, and sufficiently upstream of any sample probes to ensure complete mixing with the engine's exhaust system before sampling. The crankcase exhaust tube shall extend into the free stream of exhaust system to avoid boundary-layer effects and to promote mixing. The crankcase exhaust tube's outlet may orient in any direction relative to the raw exhaust gas flow.

7.1.   Introduction

This chapter describes the determination of brake specific emissions of gaseous and particulate pollutants on engines to be tested. The test engine shall be the parent engine configuration for the engine family as specified Annex IX to Implementing Regulation (EU) 2017/656.

A laboratory emission test consists of measuring emissions and other parameters for the test cycles specified in Annex XVII. The following aspects are treated:

• (a) The laboratory configurations for measuring the emissions (point 7.2);

• (b) The pre-test and post-test verification procedures (point 7.3);

• (c) The test cycles (point 7.4);

• (d) The general test sequence (point 7.5);

• (e) The engine mapping (point 7.6);

- (f) The test cycle generation (point 7.7);

• (g) The specific test cycle running procedure (point 7.8).

7.2.   Principle of emission measurement

To measure the brake-specific emissions, the engine shall be operated over the test cycles defined in point 7.4, as applicable. The measurement of brake-specific emissions requires the determination of the mass of pollutants in the exhaust emissions (i.e. HC, CO, NOx and PM), the number of particulates in the exhaust emissions (i.e. PN), the mass of CO2 in the exhaust emissions, and the corresponding engine work.

7.2.1.   Mass of constituent

The total mass of each constituent shall be determined over the applicable test cycle by using the following methods:

7.2.1.1.   Continuous sampling

In continuous sampling, the constituent's concentration is measured continuously from raw or diluted exhaust gas. This concentration is multiplied by the continuous (raw or diluted) exhaust gas flow rate at the emission sampling location to determine the constituent's flow rate. The constituent's emission is continuously summed over the test interval. This sum is the total mass of the emitted constituent.

7.2.1.2.   Batch sampling

In batch sampling, a sample of raw or diluted exhaust gas is continuously extracted and stored for later measurement. The extracted sample shall be proportional to the raw or diluted exhaust gas flow rate. Examples of batch sampling are collecting diluted gaseous emissions in a bag and collecting PM on a filter. In principal the method of emission calculation is done as follows: the batch sampled concentrations are multiplied by the total mass or mass flow (raw or dilute) from which it was extracted during the test cycle. This product is the total mass or mass flow of the emitted constituent. To calculate the PM concentration, the PM deposited onto a filter from proportionally extracted exhaust gas shall be divided by the amount of filtered exhaust gas.

7.2.1.3.   Combined sampling

Any combination of continuous and batch sampling is permitted (e.g. PM with batch sampling and gaseous emissions with continuous sampling).

Figure 6.2 illustrates the two aspects of the test procedures for measuring emissions: the equipment with the sampling lines in raw and diluted exhaust gas and the operations requested to calculate the pollutant emissions in steady-state and transient test cycles.

Figure 6.2

Test procedures for emission measurement

Image omitted; see official source Note on Figure 6.2: The term ‘Partial flow PM sampling’ includes the partial flow dilution to extract only raw exhaust gas with constant or varying dilution ratio.

7.2.2.   Work determination

The work shall be determined over the test cycle by synchronously multiplying speed and brake torque to calculate instantaneous values for engine brake power. Engine brake power shall be integrated over the test cycle to determine total work.

7.3.   Verification and calibration

7.3.1.   Pre-test procedures

7.3.1.1.   General requirements for preconditioning the sampling system and the engine

To achieve stable conditions, the sampling system and the engine shall be preconditioned before starting a test sequence as specified in this point.

The intent of engine preconditioning is to achieve the representativeness of emissions and emission controls over the duty cycle and to reduce bias in order to meet stable conditions for the following emission test.

Emissions may be measured during preconditioning cycles, as long as a predefined number of preconditioning cycles are performed and the measurement system has been started according to the requirements of point 7.3.1.4. The amount of preconditioning shall be identified by the engine manufacturer before starting to precondition. Preconditioning shall be performed as follows, noting that the specific cycles for preconditioning are the same ones that apply for emission testing.

