Cummins ratings
Ratings are based on ISO 15550 conditions of:
- Barometric pressure 100 kPa (29.612 in Hg)
- Inlet air temperature 25°C (77°F)
- 30% relative humidity
Fuel consumption has a tolerance of +/-5% and is based on fuel of 35° API gravity at 16 °C (60 °F) having an LHV of 42,780 KJ/KG (18,390 BTU/lb) when used at 29 °C (85 °F) and weighing 838.9 g/liter (7.001 lb/US gal).
Propulsion
Continuous Duty (CON)
Intended for continuous use in applications requiring uninterrupted service at full power. This rating is an ISO 15550 standard power rating.
Heavy Duty (HD)
Intended for continuous use in variable load applications where full power is limited to eight (8) hours out of every ten (10) hours of operation. Also, reduced power operations must be at or below 200 rpm of the maximum rated rpm. This is an ISO 15550 fuel stop power rating and is for applications that operate 5,000 hours per year or less.
Medium Continuous Duty (MCD)
Intended for continuous use in variable load applications where full power is limited to six hours out of every twelve hours of operation. Also, reduced power operations must be at or below 200 rpm of the maximum rated rpm. This rating is an ISO 15550 fuel stop power rating and is for applications that operate less than 3,000 hours per year.
Intermittent Duty (INT/ID)
Intended for intermittent use in variable load applications where full power is limited to two hours out of every eight hours of operation. Also, reduced power operations must be at or below 200 rpm of the maximum rated rpm. This rating is an ISO 15550 fuel stop power rating and is for applications that operate less than 1,500 hours per year.
Government Service (GS)
Intended for intermittent use in variable load applications, where full power is limited to one hour out of every eight hours of operation. Reduced power operation must be at or below cruise speed; cruise speed is dependent on the engine rated speed. This rating is for applications operating less than 500 hours per year.