Transformer Temperature Rise Under Cold Ambient Conditions

+10 o CInner FinTemperature ( o C)100806040top oiluppper headerinner fin - 1/4 from topinner fin - centerinner fin - 3/4 from toplower headerfreezer ambient200 10 20 30 40 50Time (hours)

Center FinTemperature ( o C)100806040top oilupper headercenter fin - topcenter fin - bottomlower headerfreezer ambient200 10 20 30 40 50Time (hours)Outer FinTemperature ( o C)100806040top oilupper headerouter fin - topouter fin - bottomouter fin - centerlower headerfreezer ambient200 10 20 30 40 50Time (hours)

HeadersTemperature ( o C)100806040top oilupper header - topupper header - averageupper header - bottomlower header - toplower header - averagelower header - bottomfreezer ambient200 10 20 30 40 50Time (hours)-30 o C

100Inner Fin80Temperature ( o C)6040200-20top oilinner fin - 1/4 from topinner fin - centerinner fin - 3/4 from top0 5 10 15 20 25 30Time (hours)100Center Fin80Temperature ( o C)6040200-20top oilambientcenter fin - topcenter fin - bottom0 5 10 15 20 25 30Time (hours)

Outer Fin10080Temperature ( o C)6040200-20top oilupper headerouter fin - topouter fin - centerouter fin - bottomlower headerambient0 5 10 15 20 25 30Time (hours)Across Fins801 hrTemperature ( o C)6040200outer fincenter fininner fin0.6hr-203 4 5 6 7 8 9 10Time (hours)

100Headers80Temperature ( o C)6040200-20upper header - topupper header - bottomlower header - toplower header - bottom0 5 10 15 20 25 30Time (hours)Comparison

Top Oil10080Temperature ( o C)6040200-20+10 o C top oil -30 o C top oil+10 o C ambient -30 o C ambient0 5 10 15 20 25Time (hours)Outer Fins100 +10 outer fin - top -30 outer fin - top80+10 outer fin - bottom -30 outer fin - bottomTemperature ( o C)6040200-200 5 10 15 20 25Time (hours)