Engines fitted with an after-treatment system may be operated prior to cycle-specific preconditioning set out in points 7.3.1.1.1 to 7.3.1.1.4, so that the after-treatment system is regenerated and, where applicable, the soot load in the particulate after-treatment system is re-established.

7.3.1.1.1.   Preconditioning for cold-start run of NRTC

The engine shall be preconditioned by running at least one hot-start NRTC. Immediately after completing each preconditioning cycle, the engine shall be shut down and the engine-off hot-soak period shall be completed. Immediately after completing the last preconditioning cycle, the engine shall be shut down and the engine cool down described in point 7.3.1.2 shall be started.

7.3.1.1.2.   Preconditioning for hot-start run of NRTC or for LSI-NRTC

This point describes the pre-conditioning that shall be applied when it is intended to sample emissions from the hot-start NRTC without running the cold-start run of the NRTC (‘cold-start NRTC’), or for the LSI-NRTC. The engine shall be preconditioned by running at least one hot-start NRTC or LSI-NRTC as applicable. Immediately after completing each preconditioning cycle, the engine shall be shut down, and then the next cycle shall be started as soon as practical. It is recommended that the next preconditioning cycle shall be started within 60 seconds after completing the last preconditioning cycle. Where applicable, following the last pre-conditioning cycle the appropriate hot-soak (hot-start NRTC) or cool-down (LSI-NRTC) period shall apply before the engine is started for the emissions test. Where no hot-soak or cool down period applies it is recommended that the emissions test shall be started within 60 seconds after completing the last pre-conditioning cycle.

7.3.1.1.3.   Preconditioning for discrete-mode NRSC

For engine categories other than NRS and NRSh the engine shall be warmed-up and run until engine temperatures (cooling water and lube oil) have been stabilized on 50 % speed and 50 % torque for any discrete-mode NRSC test cycle other than type D2, E2, or G, or nominal engine speed and 50 % torque for any discrete-mode NRSC test cycle D2, E2 or G. The 50 % speed shall be calculated in accordance with point 5.2.5.1 in the case of an engine where MTS is used for the generation of test speeds, and calculated in accordance with point 7.7.1.3 in all other cases. 50 % torque is defined as 50 % of the maximum available torque at this speed. The emissions test shall be started without stopping the engine.

For engine categories NRS and NRSh the engine shall be warmed up according to the recommendation of the manufacturer and good engineering judgment. Before emission sampling can start, the engine shall be running on mode 1 of the appropriate test cycle until engine temperatures have been stabilized. The emissions test shall be started without stopping the engine.

7.3.1.1.4.   Preconditioning for RMC

The engine manufacturer shall select one of the following pre-conditioning sequences (a) or (b). The engine shall be pre-conditioned according to the chosen sequence.

• (a) The engine shall be preconditioned by running at least the second half of the RMC, based on the number of test modes. The engine shall not be shut down between cycles. Immediately after completing each preconditioning cycle, the next cycle (including the emission test) shall be started as soon as practical. Where possible, it is recommended that the next cycle be started within 60 seconds after completing the last preconditioning cycle.

• (b) The engine shall be warmed-up and run until engine temperatures (cooling water and lube oil) have been stabilized on 50 % speed and 50 % torque for any RMC test cycle other than type D2, E2, or G, or nominal engine speed and 50 % torque for any RMC test cycle D2, E2 or G. The 50 % speed shall be calculated in accordance with point 5.2.5.1 in the case of an engine where MTS is used for the generation of test speeds, and be calculated in accordance with point 7.7.1.3 in all other cases. 50 % torque is defined as 50 % of the maximum available torque at this speed.

7.3.1.2.   Engine cool-down (NRTC)

A natural or forced cool-down procedure may be applied. For forced cool-down, good engineering judgment shall be used to set up systems to send cooling air across the engine, to send cool oil through the engine lubrication system, to remove heat from the coolant through the engine cooling system, and to remove heat from an exhaust after-treatment system. In the case of a forced after-treatment cool down, cooling air shall not be applied until the exhaust after-treatment system has cooled below its catalytic activation temperature. Any cooling procedure that results in unrepresentative emissions is not permitted.

