differential relay slope setting.

[sethuramanj]

hello engineers, from the differential relay manual, they recommended the setting for 1st bias slope setting is 1x tap change range. my transformer got 5 tap and range is 2.5% per tap. so total range is 5% from center.so can i set 0.05 setting for 1st bias slope.

 

[pscheshki]

Who is the differential relay manufacturer?

 

[rcw retired EE]

You should also include an allowance for CT errors.

 

[stevenal]

These sound like fixed taps. Do you change taps often? If yes and no, I would use the fixed tap ratio in your tap setting calcs to keep the slope down. If they change frequently, go for a higher slope to avoid frequent protection setting changes. Slope also accommodates CT error as stated above.