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

Table 2

Gas and Roger’s ratio codes [2].

Gas ratios	Ratio code	Range	Code
CH4/H2		≤0.1	5
		>0.1, <1.0	0
			1
		≤3.0	2
C2H6/CH4		<1.0	0
		≥1.0	1
C2H4/C2H6		<1.0	0
			1
		≥3.0	2
C2H2/C2H4		<0.5	0
			1
		≥3.0	2