7.3.1.3.   Verification of HC contamination

If there is any presumption of an essential HC contamination of the exhaust gas measuring system, the contamination with HC may be checked with zero gas and the hang-up may then be corrected. If the amount of contamination of the measuring system and the background HC system has to be checked, it shall be conducted within 8 hours of starting each test-cycle. The values shall be recorded for later correction. Before this check, the leak check has to be performed and the FID analyzer has to be calibrated.

7.3.1.4.   Preparation of measurement equipment for sampling

The following steps shall be taken before emission sampling begins:

• (a) Leak checks shall be performed within 8 hours prior to emission sampling in accordance with point 8.1.8.7;

• (b) For batch sampling, clean storage media shall be connected, such as evacuated bags or tare-weighed filters;

• (c) All measurement instruments shall be started in accordance with the instrument manufacturer's instructions and good engineering judgment;

• (d) Dilution systems, sample pumps, cooling fans, and the data-collection system shall be started;

• (e) The sample flow rates shall be adjusted to desired levels, using bypass flow, if desired;

• (f) Heat exchangers in the sampling system shall be pre-heated or pre-cooled to within their operating temperature ranges for a test;

• (g) Heated or cooled components such as sample lines, filters, chillers, and pumps shall be allowed to stabilize at their operating temperatures;

• (h) Exhaust gas dilution system flow shall be switched on at least 10 minutes before a test sequence;

• (i) Calibration of gas analyzers and zeroing of continuous analyzers shall be carried out in accordance with the procedure of point 7.3.1.5;

• (j) Any electronic integrating devices shall be zeroed or re-zeroed, before the start of any test interval.

7.3.1.5.   Calibration of gas analyzers

Appropriate gas analyzer ranges shall be selected. Emission analyzers with automatic or manual range switching are allowed. During a test using transient (NRTC or LSI-NRTC) test cycles or RMC and during a sampling period of a gaseous emission at the end of each mode for discrete-mode NRSC testing, the range of the emission analyzers shall not be switched. Also the gains of an analyzer's analogue operational amplifier(s) shall not be switched during a test cycle.

All continuous analyzers shall be zeroed and spanned using internationally-traceable gases that meet the specifications of point 9.5.1. FID analyzers shall be spanned on a carbon number basis of one (C1).

7.3.1.6.   PM filter preconditioning and tare weighing

The procedures for PM filter preconditioning and tare weighing shall be performed in accordance with point 8.2.3.

7.3.2.   Post-test procedures

The following steps shall be taken after emission sampling is complete:

7.3.2.1.   Verification of proportional sampling

For any proportional batch sample, such as a bag sample or PM sample, it shall be verified that proportional sampling was maintained according to point 8.2.1. For the single filter method and the discrete steady-state test cycle, effective PM weighting factor shall be calculated. Any sample that does not fulfil the requirements of point 8.2.1 shall be voided.

7.3.2.2.   Post-test PM conditioning and weighing

Used PM sample filters shall be placed into covered or sealed containers or the filter holders shall be closed, in order to protect the sample filters against ambient contamination. Thus protected, the loaded filters have to be returned to the PM-filter conditioning chamber or room. Then the PM sample filters shall be conditioned and weighted accordingly to point 8.2.4 (PM filter post-conditioning and total weighing procedures).

7.3.2.3.   Analysis of gaseous batch sampling

As soon as practical, the following shall be performed:

• (a) All batch gas analyzers shall be zeroed and spanned no later than 30 minutes after the test cycle is complete or during the soak period if practical to check if gaseous analyzers are still stable;

• (b) Any conventional gaseous batch samples shall be analyzed no later than 30 minutes after the hot-start NRTC is complete or during the soak period;

• (c) The background samples shall be analyzed no later than 60 minutes after the hot-start NRTC is complete.

7.3.2.4.   Drift verification

After quantifying exhaust gas, drift shall be verified as follows:

• (a) For batch and continuous gas analyzers, the mean analyzer value shall be recorded after stabilizing a zero gas to the analyzer. Stabilization may include time to purge the analyzer of any sample gas, plus any additional time to account for analyzer response;

- (b) The mean analyzer value shall be recorded after stabilizing the span gas to the analyzer. Stabilization may include time to purge the analyzer of any sample gas, plus any additional time to account for analyzer response;

• (c) These data shall be used to validate and correct for drift as described in point 8.2.2.

