Comparative Performance Study of Dissolved Gas Analysis (DGA) Methods for Identification of Faults in Power Transformer

Table 7

Fault classification based on IEC ratio codes [9].

Ratio codes			Fault identifications
0	0	0		Normal
0	1	0	Partial discharge (low energy)
1	1	0	Partial discharge (high energy)
1	0	1	High-energy discharge
1	0	2	Low-energy discharge
0	0	1	Thermal fault , °C
0	2	0	Thermal fault , 150°C < Temp < 300°C
0	2	1	Thermal fault , 300°C < Temp < 700°C
0	2	2	Thermal fault , °C