Gensets for High Altitude
At an altitude below 1,500M, the output power genset equipped with diesel engine will not decrease as the altitude rises, but at an altitude above 1,500M, power correction needs to be made for the engine and the generator. Table 1 shows the correction coefficient for environmental factors on engine power. Please refer to diesel engine manufacturers’ official data for details. The official data of Chongqing Cummins is as follows.
- Engine speed 1,800r/min, altitude below 1,525m (5,000ft), ambient temperature below 40°C (104°F)/
- Engine speed 1,500r/min, altitude below 1,525m (5,000ft), ambient temperature below 40°C (104°F)/
When the engine is running beyond the above conditions, e.g., at an altitude above 1,525m (5,000ft), the power will decrease by 4% for a rise in altitude of 300m (1,000ft); when the ambient temperature is higher than 40°C (104°F), the power will decrease by 2% for a rise in temperature of 11°C/
|Altitude||Atmospheric pressure||Air temperature|
Table 2 shows the correction coefficient of environmental factors on alternator power
Multiply corresponding correction factor by rated power
According to GB/T2819, at an altitude above 1,000m and below 3,000m, the power correction approach shall be used. At an altitude above 3,000M, it is recommended to use dedicated models for high altitude. Since power correction shall only be adopted to gensets with higher power, and the thin air at high altitude will cause reduction of the air inflow, reduced air-fuel ratio, poor burning, power decline, dark smoke coming out from the engine, heavy carbon deposition, early failure of engine oil, lubrication deterioration, increasing wear of parts as well as increased exhaust temperature, thus resulting in significantly higher engine failure rate. Dedicated engines for high altitude are designed with a reasonable air fuel ratio, reasonable turbocharger and incremental intake air filter assembly. Cooling system is also customized. It has increased the pressure of water tank pressure cap, enhanced the cooling system’s resistance to pressure and solved the problem of reduced boiling point of coolant due to the decreased atmospheric pressure, thus ensuring normal operation of the cooling system.
Dedicated generators for high altitude are designed in package. In addition to the impact of altitude environment on the diesel engines and the alternators, the impact on low-voltage electrical equipment shall also be considered. Since the electric clearance and creepage distance will be reduced as the altitude rises, derating shall be considered for low-voltage electric equipment below 690v.
Gensets for high altitude have taken into account the altitude conditions to provide customers with the most cost effective tailored generators.