7.4.   Test cycles

The EU type-approval test shall be conducted using the appropriate NRSC and, where applicable, NRTC or LSI-NRTC, specified in Article 18 of Regulation (EU) 2016/1628 and Annex IV thereto. The technical specifications and characteristics of the NRSC, NRTC and LSI-NRTC are laid down in Annex XVII of this Regulation and the method for determination of the torque, power and speed settings for these test cycles set out in section 5.2.

7.4.1.   Steady-state test cycles

Non-road steady-state test cycles (NRSC) are specified in Appendices 1 and 2 of Annex XVII as a list of discrete-modes NRSC (operating points), where each operating point has one value of speed and one value of torque. A NRSC shall be measured with a warmed up and running engine according to manufacturer's specification. At the choice of the manufacturer, a NRSC may be run as a discrete-mode NRSC or a RMC, as explained in points 7.4.1.1 and 7.4.1.2. It shall not be required to conduct an emission test according to both points 7.4.1.1 and 7.4.1.2.

7.4.1.1.   Discrete-mode NRSC

The discrete-mode NRSC are hot running cycles where emissions shall be started to be measured after the engine is started, warmed up and running as specified in point 7.8.1.2. Each cycle consists of a number of speed and load modes (with the respective weighing factor for each mode) which cover the typical operating range of the specified engine category.

7.4.1.2.   Ramped modal NRSC

The RMC are hot running cycles where emissions shall be started to be measured after the engine is started, warmed up and running as specified in point 7.8.2.1. The engine shall be continuously controlled by the test bed control unit during the RMC. The gaseous and particulate emissions shall be measured and sampled continuously during the RMC in the same way as in a transient (NRTC or LSI-NRTC) test cycles.

An RMC is intended to provide a method for performing a steady-state test in a pseudo-transient manner. Each RMC consists of a series of steady state modes with a linear transition between them. The relative total time at each mode and its preceding transition match the weighting of the discrete-mode NRSC. The change in engine speed and load from one mode to the next one has to be linearly controlled in a time of 20 ± 1 seconds. The mode change time is part of the new mode (including the first mode). In some cases modes are not run in the same order as the discrete-mode NRSC or are split to prevent extreme changes in temperature.

7.4.2.   Transient (NRTC and LSI-NRTC) test cycles

The non-road transient cycle for engines of category NRE (NRTC) and the non-road transient cycle for large spark ignition engines of category NRS (LSI-NRTC) are each specified in Appendix 3 of Annex XVII as a second-by-second sequence of normalized speed and torque values. In order to perform the test in an engine test cell, the normalized values shall be converted to their equivalent reference values for the individual engine to be tested, based on specific speed and torque values identified in the engine-mapping curve. The conversion is referred to as denormalization, and the resulting test cycle is the reference NRTC or LSI-NRTC test cycle of the engine to be tested (see point 7.7.2).

7.4.2.1.   Test sequence for NRTC

A graphical display of the normalized NRTC dynamometer schedule is shown in Figure 6.3.

Figure 6.3

NRTC normalized dynamometer schedule

Image omitted; see official source

The NRTC shall be run twice after completion of pre-conditioning (see point 7.3.1.1.1) in accordance with the following procedure:

• (a) the cold start run shall commence after either the engine and exhaust after-treatment systems have cooled down to room temperature after natural engine cool down, or after forced cool down, and the engine, coolant and oil temperatures, exhaust after-treatment systems and all engine control devices are stabilized between 293 K and 303 K (20 °C and 30 °C). The measurement of the emissions for this run shall be started with the start of the cold engine;

• (b) the hot soak period shall commence immediately upon completion of the cold start phase. The engine shall be shut-down and conditioned for the hot-start run by soaking it for 20 minutes ± 1 minute;

• (c) the hot-start run shall commence immediately after the soak period with the cranking of the engine. The gaseous analyzers shall be switched on at least 10 seconds before the end of the soak period to avoid switching signal peaks. The measurement of emissions for this run shall be started in parallel with the cranking of the engine.

Brake specific emissions expressed in (g/kWh), or number per kilowatt-hour (#/kWh) for PN, shall be determined by using the procedures set out in this section for both the cold start run and hot-start run of the test cycle. Composite weighted emissions shall be computed by weighting the cold-start run results by 10 % and the hot-start run results by 90 % as detailed in Annex VII.

