... and SG series single - phase and three - phase dry type transformer adopts high quality material and advanced technology , it has advantages ... SG series single-phase and three-phase dry type transformer)1.Ambient temperature: -15°C~+40°C 2.Altitude: <1000m 3. ... gas, steam, chemical deposition, dust or dirt that will affect transformer’s insulation seriously, also explosive or corrosive medium is not ...