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Setting a GE T35

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eeprom

Electrical
May 16, 2007
482
Hello,
I am working with a GE T35 relay, and I'm stuck on how to determine the appropriate setting for Slope 1. I have a GE document for T60 percent calculations, and it summarizes the Slope calculations as

[(delta Id)/(delta Ir)]*100%

where Id is the differential current and Ir is the restraint current. Defined as:

Id = i1_comp + i2_comp (shown as vectors)
Ir = max(|i1_comp|,|i2_comp|)

"comp" is never defined, although I assume it means magnitude compensated.

The definition of Slope 1 is the slope setting from pick-up to break 1, and it is based on CT errors during normal load currents and from tap changes.

Okay, so what I want is a clearly written equation for how I set slope 1. Does anyone have such an equation?

thanks
 
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