7.4.2.2.   Test sequence for LSI-NRTC

The LSI-NRTC shall be run once as a hot-start run after completion of pre-conditioning (see point 7.3.1.1.2) in accordance with the following procedure:

• (a) the engine shall be started and operated for the first 180 seconds of the duty cycle, then operated at idle without load for 30 seconds. Emissions shall not be measured during this warm-up sequence.

• (b) At the end of the 30-second idling period, emissions measurement shall be started and the engine be operated over the entire duty cycle from the beginning (time 0 sec).

Brake specific emissions expressed in (g/kWh) shall be determined by using the procedures of Annex VII.

If the engine was already operating before the test, use good engineering judgment to let the engine cool down enough so measured emissions will accurately represent those from an engine starting at room temperature. For example, if an engine starting at room temperature warms up enough in three minutes to start closed-loop operation and achieve full catalyst activity, then minimal engine cooling is necessary before starting the next test.

With the prior agreement of the technical service, the engine warm-up procedure may include up to 15 minutes of operation over the duty cycle.

7.5.   General test sequence

To measure engine emissions the following steps have to be performed:

• (a) The engine test speeds and test loads have to be defined for the engine to be tested by measuring the max torque (for constant-speed engines) or max torque curve (for variable-speed engines) as function of the engine speed;

• (b) Normalized test cycles have to be denormalized with the torque (for constant-speed engines) or speeds and torques (for variable-speed engines) found in the previous point 7.5(a);

• (c) The engine, equipment, and measurement instruments shall be prepared for the following emission test or test series (cold-start run and hot-start run) in advance;

• (d) Pre-test procedures shall be performed to verify proper operation of certain equipment and analyzers. All analysers have to be calibrated. All pre-test data shall be recorded;

• (e) The engine shall be started (NRTC) or kept running (steady-state cycles and LSI-NRTC) at the beginning of the test cycle and the sampling systems shall be started at the same time;

• (f) Emissions and other required parameters shall be measured or recorded during sampling time (for NRTC, LSI-NRTC and RMC throughout the whole test cycle);

• (g) Post-test procedures shall be performed to verify proper operation of certain equipment and analyzers;

• (h) PM filter(s) shall be pre-conditioned, weighed (empty weight), loaded, re-conditioned, again weighed (loaded weight) and then samples shall be evaluated in accordance with the pre-test (point 7.3.1.6) and post-test (point 7.3.2.2) procedures;

- (i) Emission test results shall be evaluated.

Figure 6.4 gives an overview about the procedures needed to conduct NRMM test cycles with measuring exhaust engine emissions.

Figure 6.4

Test sequence

Image omitted; see official source

7.5.1.   Engine starting, and restarting

7.5.1.1.   Engine start

The engine shall be started:

• (a) As recommended in the end-users' instructions using a production starter motor or air-start system and either an adequately charged battery, a suitable power supply or a suitable compressed air source; or

• (b) By using the dynamometer to crank the engine until it starts. Typically operate the engine within ± 25 % of its typical in-use cranking speed or start the engine by linearly increasing the dynamometer speed from zero to 100 min^– 1 below low idle speed but only until the engine starts.

Cranking shall be stopped within 1 s of starting the engine. If the engine does not start after 15 s of cranking, cranking shall be stopped and the reason for the failure to start determined, unless the end-users' instructions or the service-repair manual describes a longer cranking time as normal.

7.5.1.2.   Engine stalling

• (a) If the engine stalls anywhere during the cold start run of the NRTC, the entire test shall be voided;

• (b) If the engine stalls anywhere during the hot-start run of the NRTC, only this run shall be voided. The engine shall be soaked in accordance with point 7.8.3, and the hot-start run repeated. In this case, the cold-start run does not need to be repeated;

• (c) If the engine stalls anywhere during the LSI-NRTC, the test shall be voided.

• (d) If the engine stalls anywhere during the NRSC (discrete or ramped), the test shall be voided and be repeated beginning with the engine warm-up procedure. In the case of PM measurement utilizing the multi-filter method (one sampling filter for each operating mode), the test shall be continued by stabilizing the engine at the previous mode for engine temperature conditioning and then initiating measurement with the mode where the engine stalled.

