Division 7.6.3.2 Mapping procedure for constant-speed NRSC

1. (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;

2. (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;

3. (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.