Division 7.4.2.1 Test sequence for NRTC

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

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

1. (a)

   F1the 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;

2. (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;

3. (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.