7.5.1.3   Engine operation

The ‘operator’ may be a person (i.e., manual), or a governor (i.e., automatic) that mechanically or electronically signals an input that demands engine output. Input may be from an accelerator pedal or signal, a throttle-control lever or signal, a fuel lever or signal, a speed lever or signal, or a governor set point or signal.

7.6.   Engine mapping

Before starting the engine mapping, the engine shall be warmed up and towards the end of the warm up it shall be operated for at least 10 minutes at maximum power or according to the recommendation of the manufacturer and good engineering judgement in order to stabilize the engine coolant and lube oil temperatures. When the engine is stabilized, the engine mapping shall be performed.

Where the manufacturer intends to use the torque signal broadcast by the electronic control unit, of engines so equipped, during the conduct of in-service monitoring tests according to Delegated Regulation (EU) 2017/655 on monitoring of emissions of in-service engines, the verification set out in Appendix 3 shall additionally be performed during the engine mapping.

Except constant-speed engines, engine mapping shall be performed with fully open fuel lever or governor using discrete speeds in ascending order. The minimum and maximum mapping speeds are defined as follows:

Minimum mapping speed	=	warm idle speed
---	---	---
Maximum mapping speed	=	n hi × 1,02 or speed where max torque drops off to zero, whichever is smaller.

Where:

n

hiis the high speed,  as defined in Article 1(12).

If the highest speed is unsafe or unrepresentative (e.g., for ungoverned engines), good engineering judgement shall be used to map up to the maximum safe speed or the maximum representative speed.

7.6.1.   Engine mapping for variable-speed NRSC

In the case of engine mapping for a variable-speed NRSC (only for engines which have not to run the NRTC or LSI-NRTC cycle), good engineering judgment shall be used to select a sufficient number of evenly spaced set-points. At each set-point, speed shall be stabilized and torque allowed to stabilize at least for 15 seconds. The mean speed and torque shall be recorded at each set-point. It is recommended that the mean speed and torque are calculated using the recorded data from the last 4 to 6 seconds. Linear interpolation shall be used to determine the NRSC test speeds and torques if needed. When engines are additionally required to run an NRTC or LSI-NRTC, the NRTC engine mapping curve shall be used to determine steady-state test speeds and torques.

At the choice of the manufacturer the engine mapping may alternatively be conducted according to the procedure in point 7.6.2.

7.6.2.   Engine mapping for NRTC and LSI-NRTC

The engine mapping shall be performed according to the following procedure:

• (a) The engine shall be unloaded and operated at idle speed;
• (i) For engines with a low-speed governor, the operator demand shall be set to the minimum, the dynamometer or another loading device shall be used to target a torque of zero on the engine's primary output shaft and the engine shall be allowed to govern the speed. This warm idle speed shall be measured;
• (ii) For engines without a low-speed governor, the dynamometer shall be set to target a torque of zero on the engine's primary output shaft, and the operator demand shall be set to control the speed to the manufacturer-declared lowest engine speed possible with minimum load (also known as manufacturer-declared warm idle speed);
• (iii) The manufacturer declared idle torque may be used for all variable-speed engines (with or without a low-speed governor), if a nonzero idle torque is representative of in-use operation;

• (b) Operator demand shall be set to maximum and engine speed shall be controlled to between warm idle and 95 % of its warm idle speed. For engines with reference duty cycles, which lowest speed is greater than warm idle speed, the mapping may be started at between the lowest reference speed and 95 % of the lowest reference speed;

• (c) The engine speed shall be increased at an average rate of 8 ± 1 min^{– 1}/s or the engine shall be mapped by using a continuous sweep of speed at a constant rate such that it takes 4 to 6 min to sweep from minimum to maximum mapping speed. The mapping speed range shall be started between warm idle and 95 % of warm idle and ended at the highest speed above maximum power at which less than 70 % of maximum power occurs. If this highest speed is unsafe or unrepresentative (e.g., for ungoverned engines), good engineering judgment shall be used to map up to the maximum safe speed or the maximum representative speed. Engine speed and torque points shall be recorded at a sample rate of at least 1 Hz;

