Division 5.2.5.4 Intermediate speed

The intermediate speed shall meet one of the following requirements:

1. (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;

2. (b)

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

3. (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;

4. (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.

5. (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.

6. (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.