High Speed Diesel

For motors and generators alike, (synchronous) rpm = 120 x Hz/n_poles. Ignoring such things as 400Hz aircraft systems, Hz = 50 or 60, and n_poles is even. This effectively dictates that prime mover rpm will be in this series:

n_poles Hz rpm

2.......50..3000

4.......50..1500

6.......50..1000

8.......50...750

2.......60..3600

4.......60..1800

6.......60..1200

8.......60...900

Most engine-driven systems will fall into this range, but hydro or wind can be slower with more poles (and wave or tide even way slower, unless geared up).

Among this selection, 3000 or 3600 rpm would be considered high. (I think.) The rest of them are similar to various propulsion engines. In the truck world, 1800 rpm, and maybe 1500 rpm, is the closest match. So truck diesels can be used in DG sets.

In general, it would not be necessary to use HSD in new DG sets, but there might be special cases in which their smaller size might be desirable (offset by greater maintenance owing to the higher rpm).

Sounds to me as if he is talking about the speed of the Diesel fuel, not the speed of the engine itself. "Is it necessary to use only HSD in newly procured DG sets"

If not, then your answer is great.