- (d) If a manufacturer believes that the above mapping techniques are unsafe or unrepresentative for any given engine, alternate mapping techniques may be used. These alternate techniques shall satisfy the intent of the specified mapping procedures to determine the maximum available torque at all engine speeds achieved during the test cycles. Deviations from the mapping techniques specified in this section for reasons of safety or representativeness shall be approved by the approval authority along with the justification for their use. In no case, however, the torque curve shall be run by descending engine speeds for governed or turbocharged engines;

• (e) An engine need not be mapped before each and every test cycle. An engine shall be remapped if:
• (i) an unreasonable amount of time has transpired since the last map, as determined by good engineering judgment; or
• (ii) physical changes or recalibrations have been made to the engine which potentially affect engine performance; or
• (iii) the atmospheric pressure near the engine's air inlet is not within ± 5 kPa of the value recorded at the time of the last engine map.

7.6.3.   Engine mapping for constant-speed NRSC

The engine may be operated with a production constant-speed governor or a constant-speed governor maybe simulated by controlling engine speed with an operator demand control system. Either isochronous or speed-droop governor operation shall be used, as appropriate.

7.6.3.1.   Rated power check for engines to be tested on cycles D2 or E2

The following check shall be conducted:

• (a) With the governor or simulated governor controlling speed using operator demand the engine shall be operated at the rated speed and the rated power for as long as required to achieve stable operation;

• (b) The torque shall be increased until the engine is unable to maintain the governed speed. The power at this point shall be recorded. Before this check is performed the method to safely determine when this point has been reached shall be agreed between the manufacturer and the technical service conducting the check, depending upon the characteristics of the governor.  The power recorded shall not exceed the rated power as defined in Article 3(27) of Regulation (EU) 2016/1628 by more than 12,5 %. If this value is exceeded the manufacturer shall revise the declared rated power.

If the specific engine being tested is unable to perform this check due to risk of damage to the engine or dynamometer the manufacturer shall present to the approval authority robust evidence that maximum power does not exceed the rated power by more than 12,5 %.

7.6.3.2.   Mapping procedure for constant-speed NRSC

• (a) With the governor or simulated governor controlling speed using operator demand, the engine shall be operated at no-load governed speed (at high speed, not low idle) for at least 15 seconds, unless the specific engine is unable to perform this task;

• (b) The dynamometer shall be used to increase torque at a constant rate. The map shall be conducted such that it takes no less than 2 min to sweep from no-load governed speed to the torque corresponding to rated power for engines to be tested on cycle D2 or E2 or to maximum torque in the case of other constant-speed test cycles. During the engine mapping actual speed and torque shall be recorded with at least 1 Hz;

• (c) In case of a constant-speed engine with a governor that can be reset to alternative speeds, the engine shall be tested at each applicable constant-speed.

For constant-speed engines good engineering judgment shall be used in agreement with the approval authority to apply other methods to record torque and power at the defined operating speed(s).

For engines tested on cycles other than D2 or E2, when both measured and declared values are available for the maximum torque, the declared value may be used instead of the measured value if it is between 95 and 100 % of the measured value.

7.7.   Test cycle generation

7.7.1.   Generation of NRSC

This point shall be used to generate the engine speeds and loads over which the engine shall be operated during steady-state tests with discrete-mode NRSC or RMC.

7.7.1.1.   Generation of NRSC test speeds for engines tested with both NRSC and either NRTC or LSI-NRTC.

For engines that are tested with either NRTC or LSI-NRTC in addition to a NRSC, the MTS specified in point 5.2.5.1 shall be used as the 100 % speed for both transient and steady state tests.

The MTS shall be used in place of rated speed when determining intermediate speed in accordance with point 5.2.5.4.

The idle speed shall be determined in accordance with point 5.2.5.5.

7.7.1.2.   Generation of NRSC test speeds for engines only tested with NRSC

For engines that are not tested with a transient (NRTC or LSI-NRTC) test cycle, the rated speed specified in point 5.2.5.3 shall be used as the 100 % speed.

The rated speed shall be used to determine the intermediate speed in accordance with point 5.2.5.4. If the NRSC specifies additional speeds as a percentage they shall be calculated as a percentage of the rated speed.

The idle speed shall be determined in accordance with point 5.2.5.5.

