Time-Current Characteristic Curves

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For your convenience, S&C’s TCC Curves have been saved in Adobe® PDF and Microsoft® Excel formats. To view the PDFs online, you’ll need Adobe’s Acrobat® Reader® software, available for free download at Adobe’s website.

Time-overcurrent relay curves marked with a star () conform to IEEE C37.112-1996, “IEEE Standard Inverse-Time Characteristic Equations for Overcurrent Relays.”

S&C Standard Speed

Curve Type	Device Type	TCC Number	PDF	Excel
Minimum Tripping	S&C Overcurrent Control	TCC Number 680-9	PDF	Excel
Total Clearing	S&C Overcurrent Control	TCC Number 680-9-2	PDF	Excel

 

S&C “K” Speed

Curve Type	Device Type	TCC Number	PDF	Excel
Minimum Tripping	S&C Overcurrent Control	TCC Number 681-9	PDF	Excel
Total Clearing	S&C Overcurrent Control	TCC Number 681-9-2	PDF	Excel

 

Tap Interrupter Speed

Curve Type	Device Type	TCC Number	PDF	Excel
Minimum Tripping	S&C Overcurrent Control	TCC Number 685-9	PDF	Excel
Total Clearing	S&C Overcurrent Control	TCC Number 685-9-2	PDF	Excel
Instantaneous	S&C Overcurrent Control	TCC Number 695-9-2		—
Definite-Time Delay Speed	S&C Overcurrent Control	TCC Number 696-9-2	PDF	—
Instantaneous and Definite-Time Delay Speed	S&C Overcurrent Control	TCC Number 697-9-2		—

 

Main Interrupter Speed

Curve Type	Device Type	TCC Number	PDF	Excel
Minimum Tripping	S&C Overcurrent Control	TCC Number 690-9	PDF	Excel
Total Clearing	S&C Overcurrent Control	TCC Number 690-9-2	PDF	Excel
Instantaneous	S&C Overcurrent Control	TCC Number 695-9-2		—
Definite-Time Delay Speed	S&C Overcurrent Control	TCC Number 696-9-2	PDF	—
Instantaneous and Definite-Time Delay Speed	S&C Overcurrent Control	TCC Number 697-9-2		—

 

Moderately Inverse Speed (U.S., U1)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 691-9-U1	PDF	Excel

 

Inverse Speed (U.S., U2)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 691-9-U2	PDF	Excel

 

Very Inverse Speed (U.S., U3)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 691-9-U3	PDF	Excel

 

Extremely Inverse Speed (U.S., U4)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 691-9-U4	PDF	Excel

 

Short-Time Inverse Speed (U.S., U5)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 691-9-U5	PDF	Excel

 

Inverse Speed (I.E.C., C1)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 692-9-C1	PDF	Excel

 

Very Inverse Speed (I.E.C., C2)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 692-9-C2	PDF	Excel

 

Extremely Inverse Speed (I.E.C., C3)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 692-9-C3	PDF	Excel

 

Long-Time Inverse Speed (I.E.C., C4)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 692-9-C4	PDF	Excel

 

Short-Time Inverse Speed (I.E.C., C5)

Curve Type	Device Type	TCC Number	PDF	Excel
Average Tripping	S&C Overcurrent Control	TCC Number 692-9-C5	PDF	Excel

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