Professional Detailed Explanation

1. Why Altitude Reduces Power

• Air pressure is lower → less oxygen per unit volume

• Engine combustion becomes insufficient

• Exhaust temperature rises, fuel efficiency drops

• Generator output must be derated to avoid overheating and damage

Standard Derating Formula (Industry Norm)

• 0–1,000 m above sea level: full rated power (no derating)

• Above 1,000 m:

  Power derating ≈ 3%–5% per additional 1,000 m

• Derate total ≈ 8%–10%

• Actual usable power ≈ 90–92 kW

2. High-Altitude Modified Generators 

• Adjustment of fuel injection pump (increased fuel supply)

• Optimization of ignition / combustion timing

• Larger radiator, enhanced cooling system

• Turbocharger matching or boost pressure adjustment

• Can basically recover to near-rated power

• Suitable for Tibet, Qinghai, Gansu, Yunnan highlands

3. Influence of Ambient Temperature

High Temperature (above 40°C)

• Hot air → lower air density → weaker combustion

• Cooling system efficiency decreases

• Engine easily overheats

• Power derating: ≈5%–10%

Low Temperature (below 0°C)

• Oil viscosity increases, friction rises

• Battery capacity drops, starting performance weakens

• Combustion slightly deteriorates

• Power derating: ≈3%–5%

Long-term operation in −20°C or below requires:

• Cold-start auxiliary: heater, fuel warmer, battery blanket

• Low-temperature diesel (winter grade fuel)

4. Combined Derating (Altitude + Temperature)

• 2,000 m altitude + 45°C ambient

• Altitude derate: ~4%

• Temperature derate: ~5%

• Total usable power ≈ 91% of rated

5. Professional Selection Guide

1. Altitude > 1,000 m

   → Must confirm high-altitude engine or upsize generator
2. Altitude > 2,500 m

   → Mandatory factory-calibrated plateau generator
3. Ambient > 40°C or < 0°C

   → Add cooling / heating accessories and reserve power margin
4. General rule for safe selection

   If altitude or temperature exceeds standard conditions,

   directly select a generator one level larger

   to avoid insufficient power during peak load.

Summary

• Altitude: main factor; each +1,000 m → −3%~5% power

• Temperature: high heat / severe cold both reduce output

• Highlands must use plateau-modified engines

• When in doubt, upsize the generator to ensure stable power supply