R1040 MAINTENANCE MANUAL
Page 18 of 48
Note: -
The declared power ratings of the engine are obtained at standard reference
conditions as per ISO 3046/ BS 5514/ DIN 6271/ IS 10000.
Where engines are operated at greater altitudes and or higher ambient temperatures, they
must be derated in accordance with respective standards.
Deration Charts
Deration chart for Naturally aspirated engines
The deration chart applicable for naturally aspirated engines is illustrated below.
The chart is prepared on the basis of standard ambient conditions mentioned in ISO
3046/DIN 6271/BS 5514, with 60% relative humidity. For higher relative humidity the
deration increases by 2% for 20% rise in relative humidity above 60% relative humidity.
Deration chart for 4R1040T/6R1080T engines
The deration chart applicable for R1040T/6R1080T engines is illustrated below.