With prior approval of the technical service, MTS may be used instead of rated speed for the generation of test speeds in this point.

7.7.1.3.   Generation of NRSC load for each test mode

The per cent load for each test mode of the chosen test cycle shall be taken from the appropriate NRSC Table of Appendix 1 or 2 of Annex XVII. Depending upon the test cycle, the per cent load in these Tables is expressed as either power or torque in accordance with point 5.2.6 and in the footnotes for each Table.

The 100 % value at a given test speed shall be the measured or declared value taken from the mapping curve generated in accordance with point 7.6.1, point 7.6.2 or point 7.6.3 respectively, expressed as power (kW).

The engine setting for each test mode shall be calculated by means of equation (6-14):

Image omitted; see official source	(6-14)

Where:

• S is the dynamometer setting in kW

• P max is the maximum observed or declared power at the test speed under the test conditions (specified by the manufacturer) in kW

• P AUX is the declared total power absorbed by auxiliaries as defined in equation (6-8) (see point 6.3.5) at the specified test speed in kW

• L is per cent torque

A warm minimum torque that is representative of in-use operation may be declared and used for any load point that would otherwise fall below this value if the engine type will not normally operate below this minimum torque, for example because it will be connected to a non-road mobile machinery that does not operate below a certain minimum torque.

In the case of cycles E2 and D2 the manufacturer shall declare the rated power and these shall be used as 100 % power when generating the test cycle.

7.7.2.   Generation of NRTC & LSI-NRTC speed and load for each test point (denormalization)

This point shall be used to generate the corresponding engine speeds and loads over which the engine shall be operated during NRTC or LSI-NRTC tests. Appendix 3 of Annex XVII defines applicable test cycles in a normalized format. A normalized test cycle consists of a sequence of paired values for speed and torque %.

Normalized values of speed and torque shall be transformed using the following conventions:

• (a) The normalized speed shall be transformed into a sequence of reference speeds, n ref, in accordance with point 7.7.2.2;

• (b) The normalized torque is expressed as a percentage of the mapped torque from the curve generated according to point 7.6.2 at the corresponding reference speed. These normalized values shall be transformed into a sequence of reference torques, T ref, according to point 7.7.2.3;

• (c) The reference speed and reference torque values expressed in coherent units are multiplied to calculate the reference power values.

7.7.2.1.   Reserved

7.7.2.2.   Denormalization of engine speed

The engine speed shall be denormalized using by means of equation (6-15):

Image omitted; see official source	(6-15)

Where:

• n ref is the reference speed

• MTS is the maximum test speed

• n idle is the idle speed

• %speed is the value of NRTC or LSI-NRTC normalized speed taken from Appendix 3 of Annex XVII.

7.7.2.3   Denormalization of engine torque

The torque values in the engine dynamometer schedule of Appendix 3 of Annex XVII. are normalized to the maximum torque at the respective speed. The torque values of the reference cycle shall be denormalized, using the mapping curve determined according to point 7.6.2, by means of equation (6-16):

Image omitted; see official source	(6-16)

for the respective reference speed as determined in point 7.7.2.2

Where:

• T ref is the reference torque for the respective reference speed

• max.torque is the maximum torque for the respective test speed taken from the engine mapping performed in accordance with point 7.6.2 adjusted where necessary in accordance with point 7.7.2.3(b)

• %torque is the value of NRTC or LSI-NRTC normalized torque taken from Appendix 3 of Annex XVII

(a) Declared minimum torque

A minimum torque that is representative of in-use operation may be declared. For example, if the engine is typically connected to a non-road mobile machinery that does not operate below a certain minimum torque, this torque may be declared and used for any load point that would otherwise fall below this value.

(b) Adjustment of engine torque due to auxiliaries fitted for the emissions test

Where auxiliaries are fitted in accordance with Appendix 2 there shall be no adjustment to the maximum torque for the respective test speed taken from the engine mapping performed according to point 7.6.2.

Where, according to points 6.3.2 or 6.3.3 necessary auxiliaries that should have been fitted for the test are not installed, or auxiliaries that should have been removed for the test are installed, the value of T max shall be adjusted by means of equation (6-17).

T max = T map – T AUX	(6-17)

with:

TAUX = Tr – Tf	(6-18)