Site rates outputA deducation must made from the nominal output to VDE 0530(rated output at 40oC and 1000 m a.s.)in each of the following cases:1. Site altitude exceeds 1000 m a.s.l (ambient temperature 40oC)
Site altitude m a.s.l.100020002500300035004000
Permisible output %rated value1009491878277
If no coolant temperature is stated, it will be assumed that the altitude-induced reduction in the cooling efficiency is compensated by a lower coolant temperature.i.e.that adjustment of the maximum temperature rise to VDE 0530 is not necessary (no derating)2. Power factor cos phi<0.8
Permisible output %rated value1009692919088
3. Colant temperatur exceeds 40oC and with marie alternators to classification society rules(see Selection Tabes ).A Special inquirty should be made if coolant temperature exceeds 55 oCA collant temperature 30 oC the mean output is increased by 4% over thet permissible at coolant temperature 40oC.