Effect of altitude on a transformer
The capacity of the transformer should be derated by 0.3% for each 300 feet.
Derated by 10%(8%) for 10,000feet
|Effect of high altitude|
Q: What the effect of high altitude to transformer?
A: The higher the altitude, the lesser air density. Transformer uses air as
heat dissipation medium, hence in high altitude, transformer's heat dissipation
will be restricted. The following table explains maximum allowable ambient
temperature respective to altitude and how to derate transformer loading if
ambient temperature is higher than recommended. The guidelines are found in ANSI
C57.92/81 as outlined below.
Example: Air-cooled transformer rated 1000 kVA placed at altitude of 3000 m. Derating factor is 8%, recommended maximum transformer load is 920 kVA.