Generator Derating. Wacker Neuson G2.5A

Operation

4.4

Generator Derating

G 2.5A

All generators are subject to derating for altitude and temperature.

Internal combustion engines, unless modified, run less efficiently at higher altitudes due to the lack of air pressure. This translates into a lack of power and thus reduction in generator output. Temperature affects both engine and generator performance. As temperature increases, an engine will run less efficiently and the more resistance will be found in electrical components. Therefore, as the temperature increases, the output of the generator decreases. Altitude also affects the cooling capacity of air—the higher the altitude the less dense the air is and thus the lower its ability to transfer heat.

For every increase in altitude of 500 m (1650 ft.) above 1000 m (3300 ft.), the output of the generator will be reduced by 3%. For every increase of 5° C (9° F) in ambient temperature above 40° C (104° F), the output of the generator will be reduced by 3%. Use the tables shown for altitude and temperature deration factors. It may be necessary to consider both altitude and ambient temperature deration factors to determine true generator output.

Ambient Temp.

°C (°F)

45 (113)

50 (122)

55 (131)

60 (140)

Derate

3 %

6 %

9 %

12 %

Factor

0.97

0.94

0.91

0.88

Altitude m (ft.)

1500 (4900)

2000 (6600)

2500 (8200)

3000 (9900)

3500 (11500)

4000 (13100)

Derate

3 %

6 %

9 %

12 %

15 %

18 %

Factor

0.97

0.94

0.91

0.88

0.85

0.82

wc_tx000158gb.fm

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